Trends Plant Sci , IF:18.313 , 2023 Sep doi: 10.1016/j.tplants.2023.08.014
BTL2 phospho-switch surveils plant immunity.
Department of Plant Pathology, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China.; National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China.; National Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China. Electronic address: wuliuji@henau.edu.cn.; Department of Plant Pathology, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: ymwang@njau.edu.cn.
BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1) is a co-receptor involved in the recognition of pattern-associated molecular patterns (PAMPs) via plasma membrane-localized pattern recognition receptors (PRRs). Absence of BAK1/SERK4 leads to the activation of autoimmunity in plants. Yu et al. recently showed that BAK-TO-LIFE 2 (BTL2) is required for the surveillance of BAK1/SERK4 integrity to maintain immune homeostasis.
PMID: 37690906
Dev Cell , IF:12.27 , 2023 Sep , V58 (18) : P1643-1656.e5 doi: 10.1016/j.devcel.2023.07.024
Arabidopsis stomatal lineage cells establish bipolarity and segregate differential signaling capacity to regulate stem cell potential.
Department of Biology, Stanford University, Stanford, CA 94305-5020, USA; Gregor Mendel Institute, Dr.-Bohr-Gasse 3, 1030 Wien, Austria; Howard Hughes Medical Institute, Stanford, CA 94305, USA. Electronic address: ewallner@stanford.edu.; Gregor Mendel Institute, Dr.-Bohr-Gasse 3, 1030 Wien, Austria.; Department of Biology, Stanford University, Stanford, CA 94305-5020, USA; Howard Hughes Medical Institute, Stanford, CA 94305, USA. Electronic address: dbergmann@stanford.edu.
Cell polarity combined with asymmetric cell divisions (ACDs) generates cellular diversity. In the Arabidopsis stomatal lineage, a single cortical polarity domain marked by BASL orients ACDs and is segregated to the larger daughter to enforce cell fate. We discovered a second, oppositely positioned polarity domain defined by OCTOPUS-LIKE (OPL) proteins, which forms prior to ACD and is segregated to the smaller (meristemoid) daughter. Genetic and misexpression analyses show that OPLs promote meristemoid-amplifying divisions and delay stomatal fate progression. Polarity mediates OPL segregation into meristemoids but is not required for OPL function. OPL localization and activity are largely independent of other stomatal polarity genes and of the brassinosteroid signaling components associated with OPLs in other contexts. While OPLs are unique to seed plants, ectopic expression in the liverwort Marchantia suppressed epidermal fate progression, suggesting that OPLs engage ancient and broadly conserved pathways to regulate cell division and cell fate.
PMID: 37607546
Plant Cell , IF:11.277 , 2023 Sep , V35 (10) : P3782-3808 doi: 10.1093/plcell/koad200
The osmotic stress-activated receptor-like kinase DPY1 mediates SnRK2 kinase activation and drought tolerance in Setaria.
Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Center for Agricultural Genetic Resources Research, Shanxi Agricultural University, Taiyuan 030031, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.; Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Shijiazhuang 050024, China.
Plant genomes encode many receptor-like kinases (RLKs) that localize to the cell surface and perceive a wide variety of environmental cues to initiate downstream signaling cascades. Whether these RLKs participate in dehydration stress signaling in plants is largely unknown. DROOPY LEAF1 (DPY1), a leucine-rich repeat (LRR)-RLK, was recently shown to regulate plant architecture by orchestrating early brassinosteroid signaling in foxtail millet (Setaria italica). Here, we show that DPY1 is essential for the acclimation of foxtail millet to drought stress. DPY1 can be phosphorylated and activated in response to osmotic stress and is required for more than half of osmotic stress-induced global phosphorylation events, including the phosphorylation of sucrose nonfermenting kinase 2s (SnRK2s), the central kinases involved in osmotic stress. DPY1 acts upstream of STRESS-ACTIVATED PROTEIN KINASE 6 (SAPK6, a subclass I SnRK2) and is required for full SAPK6 activation, thereby allowing regulation of downstream genes to mount a response against drought stress. These signaling events are largely independent of DPY1-mediated brassinosteroid signaling. The DPY1-SAPK6 module is specific to seed plants and is absent in ancestral nonseed plants. Our findings reveal a dehydration stress-activated RLK that plays an indispensable role in osmotic stress signaling and mediates SnRK2 activation at the cell surface.
PMID: 37462269
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Sep , V120 (36) : Pe2303758120 doi: 10.1073/pnas.2303758120
Cell type-specific attenuation of brassinosteroid signaling precedes stomatal asymmetric cell division.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent 9052, Belgium.; Center for Plant Systems Biology, VIB, Ghent 9052, Belgium.; College of Life Sciences, Wuhan University, Wuhan 430072, China.; VIB Single Cell Core, VIB, Ghent 9052, Belgium.; Department of Applied Mathematics, Computer Science and Statistics, Ghent University, Ghent 9000, Belgium.; Data Mining and Modeling for Biomedicine, Center for Inflammation Research, VIB, Ghent 9052, Belgium.
In Arabidopsis thaliana, brassinosteroid (BR) signaling and stomatal development are connected through the SHAGGY/GSK3-like kinase BR INSENSITIVE2 (BIN2). BIN2 is a key negative regulator of BR signaling but it plays a dual role in stomatal development. BIN2 promotes or restricts stomatal asymmetric cell division (ACD) depending on its subcellular localization, which is regulated by the stomatal lineage-specific scaffold protein POLAR. BRs inactivate BIN2, but how they govern stomatal development remains unclear. Mapping the single-cell transcriptome of stomatal lineages after triggering BR signaling with either exogenous BRs or the specific BIN2 inhibitor, bikinin, revealed that the two modes of BR signaling activation generate spatiotemporally distinct transcriptional responses. We established that BIN2 is always sensitive to the inhibitor but, when in a complex with POLAR and its closest homolog POLAR-LIKE1, it becomes protected from BR-mediated inactivation. Subsequently, BR signaling in ACD precursors is attenuated, while it remains active in epidermal cells devoid of scaffolds and undergoing differentiation. Our study demonstrates how scaffold proteins contribute to cellular signal specificity of hormonal responses in plants.
