Genome Biol , IF:10.806 , 2019 Jun , V20 (1) : P123 doi: 10.1186/s13059-019-1731-2
Cold stress induces enhanced chromatin accessibility and bivalent histone modifications H3K4me3 and H3K27me3 of active genes in potato.
Department of Horticulture, University of Wisconsin-Madison, Madison, WI, 53706, USA.; Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA.; Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA.; Department of Biological Science, College of Life Sciences, Sichuan Normal University, Chengdu, 610101, Sichuan, China.; State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agriculture University, Nanjing, 210095, Jiangsu, China.; Michigan State University AgBioResearch, East Lansing, MI, 48824, USA.; Department of Horticulture, University of Wisconsin-Madison, Madison, WI, 53706, USA. jiangjm@msu.edu.; Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA. jiangjm@msu.edu.; Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA. jiangjm@msu.edu.; Michigan State University AgBioResearch, East Lansing, MI, 48824, USA. jiangjm@msu.edu.
BACKGROUND: Cold stress can greatly affect plant growth and development. Plants have developed special systems to respond to and tolerate cold stress. While plant scientists have discovered numerous genes involved in responses to cold stress, few studies have been dedicated to investigation of genome-wide chromatin dynamics induced by cold or other abiotic stresses. RESULTS: Genomic regions containing active cis-regulatory DNA elements can be identified as DNase I hypersensitive sites (DHSs). We develop high-resolution DHS maps in potato (Solanum tuberosum) using chromatin isolated from tubers stored under room (22 degrees C) and cold (4 degrees C) conditions. We find that cold stress induces a large number of DHSs enriched in genic regions which are frequently associated with differential gene expression in response to temperature variation. Surprisingly, active genes show enhanced chromatin accessibility upon cold stress. A large number of active genes in cold-stored tubers are associated with the bivalent H3K4me3-H3K27me3 mark in gene body regions. Interestingly, upregulated genes associated with the bivalent mark are involved in stress response, whereas downregulated genes with the bivalent mark are involved in developmental processes. In addition, we observe that the bivalent mark-associated genes are more accessible than others upon cold stress. CONCLUSIONS: Collectively, our results suggest that cold stress induces enhanced chromatin accessibility and bivalent histone modifications of active genes. We hypothesize that in cold-stored tubers, the bivalent H3K4me3-H3K27me3 mark represents a distinct chromatin environment with greater accessibility, which may facilitate the access of regulatory proteins required for gene upregulation or downregulation in response to cold stress.
PMID: 31208436
New Phytol , IF:8.512 , 2019 Jun , V222 (4) : P1690-1704 doi: 10.1111/nph.15696
Advances and challenges in uncovering cold tolerance regulatory mechanisms in plants.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
Contents Summary I. Introduction II. Cold stress and physiological responses in plants III. Sensing of cold signals in plants IV. Messenger molecules involved in cold signal transduction V. Cold signal transduction in plants VI. Conclusions and perspectives Acknowledgements References SUMMARY: Cold stress is a major environmental factor that seriously affects plant growth and development, and influences crop productivity. Plants have evolved a series of mechanisms that allow them to adapt to cold stress at both the physiological and molecular levels. Over the past two decades, much progress has been made in identifying crucial components involved in cold-stress tolerance and dissecting their regulatory mechanisms. In this review, we summarize recent major advances in our understanding of cold signalling and put forward open questions in the field of plant cold-stress responses. Answering these questions should help elucidate the molecular mechanisms underlying plant tolerance to cold stress.
PMID: 30664232
Plant Physiol , IF:6.902 , 2019 Jun , V180 (2) : P966-985 doi: 10.1104/pp.18.01331
Characterization and Cloning of Grape Circular RNAs Identified the Cold Resistance-Related Vv-circATS1.
Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, People's Republic of China.; Institute of Agro-food Science and Technology/Key Laboratory of Agro-products Processing Technology of Shandong, Shandong Academy of Agricultural Sciences, Jinan 250100, People's Republic of China.; Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, People's Republic of China chaoma2015@sjtu.edu.cn.
Circular RNAs (circRNAs) are widely distributed and play essential roles in a series of developmental processes, although none have been identified or characterized in grapevines (Vitis vinifera). In this study, we characterized the function of grape circRNA and uncovered thousands of putative back-splicing sites by global transcriptome analysis. Our results indicated that several reported circRNA prediction algorithms should be used simultaneously to obtain comprehensive and reliable circRNA predictions in plants. Furthermore, the length of introns flanking grape circRNAs was closely related to exon circularization. Although the longer introns flanking grape circRNAs appeared to circularize more efficiently, a 20- to 50-nt region seemed large enough to drive grape circRNA biogenesis. In addition, the endogenous introns flanking circularized exon(s) in conjunction with reverse complementary sequences could support the accurate and efficient circularization of various exons in grape, which constitutes a new tool for exploring the functional consequences caused by circRNA expression. Finally, we identified 475 differentially expressed circRNAs in grape leaves under cold stress. Overexpression of Vv-circATS1, a circRNA derived from glycerol-3-P acyltransferase, improved cold tolerance in Arabidopsis (Arabidopsis thaliana), while the linear RNA derived from the same sequence cannot. These results indicate the functional difference between circRNA and linear RNA, and provide new insight into plant abiotic stress resistance.