PMID: 37639582
New Phytol , IF:10.151 , 2023 Sep , V239 (5) : P1804-1818 doi: 10.1111/nph.19049
Scaffold protein RACK1 regulates BR signaling by modulating the nuclear localization of BZR1.
Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.; Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, China.
Brassinosteroids (BRs) are a group of plant-specific steroid hormones, which induces the rapid nuclear localization of the positive transcriptional factors BRASSINAZOLE RESISTANT1/2 (BZR1/2). However, the mechanisms underlying the regulation of nucleocytoplasmic shuttling of BZR1 remain to be fully elucidated. In this study, we show that the scaffold protein Receptor for Activated C Kinase 1 (RACK1) from Arabidopsis is involved in BR signaling cascades through mediating the nuclear localization of BZR1, which is tightly retained in the cytosol by the conserved scaffold protein 14-3-3s. RACK1 can interact with BZR1 and competitively decrease the 14-3-3 interaction with BZR1 in cytosol, which efficiently enhances the nuclear localization of BZR1. 14-3-3 also retains RACK1 in cytosol through their interaction. Conversely, BR treatment enhances the nuclear localization of BZR1 by disrupting the 14-3-3 interaction with RACK1 and BZR1. Our study uncovers a new mechanism that integrates two kinds of conserved scaffold proteins (RACK1 and 14-3-3) coordinating BR signaling event.
PMID: 37301989
Plant Biotechnol J , IF:9.803 , 2023 Oct , V21 (10) : P2113-2124 doi: 10.1111/pbi.14117
PSW1, an LRR receptor kinase, regulates pod size in peanut.
College of Agronomy & Peanut Functional Genome and Molecular Breeding Engineering, Henan Agricultural University, Zhengzhou, China.; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, China.
Pod size is a key agronomic trait that greatly determines peanut yield, the regulatory genes and molecular mechanisms that controlling peanut pod size are still unclear. Here, we used quantitative trait locus analysis to identify a peanut pod size regulator, POD SIZE/WEIGHT1 (PSW1), and characterized the associated gene and protein. PSW1 encoded leucine-rich repeat receptor-like kinase (LRR-RLK) and positively regulated pod stemness. Mechanistically, this allele harbouring a 12-bp insertion in the promoter and a point mutation in the coding region of PSW1 causing a serine-to-isoleucine (S618I) substitution substantially increased mRNA abundance and the binding affinity of PSW1 for BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE 1 (BAK1). Notably, PSW1(HapII) (super-large pod allele of PSW1) expression led to up-regulation of a positive regulator of pod stemness PLETHORA 1 (PLT1), thereby resulting in larger pod size. Moreover, overexpression of PSW1(HapII) increased seed/fruit size in multiple plant species. Our work thus discovers a conserved function of PSW1 that controls pod size and provides a valuable genetic resource for breeding high-yield crops.
PMID: 37431286
Plant Biotechnol J , IF:9.803 , 2023 Oct , V21 (10) : P2125-2139 doi: 10.1111/pbi.14118
Wall-associated kinase BrWAK1 confers resistance to downy mildew in Brassica rapa.
Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences (BAAFS), Beijing, China.; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing, China.; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, China.; State Key Laboratory of Vegetable Biobreeding, Beijing, China.
The plant cell wall is the first line of defence against physical damage and pathogen attack. Wall-associated kinase (WAK) has the ability to perceive the changes in the cell wall matrix and transform signals into the cytoplasm, being involved in plant development and the defence response. Downy mildew, caused by Hyaloperonospora brassicae, can result in a massive loss in Chinese cabbage (Brassica rapa L. ssp. pekinensis) production. Herein, we identified a candidate resistant WAK gene, BrWAK1, in a major resistant quantitative trait locus, using a double haploid population derived from resistant inbred line T12-19 and the susceptible line 91-112. The expression of BrWAK1 could be induced by salicylic acid and pathogen inoculation. Expression of BrWAK1 in 91-112 could significantly enhance resistance to the pathogen, while truncating BrWAK1 in T12-19 increased disease susceptibility. Variation in the extracellular galacturonan binding (GUB) domain of BrWAK1 was found to mainly confer resistance to downy mildew in T12-19. Moreover, BrWAK1 was proved to interact with BrBAK1 (brassinosteroid insensitive 1 associated kinase), resulting in the activation of the downstream mitogen-activated protein kinase (MAPK) cascade to trigger the defence response. BrWAK1 is the first identified and thoroughly characterized WAK gene conferring disease resistance in Chinese cabbage, and the plant biomass is not significantly influenced by BrWAK1, which will greatly accelerate Chinese cabbage breeding for downy mildew resistance.
PMID: 37402218
Plant Physiol , IF:8.34 , 2023 Sep , V193 (2) : P1561-1579 doi: 10.1093/plphys/kiad399
Jasmonates regulate apical hook development by repressing brassinosteroid biosynthesis and signaling.
Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, School of Life Sciences, Guangzhou University, Guangzhou 510006, China.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.; National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; University of Chinese Academy of Sciences, Beijing 100049, China.
An apical hook is a special structure formed during skotomorphogenesis in dicotyledonous plant species. It is critical for protecting the shoot apical meristem from mechanical damage during seed germination and hypocotyl elongation in soil. Brassinosteroid (BR) and jasmonate (JA) phytohormones antagonistically regulate apical hook formation. However, the interrelationship between BRs and JAs in this process has not been well elucidated. Here, we reveal that JAs repress BRs to regulate apical hook development in Arabidopsis (Arabidopsis thaliana). Exogenous application of methyl jasmonate (MeJA) repressed the expression of the rate-limiting BR biosynthetic gene DWARF4 (DWF4) in a process relying on 3 key JA-dependent transcription factors, MYC2, MYC3, and MYC4. We demonstrated that MYC2 interacts with the critical BR-activated transcription factor BRASSINAZOLE RESISTANT 1 (BZR1), disrupting the association of BZR1 with its partner transcription factors, such as those of the PHYTOCHROME INTERACTING FACTOR (PIF) family and downregulating the expression of their target genes, such as WAVY ROOT GROWTH 2 (WAG2), encoding a protein kinase essential for apical hook development. Our results indicate that JAs not only repress the expression of BR biosynthetic gene DWF4 but, more importantly, attenuate BR signaling by inhibiting the transcriptional activation of BZR1 by MYC2 during apical hook development.
PMID: 37467431
Plant Physiol , IF:8.34 , 2023 Sep , V193 (2) : P1652-1674 doi: 10.1093/plphys/kiad371
Brassinosteroid signaling regulator BIM1 integrates brassinolide and jasmonic acid signaling during cold tolerance in apple.
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan 430074, China.; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, Shandong, China.; College of Agriculture, Shandong Agricultural University, Tai-An 271018, Shandong, China.
Although brassinolide (BR) and jasmonic acid (JA) play essential roles in the regulation of cold stress responses, the molecular basis of their crosstalk remains elusive. Here, we show a key component of BR signaling in apple (Malus x domestica), BR INSENSITIVE1 (BRI1)-EMS-SUPPRESSOR1 (BES1)-INTERACTING MYC-LIKE PROTEIN1 (MdBIM1), increases cold tolerance by directly activating expression of C-REPEAT BINDING FACTOR1 (MdCBF1) and forming a complex with C-REPEAT BINDING FACTOR2 (MdCBF2) to enhance MdCBF2-activated transcription of cold-responsive genes. Two repressors of JA signaling, JAZMONATE ZIM-DOMAIN1 (MdJAZ1) and JAZMONATE ZIM-DOMAIN2 (MdJAZ2), interact with MdBIM1 to integrate BR and JA signaling under cold stress. MdJAZ1 and MdJAZ2 reduce MdBIM1-promoted cold stress tolerance by attenuating transcriptional activation of MdCBF1 expression by MdBIM1 and interfering with the formation of the MdBIM1-MdCBF2 complex. Furthermore, the E3 ubiquitin ligase ARABIDOPSIS TOXICOS en LEVADURA73 (MdATL73) decreases MdBIM1-promoted cold tolerance by targeting MdBIM1 for ubiquitination and degradation. Our results not only reveal crosstalk between BR and JA signaling mediated by a JAZ-BIM1-CBF module but also provide insights into the posttranslational regulatory mechanism of BR signaling.
PMID: 37392474
Plant Physiol , IF:8.34 , 2023 Sep , V193 (2) : P1580-1596 doi: 10.1093/plphys/kiad353
Plant-specific BLISTER interacts with kinase BIN2 and BRASSINAZOLE RESISTANT1 during skotomorphogenesis.
State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu 210023, China.; Frontiers Science Center for Molecular Design Breeding, Key Laboratory of Crop Heterosis and Utilization (MOE), College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
Brassinosteroids play an essential role in promoting skotomorphogenesis, yet the underlying mechanisms remain unknown. Here we report that a plant-specific BLISTER (BLI) protein functions as a positive regulator of both BR signaling and skotomorphogenesis in Arabidopsis (Arabidopsis thaliana). We found that the glycogen synthase kinase 3 (GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2 interacts with and phosphorylates BLI at 4 phosphorylation sites (Ser70, Ser146, Thr256, and Ser267) for degradation; in turn, BR inhibits degradation of BLI. Specifically, BLI cooperates with the BRASSINAZOLE RESISTANT1 (BZR1) transcription factor to facilitate the transcriptional activation of BR-responsive genes. Genetic analyses indicated that BLI is essentially required for BZR1-mediated hypocotyl elongation in the dark. Intriguingly, we reveal that BLI and BZR1 orchestrate the transcriptional expression of gibberellin (GA) biosynthetic genes to promote the production of bioactive GAs. Our results demonstrate that BLI acts as an essential regulator of Arabidopsis skotomorphogenesis by promoting BR signaling and GA biosynthesis.
PMID: 37335918
J Integr Plant Biol , IF:7.061 , 2023 Sep , V65 (9) : P2175-2193 doi: 10.1111/jipb.13538
The E3 ubiquitin ligase SINA1 and the protein kinase BIN2 cooperatively regulate PHR1 in apple anthocyanin biosynthesis.
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan, 430074, China.; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, China.
PHR1 (PHOSPHATE STARVATION RESPONSE1) plays key roles in the inorganic phosphate (Pi) starvation response and in Pi deficiency-induced anthocyanin biosynthesis in plants. However, the post-translational regulation of PHR1 is unclear, and the molecular basis of PHR1-mediated anthocyanin biosynthesis remains elusive. In this study, we determined that MdPHR1 was essential for Pi deficiency-induced anthocyanin accumulation in apple (Malus x domestica). MdPHR1 interacted with MdWRKY75, a positive regulator of anthocyanin biosynthesis, to enhance the MdWRKY75-activated transcription of MdMYB1, leading to anthocyanin accumulation. In addition, the E3 ubiquitin ligase SEVEN IN ABSENTIA1 (MdSINA1) negatively regulated MdPHR1-promoted anthocyanin biosynthesis via the ubiquitination-mediated degradation of MdPHR1. Moreover, the protein kinase apple BRASSINOSTEROID INSENSITIVE2 (MdBIN2) phosphorylated MdPHR1 and positively regulated MdPHR1-mediated anthocyanin accumulation by attenuating the MdSINA1-mediated ubiquitination degradation of MdPHR1. Taken together, these findings not only demonstrate the regulatory role of MdPHR1 in Pi starvation induced anthocyanin accumulation, but also provide an insight into the post-translational regulation of PHR1.