PMID: 30962290
J Exp Bot , IF:5.908 , 2019 Jun , V70 (12) : P3357-3371 doi: 10.1093/jxb/erz143
New candidate loci and marker genes on chromosome 7 for improved chilling tolerance in sorghum.
Department of Agronomy, Kansas State University, Manhattan, KS, USA.; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC, USA.; Agricultural Research Center, Kansas State University, Hays, KS, USA.
Sorghum is often exposed to suboptimal low temperature stress under field conditions, particularly at the seedling establishment stage. Enhancing chilling tolerance will facilitate earlier planting and so minimize the negative impacts of other stresses experienced at later growth stages. Genome-wide association mapping was performed on a sorghum association panel grown under control (30/20 degrees C; day/night) and chilling (20/10 degrees C) conditions. Genomic regions on chromosome 7, controlling the emergence index and seedling (root and shoot) vigor, were associated with increased chilling tolerance but they did not co-localize with undesirable tannin content quantitative trait loci (QTLs). Shoot and root samples from highly contrasting haplotype pairs expressing differential responses to chilling stress were used to identify candidate genes. Three candidate genes (an alpha/beta hydrolase domain protein, a DnaJ/Hsp40 motif-containing protein, and a YTH domain-containing RNA-binding protein) were expressed at significantly higher levels under chilling stress in the tolerant haplotype compared with the sensitive haplotype and BTx623. Moreover, two CBF/DREB1A transcription factors on chromosome 2 showed a divergent response to chilling in the contrasting haplotypes. These studies identify haplotype differences on chromosome 7 that modulate chilling tolerance by either regulating CBF or feeding back into this signaling pathway. We have identified new candidate genes that will be useful markers in ongoing efforts to develop tannin-free chilling-tolerant sorghum hybrids.
PMID: 30949711
J Exp Bot , IF:5.908 , 2019 Jun , V70 (12) : P3283-3296 doi: 10.1093/jxb/erz115
Nitric oxide deficiency decreases C-repeat binding factor-dependent and -independent induction of cold acclimation.
Instituto de Biologia Molecular y Celular de Plantas (Consejo Superior de Investigaciones Cientificas-Universidad Politecnica de Valencia), Valencia, Spain.; Departamento de Biologia Medioambiental, Centro de Investigaciones Biologicas, CSIC, Madrid, Spain.
Plant tolerance to freezing temperatures is governed by endogenous components and environmental factors. Exposure to low non-freezing temperatures is a key factor in the induction of freezing tolerance in the process called cold acclimation. The role of nitric oxide (NO) in cold acclimation was explored in Arabidopsis using triple nia1nia2noa1-2 mutants that are impaired in the nitrate-dependent and nitrate-independent pathways of NO production, and are thus NO deficient. Here, we demonstrate that cold-induced NO accumulation is required to promote the full cold acclimation response through C-repeat Binding Factor (CBF)-dependent gene expression, as well as the CBF-independent expression of other cold-responsive genes such as Oxidation-Related Zinc Finger 2 (ZF/OZF2). NO deficiency also altered abscisic acid perception and signaling and the cold-induced production of anthocyanins, which are additional factors involved in cold acclimation.
PMID: 30869795
Int J Mol Sci , IF:4.556 , 2019 Jun , V20 (13) doi: 10.3390/ijms20133225
A Stress-Responsive NAC Transcription Factor from Tiger Lily (LlNAC2) Interacts with LlDREB1 and LlZHFD4 and Enhances Various Abiotic Stress Tolerance in Arabidopsis.
Beijing Key Laboratory of Ornamental Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China.; Beijing Key Laboratory of Ornamental Germplasm Innovation and Molecular Breeding, National Engineering Research Center for Floriculture, College of Landscape Architecture, Beijing Forestry University, Beijing, 100083, China. luyingmin@bjfu.edu.cn.
Our previous studies have indicated that a partial NAC domain protein gene is strongly up-regulated by cold stress (4 degrees C) in tiger lily (Lilium lancifolium). In this study, we cloned the full-length of this NAC gene, LlNAC2, to further investigate the function of LlNAC2 in response to various abiotic stresses and the possible involvement in stress tolerance of the tiger lily plant. LlNAC2 was noticeably induced by cold, drought, salt stresses, and abscisic acid (ABA) treatment. Promoter analysis showed that various stress-related cis-acting regulatory elements were located in the promoter of LlNAC2; and the promoter was sufficient to enhance activity of GUS protein under cold, salt stresses and ABA treatment. DREB1 (dehydration-responsive binding protein1) from tiger lily (LlDREB1) was proved to be able to bind to the promoter of LlNAC2 by yeast one-hybrid (Y1H) assay. LlNAC2 was shown to physically interact with LlDREB1 and zinc finger-homeodomain ZFHD4 from the tiger lily (LlZFHD4) by bimolecular fluorescence complementation (BiFC) assay. Overexpressing LlNAC2 in Arabidopsis thaliana showed ABA hypersensitivity and enhanced tolerance to cold, drought, and salt stresses. These findings indicated LlNAC2 is involved in both DREB/CBF-COR and ABA signaling pathways to regulate stress tolerance of the tiger lily.
PMID: 31262062
Int J Mol Sci , IF:4.556 , 2019 Jun , V20 (11) doi: 10.3390/ijms20112771
Transcriptome Profile Analysis of Winter Rapeseed (Brassica napus L.) in Response to Freezing Stress, Reveal Potentially Connected Events to Freezing Stress.
College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. vampirepyy@126.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. vampirepyy@126.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. liulj198910@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. wujuny@gsau.edu.cn.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. 18894310220@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. 18894310220@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. bj741912523@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. bj741912523@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. 18189560623@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. 18189560623@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. yuejinli1990@sina.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. yuejinli1990@sina.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. jiao18894310228@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. jiao18894310228@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. 15719327746@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. 15719327746@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. ffyv@163.com.; College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China. 18293121851@163.com.; Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070, China. 18293121851@163.com.
Winter rapeseed is not only an important oilseed crop, but also a winter cover crop in Northern China, where its production was severely limited by freezing stress. As an overwinter crop, the production is severely limited by freezing stress. Therefore, understanding the physiological and molecular mechanism of winter rapeseed (Brassica napus L.) in freezing stress responses becomes essential for the improvement and development of freezing-tolerant varieties of Brassica napus. In this study, morphological, physiological, ultrastructure and transcriptome changes in the Brassica napus line "2016TS(G)10" (freezing-tolerance line) that was exposed to -2 degrees C for 0 h, 1 h, 3 h and 24 h were characterized. The results showed that freezing stress caused seedling dehydration, and chloroplast dilation and degradation. The content of malondialdehyde (MDA), proline, soluble protein and soluble sugars were increased, as well as the relative electrolyte leakage (REL) which was significantly increased at frozen 24 h. Subsequently, RNA-seq analysis revealed a total of 98,672 UniGenes that were annotated in Brassica napus and 3905 UniGenes were identified as differentially expressed genes after being exposed to freezing stress. Among these genes, 2312 (59.21%) were up-regulated and 1593 (40.79%) were down-regulated. Most of these DEGs were significantly annotated in the carbohydrates and energy metabolism, signal transduction, amino acid metabolism and translation. Most of the up-regulated DEGs were especially enriched in plant hormone signal transduction, starch and sucrose metabolism pathways. Transcription factor enrichment analysis showed that the AP2/ERF, WRKY and MYB families were also significantly changed. Furthermore, 20 DEGs were selected to validate the transcriptome profiles via quantitative real-time PCR (qRT-PCR). In conclusion, the results provide an overall view of the dynamic changes in physiology and insights into the molecular regulation mechanisms of winter Brassica napus in response to freezing treatment, expanding our understanding on the complex molecular mechanism in plant response to freezing stress.
PMID: 31195741
Physiol Plant , IF:4.148 , 2019 Jun , V166 (2) : P628-645 doi: 10.1111/ppl.12811
LcFIN2, a novel chloroplast protein gene from sheepgrass, enhances tolerance to low temperature in Arabidopsis and rice.
Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China.; University of Chinese Academy of Sciences, Beijing, 100049, China.; Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, NB, E3B 4Z7, Canada.
Adverse environmental stresses affect plant growth and crop yields. Sheepgrass (Leymus chinensis (Trin.) Tzvel), an important forage grass that is widely distributed in the east of Eurasia steppe, has high tolerance to extreme low temperature. Many genes that respond to cold stress were identified in sheepgrass by RNA-sequencing, but more detailed studies are needed to dissect the function of those genes. Here, we found that LcFIN2, a sheepgrass freezing-induced protein 2, encoded a chloroplast-targeted protein. Expression of LcFIN2 was upregulated by freezing, chilling, NaCl and abscisic acid (ABA) treatments. Overexpression of LcFIN2 enhanced the survival rate of transgenic Arabidopsis after freezing stress. Importantly, heterologous expression of LcFIN2 in rice exhibited not only higher survival rate but also accumulated various soluble substances and reduced membrane damage in rice under chilling stress. Furthermore, the chlorophyll content, the quantum photochemistry efficiency of photosystem II (PhiPSII), the non-photochemical quenching (NPQ), the net photosynthesis rate (Pn) and the expression of some chloroplast ribosomal-related and photosynthesis-related genes were higher in the transgenic rice under chilling stress. These findings suggested that the LcFIN2 gene could potentially be used to improve low-temperature tolerance in crops.
PMID: 30051480
Sci Rep , IF:3.998 , 2019 Jun , V9 (1) : P8408 doi: 10.1038/s41598-019-44849-1
Identification of reliable reference genes for qRT-PCR in the ephemeral plant Arabidopsis pumila based on full-length transcriptome data.
Special Plant Genomics Laboratory, College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Special Plant Genomics Laboratory, College of Life Sciences, Shihezi University, Shihezi, Xinjiang, 832000, China. xianzhongh106@163.com.