PMID: 37272713
J Exp Bot , IF:6.992 , 2023 Sep , V74 (17) : P4978-4993 doi: 10.1093/jxb/erad196
OsBAK2/OsSERK2 expression is repressed by OsBZR1 to modulate brassinosteroid response and grain length in rice.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; Jiangsu Province Engineering Research Center of Seed Industry Science and Technology, Nanjing 210095, China.
Brassinosteroids (BRs) are a class of polyhydroxylated steroidal phytohormones that are essential for plant growth and development. Rice BRASSINOSTEROID-INSENSITIVE1 (BRI1)-ASSOCIATED RECEPTOR KINASES (OsBAKs) are plasma membrane-localized receptor kinases belonging to the subfamily of leucine-rich repeat receptor kinases. It has been found that in Arabidopsis, BRs induce the formation of a BRI1-BAK1 heterodimer complex and transmit the cascade signal to BRASSINAZOLE RESISTANT1/bri1-EMS-SUPPRESSOR1 (BZR1/BES1) to regulate BR signaling. Here, in rice (Oryza sativa ssp. japonica), we found that OsBZR1 binds directly to the promoter of OsBAK2, but not OsBAK1, and represses the expression of OsBAK2 to form a BR feedback inhibition loop. Additionally, the phosphorylation of OsBZR1 by OsGSK3 reduced its binding to the OsBAK2 promoter. The osbak2 mutant displays a typical BR-deficiency phenotype and negative modulates the accumulation of OsBZR1. Interestingly, the grain length of the osbak2 mutant was increased whereas in the cr-osbak2/cr-osbzr1 double mutant, the reduced grain length of the cr-osbzr1 mutant was restored, implying that the increased grain length of osbak2 may be due to the rice somatic embryogenesis receptor kinase-dependent pathway. Our study reveals a novel mechanism by which OsBAK2 and OsBZR1 engage in a negative feedback loop to maintain rice BR homeostasis, facilitating a deeper understanding of the BR signaling network and grain length regulation in rice.
PMID: 37235693
Plant J , IF:6.417 , 2023 Sep doi: 10.1111/tpj.16464
DWARF AND LOW-TILLERING 2 functions in brassinosteroid signaling and controls plant architecture and grain size in rice.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.; Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, Sichuan, China.; Technical Center of Chengdu Customs, Chengdu, 610041, Sichuan, China.
Brassinosteroids (BRs) are a class of steroid phytohormones that control various aspects of plant growth and development. Several transcriptional factors (TFs) have been suggested to play roles in BR signaling. However, their possible relationship remains largely unknown. Here, we identified a rice mutant dwarf and low-tillering 2 (dlt2) with altered plant architecture, increased grain width, and reduced BR sensitivity. DLT2 encodes a GIBBERELLIN INSENSITIVE (GAI)-REPRESSOR OF GAI (RGA)-SCARECROW (GRAS) TF that is mainly localized in the nucleus and has weak transcriptional activity. Our further genetic and biochemical analyses indicate that DLT2 interacts with two BR-signaling-related TFs, DLT and BRASSINAZOLE-RESISTANT 1, and probably modulates their transcriptional activity. These findings imply that DLT2 is implicated in a potentially transcriptional complex that mediates BR signaling and rice development and suggests that DLT2 could be a potential target for improving rice architecture and grain morphology. This work also sheds light on the role of rice GRAS members in regulating numerous developmental processes.
PMID: 37699038
Plant J , IF:6.417 , 2023 Sep , V115 (6) : P1729-1745 doi: 10.1111/tpj.16353
Cell cycle-dependent kinase inhibitor GhKRP6, a direct target of GhBES1.4, participates in BR regulation of cell expansion in cotton.
College of Agronomy, Shenyang Agricultural University, Shenyang, 110161, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, Henan, China.; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, Henan, China.; Key Laboratory of China Northwestern Inland Region, Ministry of Agriculture and Rural Affairs, Cotton Research Institute, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, 832003, China.; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, Xinjiang, China.
The steroidal hormone brassinosteroid (BR) has been shown to positively regulate cell expansion in plants. However, the specific mechanism by which BR controls this process has not been fully understood. In this study, RNA-seq and DAP-seq analysis of GhBES1.4 (a core transcription factor in BR signaling) were used to identify a cotton cell cycle-dependent kinase inhibitor called GhKRP6. The study found that GhKRP6 was significantly induced by the BR hormone and that GhBES1.4 directly promoted the expression of GhKRP6 by binding to the CACGTG motif in its promoter region. GhKRP6-silenced cotton plants had smaller leaves with more cells and reduced cell size. Furthermore, endoreduplication was inhibited, which affected cell expansion and ultimately decreased fiber length and seed size in GhKRP6-silenced plants compared with the control. The KEGG enrichment results of control and VIGS-GhKRP6 plants revealed differential expression of genes related to cell wall biosynthesis, MAPK, and plant hormone transduction pathways - all of which are related to cell expansion. Additionally, some cyclin-dependent kinase (CDK) genes were upregulated in the plants with silenced GhKRP6. Our study also found that GhKRP6 could interact directly with a cell cycle-dependent kinase called GhCDKG. Taken together, these results suggest that BR signaling influences cell expansion by directly modulating the expression of cell cycle-dependent kinase inhibitor GhKRP6 via GhBES1.4.