Arabidopsis pumila, an annual ephemeral plant, plays important roles in preventing wind and sand erosion, water and soil conservation, and microhabitat improvement in the North of Xinjiang, China. Studies of adaptive mechanisms in harsh desert environments at the genetic and genomic levels can be used to more effectively develop and protect this species. The quantitative real-time polymerase chain reaction (qRT-PCR) method is one of the essential means to achieve these goals, and the selection of an appropriate reference gene is the prerequisite for qRT-PCR. In this study, 10 candidate reference genes were identified from the full-length transcriptome data of A. pumila, and their expression stabilities under four abiotic stresses (drought, heat, cold and salt) and in seven different tissues (roots, hypocotyl, cotyledon, leaves, stems, flowers and siliques) were evaluated with four programmes geNorm, NormFinder, Bestkeeper and RefFinder. Although the most stable reference genes were variable under different treatments using different software, comprehensive ranking revealed that UEP and HAF1 under drought stress, UBQ9 and GAPDH under heat stress, UBC35 and GAPDH under cold stress, GAPDH and ACT1 under salt stress, and ACT1 and GAPDH in different tissues were the most stable reference genes. Moreover, GAPDH and UBQ9 were the most suitable reference gene combinations for all samples. The expression pattern of the K(+) uptake permease gene KUP9 further validated that the selected reference genes were suitable for normalization of gene expression. The identification of reliable reference genes guarantees more accurate qRT-PCR quantification for A. pumila and facilitates functional genomics studies of ephemeral plants.
PMID: 31182737
Plant Cell Rep , IF:3.825 , 2019 Jun , V38 (6) : P699-714 doi: 10.1007/s00299-019-02398-x
The ICE-like transcription factor HbICE2 is involved in jasmonate-regulated cold tolerance in the rubber tree (Hevea brasiliensis).
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China.; Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, China. yuanhongmei@hainu.edu.cn.
KEY MESSAGE: An ICE-like transcription factor mediates jasmonate-regulated cold tolerance in the rubber tree (Hevea brasiliensis), and confers cold tolerance in transgenic Arabidopsis. The rubber tree (Hevea brasiliensis) is susceptible to low temperatures, and understanding the mechanisms regulating cold stress is of great potential value for enhancing tolerance to this environmental variable. In this study, we find that treatment with exogenous methyl jasmonate (MeJA) could significantly enhance Hevea brasiliensis cold tolerance. In addition, yeast two-hybrid and bimolecular fluorescence complementation (BiFC) experiments show that JASMONATE ZIM-DOMAIN(JAZ) proteins, HbJAZ1 and HbJAZ12, key repressors of JA signaling pathway, interact with HbICE2, a novel ICE (Inducer of CBF Expression)-like protein. HbICE2 was nuclear-localised and bound to the MYC recognition (MYCR) sequence. The transcriptional activation activity of HbICE2 in yeast cells was dependent on the N-terminus, and overexpression of HbICE2 in Arabidopsis resulted in elevated tolerance to chilling stress. Furthermore, dual-luciferase transient assay reveals that HbJAZ1 and HbJAZ12 proteins inhibit the transcriptional function of HbICE2. The expression of C-repeat-binding factor (CBF) signalling pathway genes including HbCBF1, HbCBF2 and HbCOR47 were up-regulated by MeJA. Taken together, our data suggest that the new ICE-like transcription factor HbICE2 is involved in jasmonate-regulated cold tolerance in Hevea brasiliensis.
PMID: 30830263
Genes (Basel) , IF:3.759 , 2019 Jun , V10 (6) doi: 10.3390/genes10060446
Ectopic Expression of Cold Responsive LlaCIPK Gene Enhances Cold Stress Tolerance in Nicotiana tabacum.
State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. aslampmb1@gmail.com.; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. beenishfakher@icloud.com.; Directorate of Onion and Garlic, Rajgurunagar 410505, India. anandhans@gmail.com.; Department of Biotechnology, Kumaon University Bhimtal Campus, Bhimtal 263136, India. veena_kumaun@yahoo.co.in.; Defence Institute of Bio-Energy Research, Goraparao, Haldwani 263139, India. zakwan_ahmed@rediffmail.com.; State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. yuanqin@fafu.edu.cn.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China. yuanqin@fafu.edu.cn.
Low-temperature stress severely affects the growth, development, and geographical distribution of various crop plants, resulting in significant economic loss to producers. In a quest to identify cold-regulated genes, we constructed a cDNA suppression subtractive library from a high altitude adapted ecotype of Lepidium. We cloned a cold-induced gene LlaCIPK from the subtracted cDNA library which gave homology to Arabidopsis CIPK15 gene. The predicted 3D structure of LlaCIPK protein also showed homology with Arabidopsis CIPK protein. Quantitative real-time PCR analysis in Lepidium seedlings exposed to 6 h of cold stress shows a 3-fold increase in the expression of LlaCIPK transcript. The expression of LlaCIPK was also differentially regulated by ethylene, CaCl2, ABA, and SA treatments. Ethylene and CaCl2 treatments up regulated LlaCIPK expression, whereas ABA and SA treatments down regulated the LlaCIPK expression. Transgenic plants overexpressing LlaCIPK gene under constitutive promoter show an increased level of proline and cell membrane stability. Taken together, our results suggest that the LlaCIPK contributes to the cold-response pathway in Lepidium plants.