PMID: 37326240
Plant Sci , IF:4.729 , 2023 Oct , V335 : P111788 doi: 10.1016/j.plantsci.2023.111788
Brassinosteroid catabolic enzyme CYP734A129 regulates the morphologies of leaves and floral organs in woodland strawberry.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China. Electronic address: ckang@mail.hzau.edu.cn.
Brassinosteroids (BRs) play critical roles in plant growth and development and regulate many important agronomic traits. However, the functions of BRs in strawberry are unclear. This study identified two mutants, named P6 and R87, in woodland strawberry (Fragaria vesca) from EMS mutagenesis populations that exhibit narrow leaves, petals and sepals. Mapping by sequencing and genetic studies revealed that the F. vesca CYP734A129, encoding a putative BR catabolic enzyme, is the causative gene for both P6 and R87. Overexpression of CYP734A129 in both F. vesca and Arabidopsis causes a severe dwarf phenotype, and the BRI1-EMS-SUPPRESSOR 1 (BES1) protein is less abundant in the CYP734A129-overexpressing Arabidopsis seedlings. This suggests that CYP734A129 is functionally conserved with CYP734A1, as a BR-inactivating enzyme. Transcriptome analysis of young leaves revealed that four BR biosynthetic genes were significantly downregulated in P6 (cyp734a129), and photosynthesis-related genes were highly enriched among the up-regulated genes in P6 compared to the wild type. This further supports that CYP734A129 inactivates BRs in F. vesca. Furthermore, we showed that mutations in CYP734A129 do not affect fruit shape and color during ripening in strawberry. Overall, our results suggest that F. vesca CYP734A129 is a BR catabolic enzyme, and provide insights into the roles of CYP734A129 in strawberry.
PMID: 37421982
Plant Sci , IF:4.729 , 2023 Sep , V334 : P111764 doi: 10.1016/j.plantsci.2023.111764
Improved production and quality of peppers irrigated with regenerated water by the application of 24-epibrassinolide.
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain. Electronic address: martapinto@ub.edu.; Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain.; Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain; Research Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain.
Water shortage for crop irrigation is reducing agricultural production worldwide and the use of sewage treatment plant (STP) water to irrigate horticultural fields is a solution to avoid the use of drinkable water in agriculture. In this study, two different genotypes of pepper (Red Cherry Small and Italian green) were irrigated with STP water, as an alternative to potable water. Moreover, the foliar application of a molecule with biostimulant properties (24-epibrassinolide; EBR) was tested as a strategy to ameliorate the production and quality of fruits. Both genotypes differed on their tolerance to the suffered oxidative stress due to their different salinity tolerance, but fruit commercial weight was reduced by 49% on the salt sensitive and by 37% on the salt tolerant. Moreover, ascorbic acid was also decreased by 37% after STP water irrigation in the Red Cherry Small peppers. However, EBR applications alleviated STP watering stress effects improving pepper plants fruit production and quality parameters, such as ascorbic acid and capsaicinoids. These results have important economic and environmental relevance to overcome present and future water deficiencies in the agricultural sector derived from climate change, guaranteeing the maintenance of production in peppers irrigated with STP water for a more sustainable agriculture following relevant circular economy actions.
PMID: 37301327
Plant Physiol Biochem , IF:4.27 , 2023 Sep , V202 : P107972 doi: 10.1016/j.plaphy.2023.107972
PpBZR1, a BES/BZR transcription factor, enhances cold stress tolerance by suppressing sucrose degradation in peach fruit.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, 315800, China.; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, 315800, China. Electronic address: chenyi@nbu.edu.cn.; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo, 315800, China. Electronic address: shaoxingfeng@nbu.edu.cn.
Brassinosteroids (BRs) are phytohormones that play numerous roles in a plant's response to environmental stress. While BES/BZR transcription factors are essential components in BR signaling, their role in regulating postharvest fruit responses to cold stress is largely unknown. In this study, the application of 24-epibrassinolide (EBR) to peaches alleviated chilling injury (CI) during postharvest cold storage. We further characterized a key BES/BZR gene, PpBZR1, which regulates peach cold resistance. Transient expression PpBZR1 in peaches showed that PpBZR1 inhibits PpVIN2 expression and VIN activity, resulting in an elevated level of sucrose, which protects fruit from CI. Arabidopsis thaliana expressing PpBZR1 that had a high germination and seedling survival rate at low temperatures, which may be due to higher level of sucrose and lower oxidative damage. Mechanistically, we confirmed that PpBZR1 directly binds to the PpVIN2 promoter and functions as a negative regulator for sucrose metabolism. In addition, PpCBF1/5/6 were induced by EBR treatment and AtCBFs were upregulated in PpBZR1 transgenic Arabidopsis thaliana. Combined with previous findings, we hypothesize that PpBZR1 regulates PpVIN2 and may also be mediated by CBF. In conclusion, PpBZR1 expression is induced by EBR treatment during cold storage, which futher inhibite sucrose degradation gene PpVIN2 transcription via direct binding its promoter and indirectly regulating PpVIN2, resulting in slower sucrose degradation and higher chilling tolerance of peach.
PMID: 37611487
Plant Genome , IF:4.089 , 2023 Sep , V16 (3) : Pe20376 doi: 10.1002/tpg2.20376
Temporally gene knockout using heat shock-inducible genome-editing system in plants.
School of Life Science, Shanxi University, Taiyuan, Shanxi, China.; Research Institute of Big Data Science and Industry, Shanxi University, Taiyuan, Shanxi, China.
Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) has emerged as a powerful tool to generate targeted loss-of-function mutations for functional genomic studies. As a next step, tools to generate genome modifications in a spatially and temporally precise manner will enable researchers to further dissect gene function. Here, we present two heat shock-inducible genome-editing (IGE) systems that efficiently edit target genes when the system is induced, thus allowing us to target specific developmental stages. For this conditional editing system, we chose the natural heat-inducible promoter from heat-shock protein 18.2 (HSP18.2) from Arabidopsis thaliana and the synthetic heat-inducible promoter heat shock-response element HSE-COR15A to drive the expression of Cas9. We tested these two IGE systems in Arabidopsis using cyclic or continuous heat-shock treatments at the seedling and bolting stages. A real-time quantitative polymerase chain reaction analysis revealed that the HSP18.2 IGE system exhibited higher Cas9 expression levels than the HSE-COR15A IGE system upon both cyclic and continuous treatments. By targeting brassinosteroid-insensitive 1 (BRI1) and phytoene desaturase (PDS), we demonstrate that both cyclic and continuous heat inductions successfully activated the HSP18.2 IGE system at the two developmental stages, resulting in highly efficient targeted mutagenesis and clear phenotypic outcomes. By contrast, the HSE-COR15A IGE system was only induced at the seedling stage and was less effective than the HSP18.2 IGE system in terms of mutagenesis frequencies. The presented heat shock-IGE systems can be conditionally induced to efficiently inactivate genes at any developmental stage and are uniquely suited for the dissection and systematic characterization of essential genes.
PMID: 37529831
BMC Genomics , IF:3.969 , 2023 Sep , V24 (1) : P526 doi: 10.1186/s12864-023-09609-6
Integration of miRNA dynamics and drought tolerant QTLs in rice reveals the role of miR2919 in drought stress response.
ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India.; PG School, Indian Agricultural Research Institute, Pusa Campus New Delhi, New Delhi, 110012, India.; Division of Plant Physiology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; ICAR-Indian Agricultural Statistics Research Institute, New Delhi, 110012, India.; ICAR-National Institute for Plant Biotechnology, New Delhi, 110012, India. amitha.sevanthi@icar.gov.in.
To combat drought stress in rice, a major threat to global food security, three major quantitative trait loci for 'yield under drought stress' (qDTYs) were successfully exploited in the last decade. However, their molecular basis still remains unknown. To understand the role of secondary regulation by miRNA in drought stress response and their relation, if any, with the three qDTYs, the miRNA dynamics under drought stress was studied at booting stage in two drought tolerant (Sahbaghi Dhan and Vandana) and one drought sensitive (IR 20) cultivars. In total, 53 known and 40 novel differentially expressed (DE) miRNAs were identified. The primary drought responsive miRNAs were Osa-MIR2919, Osa-MIR3979, Osa-MIR159f, Osa-MIR156k, Osa-MIR528, Osa-MIR530, Osa-MIR2091, Osa-MIR531a, Osa-MIR531b as well as three novel ones. Sixty-one target genes that corresponded to 11 known and 4 novel DE miRNAs were found to be co-localized with the three qDTYs, out of the 1746 target genes identified. We could validate miRNA-mRNA expression under drought for nine known and three novel miRNAs in eight different rice genotypes showing varying degree of tolerance. From our study, Osa-MIR2919, Osa-MIR3979, Osa-MIR528, Osa-MIR2091-5p and Chr01_11911S14Astr and their target genes LOC_Os01g72000, LOC_Os01g66890, LOC_Os01g57990, LOC_Os01g56780, LOC_Os01g72834, LOC_Os01g61880 and LOC_Os01g72780 were identified as the most promising candidates for drought tolerance at booting stage. Of these, Osa-MIR2919 with 19 target genes in the qDTYs is being reported for the first time. It acts as a negative regulator of drought stress tolerance by modulating the cytokinin and brassinosteroid signalling pathway.
PMID: 37674140
Biochem Biophys Res Commun , IF:3.575 , 2023 Oct , V678 : P17-23 doi: 10.1016/j.bbrc.2023.08.031
BRASSINOSTEROID-INSENSITIVE 2 regulates salt stress tolerance in Arabidopsis by promoting AGL16 activity.
College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, 467036, Henan, China; Center of Healthy Food Engineering and Technology of Henan, Henan University of Urban Construction, Pingdingshan, 467036, Henan, China.; Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi, 830046, China. Electronic address: feixiao@xju.edu.cn.; College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, 467036, Henan, China; Center of Healthy Food Engineering and Technology of Henan, Henan University of Urban Construction, Pingdingshan, 467036, Henan, China. Electronic address: ltt198906@163.com.
Salt stress is a negative environmental factors to affecting plants. Salinity inhibits seed germination and root growth, which reduces the biomass of agricultural plants. BRASSINOSTEROID-INSENSITIVE2 (BIN2) functions as a signalling hub to integrate the perception and transduction of plant growth and stress tolerance by the phosphorylation of target proteins. However, only a small number of target molecules have been discovered thus far. In this study, we present evidence that BIN2 controls the post-transcriptional activity of AGL16. BIN2 interacts and phosphorylates AGL16, which increases AGL16 stability and transcriptional activity. Genetic testing showed that the agl16 mutant can restore the reduction in the seed germination rate and primary root growth of the bin2-1 mutant, while the overexpression of AGL16 in the bin2-3bil1bil2 mutant reduced the salt tolerance compared with bin2-3bil1bil2 in response to salt stress. Taken together, our data identify a BIN2-AGL16 core protein module that is mediates the inhibition of seed germination and primary root growth under salt stress.
PMID: 37611348
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2229957 doi: 10.1080/15592324.2023.2229957
The RGI1-BAK1 module acts as the main receptor-coreceptor pair for regulating primary root gravitropism and meristem activity in response to RGF1 peptide in Arabidopsis.
Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, Korea.; Kumho Life Science Laboratory, Chonnam National University, Gwangju, Korea.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Korea.
ROOT MERISTEM GROWTH FACTOR1 (RGF1) and its receptors RGF1 INSENSITIVEs (RGIs), a group of leucine-rich repeat receptor kinases, promote primary root meristem activity via a mitogen-activated protein kinase (MPK) signaling cascade and control root gravitropism in Arabidopsis. Genetic analyses and in vitro binding assays have indicated that among five RGIs identified in Arabidopsis, RGI1, RGI2, and RGI3 recognize RGF1 peptides. However, it remains unclear whether the RGF1 peptide is redundantly recognized by these RGIs or mainly by a single RGI in the regulation of primary root meristem activity. In the present study, we analyzed root meristem growth of the rgi1, rgi2, and rgi3 single mutants in response to RGF1 treatment and observed a significantly decreased sensitivity in meristem growth of rgi1 and complete insensitivity in rgi1 rgi2 rgi3 triple mutant compared with the wild type but not in the rgi1 and rgi2 single mutants. We also observed that both root gravitropism and meristem growth in the BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE 1 (bak1) single mutant were insensitive to RGF1 peptide treatment, whereas other serk mutants, such as serk1, serk2, and serk4, were fully sensitive to RGF1 peptide like the wild type. These mutant analyses suggest that RGI1-BAK1 pair acts as the main receptor-coreceptor pair for regulating primary root gravitropism and meristem activity in response to RGF1 peptide in Arabidopsis.
PMID: 37382066
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2186640 doi: 10.1080/15592324.2023.2186640
Exogenous Brassinosteroid Enhances Zinc tolerance by activating the Phenylpropanoid Biosynthesis pathway in Citrullus lanatus L.
College of Resources and Environmental Engineering, Yangzhou Polytechnic College, Yangzhou, China.; Jiangsu Safety & Environment Technology and Equipment for Planting and Breeding Industry Engineering Research Center, Yangzhou, China.
Zinc (Zn) is an important element in plants, but over-accumulation of Zn is harmful. The phytohormone brassinosteroids (BRs) play a key role in regulating plant growth, development, and response to stress. However, the role of BRs in watermelon (Citrullus lanatus L.) under Zn stress, one of the most important horticultural crops, remains largely unknown. In this study, we revealed that 24-epibrassinolide (EBR), a bioactive BR enhanced Zn tolerance in watermelon plants, which was related to the EBR-induced increase in the fresh weight, chlorophyll content, and net photosynthetic rate (Pn) and decrease in the content of hydrogen peroxide (H(2)O(2)), malondialdehyde (MDA), and Zn in watermelon leaves. Through RNA deep sequencing (RNA-seq), 350 different expressed genes (DEG) were found to be involved in the response to Zn stress after EBR treatment, including 175 up-regulated DEGs and 175 down-regulated DEGs. The up-regulated DEGs were significantly enriched in 'phenylpropanoid biosynthesis' pathway (map00940) using KEGG enrichment analysis. The gene expression levels of PAL, 4CL, CCR, and CCoAOMT, key genes involved in phenylpropanoid pathway, were significantly induced after EBR treatment. In addition, compared with Zn stress alone, EBR treatment significantly promoted the activities of PAL, 4CL, and POD by 30.90%, 20.69%, and 47.28%, respectively, and increased the content of total phenolic compounds, total flavonoids, and lignin by 23.02%, 40.37%, and 29.26%, respectively. The present research indicates that EBR plays an active role in strengthening Zn tolerance, thus providing new insights into the mechanism of BRs enhancing heavy metal tolerance.
PMID: 37083111
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163337 doi: 10.1080/15592324.2022.2163337
Arabidopsis clathrin adaptor EPSIN1 but not MODIFIED TRANSPORT TO THE VACOULE1 contributes to effective plant immunity against pathogenic Pseudomonas bacteria.
University of Missouri-Columbia, Division of Biochemistry, Interdisciplinary Plant Group (IPG), Columbia, MO, USA.; Department of Plant Physiology, University of Potsdam, Potsdam, Germany.
In eukaryotes, EPSINs are Epsin N-terminal Homology (ENTH) domain-containing proteins that serve as monomeric clathrin adaptors at the plasma membrane (PM) or the trans-Golgi Network (TGN)/early endosomes (EE). The model plant Arabidopsis thaliana encodes for seven ENTH proteins, of which so far, only AtEPSIN1 (AtEPS1) and MODIFIED TRANSPORT TO THE VACUOLE1 (AtMTV1) localize to the TGN/EE and contribute to cargo trafficking to both the cell surface and the vacuole. However, relatively little is known about role(s) of any plant EPSIN in governing physiological responses. We have recently shown that AtEPS1 is a positive modulator of plant immune signaling and pattern-triggered immunity against flagellated Pseudomonas syringae pv. tomato (Pto) DC3000 bacteria. In eps1 mutants, impaired immune responses correlate with reduced accumulation of the receptor FLAGELLIN SENSING2 (AtFLS2) and the convergent immune co-receptor BRASSINOSTEROID INSENTIVE1-ASSOCIATED RECEPTOR KINASE1 (AtBAK1) in the PM. Here, we report that in contrast to AtEPS1, the TGN/EE-localized AtMTV1 did not contribute significantly to immunity against pathogenic Pto DC3000 bacteria. We also compared the amino acid sequences, peptide motif structures and in silico tertiary structures of the ENTH domains of AtEPS1 and AtMTV1 in more detail. We conclude that despite sharing the classical tertiary alpha helical ENTH-domain structure and clathrin-binding motifs, the overall low amino acid identity and differences in peptide motifs may explain their role(s) in trafficking of some of the same as well as distinct cargo components to their site of function, with the latter potentially contributing to differences in physiological responses.