PMID: 31212842
Genes (Basel) , IF:3.759 , 2019 Jun , V10 (6) doi: 10.3390/genes10060445
Identification of Fatty Acid Desaturases in Maize and Their Differential Responses to Low and High Temperature.
Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. zhaoxunchao2017@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. weijp81@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. linlinhe65@sina.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. byndzyf@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. zhaoying0209@hotmail.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. xuxiaoxuan3344@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. wyl8390@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. geshnan@163.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. nxdingdong@yahoo.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. nxliumeng@yahoo.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. gaoshr107@126.com.; Key Lab of Modern Agricultural Cultivation and Crop Germplasm Improvement of Heilongjiang Province, College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China. xujingyu2003@hotmail.com.
Plant fatty acid desaturases (FADs) catalyze the desaturation of fatty acids in various forms and play important roles in regulating fatty acid composition and maintaining membrane fluidity under temperature stress. A total of 30 FADs were identified from a maize genome, including 13 soluble and 17 membrane-bound FADs, which were further classified into two and five sub-groups, respectively, via phylogenetic analysis. Although there is no evolutionary relationship between the soluble and the membrane-bound FADs, they all harbor a highly conserved FA_desaturase domain, and the types and the distributions of conserved motifs are similar within each sub-group. The transcriptome analysis revealed that genes encoding FADs exhibited different expression profiles under cold and heat stresses. The expression of ZmFAD2.1&2.2, ZmFAD7, and ZmSLD1&3 were significantly up-regulated under cold stress; moreover, the expression of ZmFAD2.1&2.3 and ZmSLD1&3 were obviously down-regulated under heat stress. The co-expression analysis demonstrated close correlation among the transcription factors and the significant responsive FAD genes under cold or heat stress. This study helps to understand the roles of plant FADs in temperature stress responses.
PMID: 31210171
Genes (Basel) , IF:3.759 , 2019 Jun , V10 (6) doi: 10.3390/genes10060451
Selection of Suitable Reference Genes for RT-qPCR Gene Expression Analysis in Siberian Wild Rye (Elymus sibiricus) under Different Experimental Conditions.
The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. zhangjch16@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. xiewg@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. yuxx17@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. zhangzy17@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. zhaoyq16@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. wangn17@lzu.edu.cn.; The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China. yrwang@lzu.edu.cn.
Elymus sibiricus, which is a perennial and self-pollinated grass, is the typical species of the genus Elymus, which plays an important role in forage production and ecological restoration. No reports have, so far, systematically described the selection of optimal reference genes for reverse transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) analysis in E. sibiricus. The goals of this study were to evaluate the expression stability of 13 candidate reference genes in different experimental conditions, and to determine the appropriate reference genes for gene expression analysis in E. sibiricus. Five methods including Delta Ct (DeltaCt), BestKeeper, NormFinder, geNorm, and RefFinder were used to assess the expression stability of 13 potential reference genes. The results of the RefFinder analysis showed that TBP2 and HIS3 were the most stable reference genes in different genotypes. TUA2 and PP2A had the most stable expression in different developmental stages. TBP2 and PP2A were suitable reference genes in different tissues. Under salt stress, ACT2 and TBP2 were identified as the most stable reference genes. ACT2 and TUA2 showed the most stability under heat stress. For cold stress, PP2A and ACT2 presented the highest degree of expression stability. DNAJ and U2AF were considered as the most stable reference genes under osmotic stress. The optimal reference genes were selected to investigate the expression pattern of target gene CSLE6 in different conditions. This study provides suitable reference genes for further gene expression analysis using RT-qPCR in E. sibiricus.
PMID: 31200580
Plant Physiol Biochem , IF:3.72 , 2019 Jun , V139 : P314-324 doi: 10.1016/j.plaphy.2019.03.033
Transcriptome analysis of harvested bell peppers (Capsicum annuum L.) in response to cold stress.
Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: 254291390@qq.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: 309504752@qq.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: 403880675@qq.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: bdweisyau@163.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: 1300570891@qq.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: 958826636@qq.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: yb_zhao1979@163.com.; Department of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China. Electronic address: jsjsyau@yeah.net.
Bell peppers are valued for their plentiful vitamin C and nutritional content. Pepper fruits are susceptible to cold storage, which leads to chilling injury (CI); however, the crucial metabolic product and molecular basis response to cold stress have not been elucidated definitely yet. To comprehensively understand the gene regulation network and CI mechanisms in response to cold stress on a molecular level, we performed high-throughput RNA-Seq analysis to investigate genome-wide expression profiles in bell peppers at different storage temperatures (4 degrees C and 10 degrees C). A total of 61.55Gb of clean data were produced; 3863 differentially expressed genes (DEGs) including 1669 up-regulated and 2194 down-regulated were annotated and classified between the CI group and control. Together, a total of 41 cold-induced transcription factor families comprising 250 transcription factors (TFs) were identified. Notably, numerous DEGs involved in biomembrane stability, dehydration and osmoregulation, and plant hormone signal transduction processes were discovered. The transcriptional level of 20 DEGs was verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Our results present transcriptome profiles of bell peppers in response to cold stress; the data obtained may be useful for the identification of key candidate genes and elucidation of the mechanisms underlying membrane damage during chilling injury.
PMID: 30927694
BMC Genomics , IF:3.594 , 2019 Jun , V20 (1) : P455 doi: 10.1186/s12864-019-5852-5
Deep expression analysis reveals distinct cold-response strategies in rubber tree (Hevea brasiliensis).
Molecular Biology and Genetic Engineering Center (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil.; Department of Biology, University of Florida, Gainesville, FL, USA.; The John Bingham Laboratory, National Institute of Agricultural Botany, Cambridge, UK.; Rubber Research Advanced Center (CAPSA), Agronomical Institute (IAC), Votuporanga, SP, Brazil.; Genetics Institute, University of Florida, Gainesville, FL, USA.; Molecular Biology and Genetic Engineering Center (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil. anete@unicamp.br.; Department of Plant Biology, Biology Institute, University of Campinas (UNICAMP), Campinas, SP, Brazil. anete@unicamp.br.
BACKGROUND: Natural rubber, an indispensable commodity used in approximately 40,000 products, is fundamental to the tire industry. The rubber tree species Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell-Arg., which is native the Amazon rainforest, is the major producer of latex worldwide. Rubber tree breeding is time consuming, expensive and requires large field areas. Thus, genetic studies could optimize field evaluations, thereby reducing the time and area required for these experiments. In this work, transcriptome sequencing was used to identify a full set of transcripts and to evaluate the gene expression involved in the different cold-response strategies of the RRIM600 (cold-resistant) and GT1 (cold-tolerant) genotypes. RESULTS: We built a comprehensive transcriptome using multiple database sources, which resulted in 104,738 transcripts clustered in 49,304 genes. The RNA-seq data from the leaf tissues sampled at four different times for each genotype were used to perform a gene-level expression analysis. Differentially expressed genes (DEGs) were identified through pairwise comparisons between the two genotypes for each time series of cold treatments. DEG annotation revealed that RRIM600 and GT1 exhibit different chilling tolerance strategies. To cope with cold stress, the RRIM600 clone upregulates genes promoting stomata closure, photosynthesis inhibition and a more efficient reactive oxygen species (ROS) scavenging system. The transcriptome was also searched for putative molecular markers (single nucleotide polymorphisms (SNPs) and microsatellites) in each genotype. and a total of 27,111 microsatellites and 202,949 (GT1) and 156,395 (RRIM600) SNPs were identified in GT1 and RRIM600. Furthermore, a search for alternative splicing (AS) events identified a total of 20,279 events. CONCLUSIONS: The elucidation of genes involved in different chilling tolerance strategies associated with molecular markers and information regarding AS events provides a powerful tool for further genetic and genomic analyses of rubber tree breeding.
PMID: 31164105
Plant Sci , IF:3.591 , 2019 Jun , V283 : P329-342 doi: 10.1016/j.plantsci.2019.03.010
Cold stress affects cell wall deposition and growth pattern in tobacco pollen tubes.
Universita di Bologna, Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Via Irnerio 42, Bologna, Italy.; Universita di Siena, Dipartimento di Scienze della Vita, via P.A. Mattioli 4, Siena, Italy.; Research and Innovation Department, Luxembourg Institute of Science and Technology, 5 avenue des Hauts-Fourneaux, L-4362, Esch/Alzette, Luxembourg.; Universita di Siena, Dipartimento di Scienze della Vita, via P.A. Mattioli 4, Siena, Italy. Electronic address: giampiero.cai@unisi.it.
Cold is an abiotic stress seriously threatening crop productivity by decreasing biomass production. The pollen tube is a target of cold stress, but also a useful model to address questions on cell wall biosynthesis. We here provide (immuno)cytological data relative to the impact of cold on the pollen tube cell wall. We clearly show that the growth pattern is severely affected by the stress, since the typical pulsed-growth mechanism accompanied by the periodic deposition of pectin rings is absent/severely reduced. Additionally, pectins and cellulose accumulate in bulges provoked by the stress, while callose, which colocalizes with pectins in the periodic rings formed during pulsed growth, accumulates randomly in the stressed samples. The altered distribution of the cell wall components is accompanied by differences in the localization of glucan synthases: cellulose synthase shows a more diffuse localization, while callose synthase shows a more frequent cytoplasmic accumulation, thereby denoting a failure in plasma membrane insertion. The cell wall observations are complemented by the analysis of intracellular Ca(2+), pH and reactive oxygen species (ROS): while in the case of pH no major differences are observed, a less focused Ca(2+) and ROS gradients are present in the stressed samples. The standard oscillatory growth of pollen tubes is recovered by transient changes of turgor pressure induced by hypoosmotic media. Overall our data contribute to the understanding of the impact that cold stress has on the normal development of the pollen tube and unveil the cell wall-related aberrant features accompanying the observed alterations.