PMID: 36603596
Genes Genet Syst , IF:1.517 , 2023 Sep , V98 (2) : P89-92 doi: 10.1266/ggs.23-00029
Comprehensive analysis of downstream transcriptomic features in the competitive relationships between BEH3 and other BES/BZR transcription factors.
College of Life Sciences, Ritsumeikan University.; Graduate School of Science, Kobe University.
Members of a plant-specific BES/BZR transcription factor (TF) family including BRI1-EMS-SUPPRESSOR 1 (BES1) and BRASSINAZOLE-RESISTANT 1 (BZR1) regulate various developmental processes and environmental responses. Recently, we reported that BES1/BZR1 Homolog 3 (BEH3) exhibited a competitive effect toward other BES/BZR TFs. In this study, we analyzed transcriptome profiles in BEH3-overexpressing plants and compared them with those of BES1 and BZR1 double gain-of-function mutants. We identified 46 differentially expressed genes (DEGs), which were downregulated in the gain-of-function mutants of BES1 and BZR1 but upregulated upon BEH3 overexpression. In these DEGs, putative BES1 and BZR1 direct-targeted genes were highly enriched. In addition, these DEGs contained not only known brassinosteroid biosynthetic enzymes, but also some NAC TFs, which negatively regulate brassinosteroid-inactivating enzymes. Moreover, the iron sensor and the iron-deficient response-related bHLH TFs were also included. Taken together, our findings indicate that a competitive relationship between BEH3 and other BES/BZR TFs exists in various BES/BZR binding target genes.
PMID: 37331806
Stress Biol , 2023 Sep , V3 (1) : P42 doi: 10.1007/s44154-023-00124-y
BAK-up: the receptor kinase BAK-TO-LIFE 2 enhances immunity when BAK1 is lacking.
ZMBP, University Tubingen, Auf der Morgenstelle 32, Tubingen, 72076, Germany.; ZMBP, University Tubingen, Auf der Morgenstelle 32, Tubingen, 72076, Germany. birgit.kemmerling@zmbp.uni-tuebingen.de.
BRI1-ASSOCIATED KINASE 1 (BAK1/SERK3) and its closest homolog BAK1-LIKE 1 (BKK1/SERK4) are leucine-rich repeat receptor kinases (LRR-RKs) belonging to the SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK) family. They act as co-receptors of various other LRR-RKs and participate in multiple signaling events by complexing and transphosphorylating ligand-binding receptors. Initially identified as the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) co-receptor, BAK1 also functions in plant immunity by interacting with pattern recognition receptors. Mutations in BAK1 and BKK1 cause severely stunted growth and cell death, characterized as autoimmune cell death. Several factors play a role in this type of cell death, including RKs and components of effector-triggered immunity (ETI) signaling pathways, glycosylation factors, ER quality control components, nuclear trafficking components, ion channels, and Nod-like receptors (NLRs). The Shan lab has recently discovered a novel RK BAK-TO-LIFE 2 (BTL2) that interacts with BAK1 and triggers cell death in the absence of BAK1 and BKK1. This RK compensates for the loss of BAK1-mediated pattern-triggered immunity (PTI) by activating phytocytokine-mediated immune and cell death responses.
PMID: 37747566
Plant Commun , 2023 Sep , V4 (5) : P100604 doi: 10.1016/j.xplc.2023.100604
The miR167-OsARF12 module regulates rice grain filling and grain size downstream of miR159.
Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China.; Joint Center for Single Cell Biology/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.; Department of Biotechnology, Sharda University, Greater Noida 201306, India.; Institute of Paulownia, Henan Agricultural University, Zhengzhou 450046, China.; Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.; Joint Center for Single Cell Biology/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: hwxue@sjtu.edu.cn.; Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China; College of Agriculture, Guizhou University, Guiyang 550025, China. Electronic address: qzzhaoh@126.com.; Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, Zhengzhou 450046, China; Key Laboratory of Rice Biology in Henan Province, Henan Agricultural University, Zhengzhou 450046, China; Henan Engineering Laboratory of Rice, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: lypengting@163.com.
Grain weight and quality are always determined by grain filling. Plant microRNAs have drawn attention as key targets for regulation of grain size and yield. However, the mechanisms that underlie grain size regulation remain largely unclear because of the complex networks that control this trait. Our earlier studies demonstrated that suppressed expression of miR167 (STTM/MIM167) substantially increased grain weight. In a field test, the yield increased up to 12.90%-21.94% because of a significantly enhanced grain filling rate. Here, biochemical and genetic analyses revealed the regulatory effects of miR159 on miR167 expression. Further analysis indicated that OsARF12 is the major mediator by which miR167 regulates rice grain filling. Overexpression of OsARF12 produced grain weight and grain filling phenotypes resembling those of STTM/MIM167 plants. Upon in-depth analysis, we found that OsARF12 activates OsCDKF;2 expression by directly binding to the TGTCGG motif in its promoter region. Flow cytometry analysis of young panicles from OsARF12-overexpressing plants and examination of cell number in cdkf;2 mutants verified that OsARF12 positively regulates grain filling and grain size by targeting OsCDKF;2. Moreover, RNA sequencing results suggested that the miR167-OsARF12 module is involved in the cell development process and hormone pathways. OsARF12-overexpressing plants and cdkf;2 mutants exhibited enhanced and reduced sensitivity to exogenous auxin and brassinosteroid (BR) treatment, confirming that targeting of OsCDKF;2 by OsARF12 mediates auxin and BR signaling. Our results reveal that the miR167-OsARF12 module works downstream of miR159 to regulate rice grain filling and grain size via OsCDKF;2 by controlling cell division and mediating auxin and BR signals.
PMID: 37085993