PMID: 31128704
Gene , IF:2.984 , 2019 Jun , V700 : P23-30 doi: 10.1016/j.gene.2019.02.097
De novo transcriptome sequencing and gene expression profiling of sweet potato leaves during low temperature stress and recovery.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Industrial R&D Center, Korea Scientific Technique Industry Co., Ltd., 67, Saneop-ro 92, Suwon-si 16643, Republic of Korea.; Institute of Food Crops, Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, Jiangsu, China.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Daejeon 34141, Republic of Korea; Department of Environmental Biotechnology, KRIBB School of Biotechnology, Korea University of Science and Technology (UST), 217 Gajeong-ro, Daejeon 34113, Republic of Korea. Electronic address: sskwak@kribb.re.kr.
Sweetpotato [Ipomoea batatas (L.) Lam] is an important crop used for food, animal feed, and production of industrial materials. Although it is adapted to a wide range of unfavorable conditions, including drought and high salt, sweetpotato is vulnerable to low temperature, making it difficult to cultivate in low temperature regions. To understand the molecular responses occurring in sweetpotato leaves under low temperature stress, de novo transcriptome assembly was performed in leaves under low temperature stress (LT) and during recovery (RC). In comparison with non-treated controls (NT), 2461 and 1017 differentially expressed genes (DEGs) were identified in LT and RC leaves, respectively. When expression in RC and LT samples was directly compared, 2053 DEGs were detected. To increase understanding of the DEGs, the three datasets were analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genome (KEGG) database. The CBF transcriptional cascade, a well-known cold response pathway, was investigated using transcriptomic analysis. In contrast with reports from the cold-tolerant Arabidopsis thaliana, none of the COR genes identified in sweetpotato showed increased expression in response to low temperature. Genes involved in antioxidant enzyme pathways mediating responses to reactive oxygen species (ROS) were investigated during low temperature response. This work provides insight into the molecular basis of the responses of sweetpotato to cold stress. This increased understanding of gene regulation in response to cold stress in sweetpotato will be beneficial for future research into molecular-assisted breeding.
PMID: 30898711
Plants (Basel) , IF:2.762 , 2019 Jun , V8 (6) doi: 10.3390/plants8060165
In-Cold Exposure to Z-3-Hexenal Provides Protection Against Ongoing Cold Stress in Zea mays.
Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA. jengelberth@gmx.net.; Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA. sammiesprinkles27@gmail.com.; Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA. Jurgen.engelberth@utsa.edu.
Green leaf volatiles (GLVs), which have mostly been described as providers of protection against insect herbivory and necrotrophic pathogen infections, were recently shown to provide significant fortification against cold stress damage. It was further demonstrated that cold-damaged maize seedlings released a significant amount of GLVs, in particular, Z-3-hexenal (Z-3-HAL). Here, we report that the in-cold treatment of maize seedlings with Z-3-HAL significantly improved cold stress resistance. The transcripts for cold-protective genes were also significantly increased in the Z-3-HAL treated maize seedlings over those found in only cold stressed plants. Consequently, the maize seedlings treated with HAL during cold showed a significantly increased structural integrity, significantly less damage, and increased growth after cold stress, relative to the non-HAL treated maize seedlings. Together, these results demonstrate the protective effect of in-cold treatment with HAL against cold damage, and suggest that the perception of these compounds during cold episodes significantly improves resistance against this abiotic stress.
PMID: 31212596
Funct Plant Biol , IF:2.617 , 2019 Jun , V46 (6) : P524-532 doi: 10.1071/FP18189
In silico characterisation and functional validation of chilling tolerant divergence 1 (COLD1) gene in monocots during abiotic stress.
Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India.; Genetic Transformation Lab, Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, India.; Genetic Transformation Lab, Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, India; and Corresponding authors. Emails: rsathish@buc.edu.in; cappunu@gmail.com.; Plant Genetic Engineering Laboratory, Department of Biotechnology, Bharathiar University, Coimbatore, India; and Corresponding authors. Emails: rsathish@buc.edu.in; cappunu@gmail.com.
The G protein-coupled receptor is one of the major transmembrane proteins in plants. It consists of an alpha subunit, a beta subunit and three gamma subunits. Chilling tolerant divergence 1 (COLD1) includes a Golgi pH receptor (GPHR) domain, which maintains cell membrane organisation and dynamics, along with abscisic acid linked G protein-coupled receptor (ABA_GPCR) that regulates the signalling pathways during cold stress. In the present study, we performed characterisation of a homologous COLD1 from the economically important monocot species Oryza sativa L., Zea mays L., Sorghum bicolor (L.)Moench and Erianthus arundinaceus (L.) Beauv. IK 76-81, a wild relative of Saccharum. COLD1 was isolated from E. arundinaceus IK 76-81, analysed for its evolution, domain, membrane topology, followed by prediction of secondary, tertiary structures and functionally validated in all four different monocots. Gene expression studies of COLD1 revealed differential expression under heat, drought, salinity and cold stresses in selected monocots. This is the first study on regulation of native COLD1 during abiotic stress in monocots, which has opened up new leads for trait improvement strategies in this economically important crop species.
PMID: 30940337
J Sci Food Agric , IF:2.614 , 2019 Jun , V99 (8) : P3824-3833 doi: 10.1002/jsfa.9604
Antioxidative system in sweet potato root is activated by low-temperature storage.
School of Food and Biological Engineering, Hefei University of Technology, Hefei, China.; Xuzhou Institute of Agricultural Sciences of the Xuhuai District of Jiangsu Province, Xuzhou, China.; Anhui Province Key Laboratory of Functional Compound Seasoning, Anhui Qiangwang Seasoning Food Co., Ltd., Jieshou, China.
BACKGROUND: Sweet potato is susceptible to chilling injury during low-temperature storage. To explore the correlation between chilling injury and reactive oxygen species (ROS) metabolism, the content of ROS and the activities and gene expression of antioxidant enzymes were analyzed in the typical storage-tolerant cultivar Xushu 32 and storage-sensitive cultivar Yanshu 25. RESULTS: The activities of antioxidant enzymes including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were enhanced rapidly in the early period of storage in response to chilling stress. Thereafter, the content of ROS metabolites increased consistently due to gradual decrease in ROS scavenging enzymes. Storage-tolerant cultivar Xushu 32 had higher antioxidant enzyme activities and gene expressions as well as higher content of antioxidant metabolites and lower content of ROS metabolites compared with storage-sensitive cultivar Yanshu 25, suggesting that the capacity of ROS scavenging by antioxidant enzymes and antioxidants is highly associated with the tolerance of sweet potato to chilling stress. CONCLUSION: These results indicated that the antioxidative system is activated in the storage root of sweet potato and the antioxidative capacity is positively associated with better storage performance in the storage-tolerant cultivar. (c) 2019 Society of Chemical Industry.
PMID: 30677132
J Phycol , IF:2.328 , 2019 Jun , V55 (3) : P738-743 doi: 10.1111/jpy.12854
Synergistic effects of HSE and LTR elements from hsp70 gene promoter of Ulva prolifera (Ulvophyceae, Chlorophyta) upon temperature induction(1).
CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.; College of Biotechnology Sericultural Research Institute, Jiangsu University of Science and Technology, Zhenjiang, 212018, China.
Besides heat stress, the 70 kDa heat shock proteins (HSP70s) have been shown to respond to cold stress. However, the involved cis-acting elements remain unknown. The hsp70 gene from the green macroalga Ulva prolifera (Uphsp70) has been cloned, from which one heat shock element HSE and one low-temperature-responsive element LTR were found in the promoter. Using the established transient expression system and quantitative GUS assay, a series of element deletion experiments were performed to determine the functions of HSE and LTR in response to temperature stress. The results showed that under cold stress, both HSE and LTR were indispensable, since deletion leads to complete loss of promoter activity. Under heat stress, although the HSE could respond independently, coexistence with LTR was essential for high induced activity of the Uphsp70 promoter. Therefore, synergistic effects exist between HSE and LTR elements in response to temperature stress in Ulva, and extensive bioinformatics analysis showed that the mechanism is widespread in algae and plants, since LTR coexists widely with HSE in the promoter region of hsp70. Our findings provide important supplements to the knowledge of algal and plant HSP70s response to temperature stress. We speculated that for algal domestication and artificial breeding, HSE and LTR elements might serve as potential molecular targets to temperature acclimation.
PMID: 30843209
Plant Direct , IF:1.725 , 2019 Jun , V3 (6) : Pe00149 doi: 10.1002/pld3.149
Genetic dissection of cell wall defects and the strigolactone pathway in Arabidopsis.
Institute for Plant Cell Biology and Biotechnology and Cluster of Excellence on Plant Sciences (CEPLAS) Heinrich Heine University Dusseldorf Germany.
Defects in the biosynthesis and/or deposition of secondary plant cell wall polymers result in the collapse of xylem vessels causing a dwarfed plant stature and an altered plant architecture termed irregular xylem (irx) syndrome. For example, reduced xylan O-acetylation causes strong developmental defects and increased freezing tolerance. Recently, we demonstrated that the irx syndrome in the trichome birefringence-like 29/eskimo1 (tbl29/esk1) mutant is dependent on MORE AXILLARY GROWTH 4 (MAX4), a key enzyme in the biosynthesis of the phytohormone strigolactone (SL). In this report, we show that other xylan- and cellulose-deficient secondary wall mutants exhibit increased freezing tolerance correlated with the irx syndrome. In addition, these phenotypes are also dependent on MAX4, suggesting a more general interaction between secondary wall defects and SL biosynthesis. In contrast, MAX4 does not play a role in developmental defects triggered by primary wall deficiencies, suggesting that the interaction is restricted to vascular tissue. Through a reverse genetics approach, the requirement of different components of the SL pathway impacting the irx syndrome in tbl29 was evaluated. Our results show that the tbl29-associated irx phenotypes are dependent on the MAX3 and MAX4 enzymes, involved in the early steps of SL biosynthesis. In contrast, this signaling is independent on downstream enzymes in the biosynthesis and perception of SL such as MAX1 and MAX2.
PMID: 31245785