Trends Plant Sci , IF:18.313 , 2023 Aug doi: 10.1016/j.tplants.2023.07.010
Single cell RNA-seq in phytohormone signaling: a promising future.
College of Agriculture, South China Agriculture University, Guangzhou, Guangdong 510642, China.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia. Electronic address: rajeev.varshney@murdoch.edu.au.; Guangdong Provincial Key Laboratory of Crop Genetic Improvement, South China Peanut Sub-Center of National Center of Oilseed Crops Improvement, Crops Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510640, China. Electronic address: liuhao@gdaas.cn.
Phytohormone signaling regulates plant growth and development. Single cell RNA sequencing (scRNA-seq) provides unprecedented opportunities to decipher hormone-mediated spatiotemporal gene regulatory networks. In a recent study, Nolan et al. used time-series scRNA-seq to identify the cortex as a key site for brassinosteroid (BR)-mediated gene expression and revealed a signaling network during cell phase transition.
PMID: 37550122
Dev Cell , IF:12.27 , 2023 Aug 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 Aug , V35 (8) : P2871-2886 doi: 10.1093/plcell/koad130
The transcriptional hub SHORT INTERNODES1 integrates hormone signals to orchestrate rice growth and development.
State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plants have evolved sophisticated mechanisms to coordinate their growth and stress responses via integrating various phytohormone signaling pathways. However, the precise molecular mechanisms orchestrating integration of the phytohormone signaling pathways remain largely obscure. In this study, we found that the rice (Oryza sativa) short internodes1 (shi1) mutant exhibits typical auxin-deficient root development and gravitropic response, brassinosteroid (BR)-deficient plant architecture and grain size as well as enhanced abscisic acid (ABA)-mediated drought tolerance. Additionally, we found that the shi1 mutant is also hyposensitive to auxin and BR treatment but hypersensitive to ABA. Further, we showed that OsSHI1 promotes the biosynthesis of auxin and BR by activating the expression of OsYUCCAs and D11, meanwhile dampens ABA signaling by inducing the expression of OsNAC2, which encodes a repressor of ABA signaling. Furthermore, we demonstrated that 3 classes of transcription factors, AUXIN RESPONSE FACTOR 19 (OsARF19), LEAF AND TILLER ANGLE INCREASED CONTROLLER (LIC), and OsZIP26 and OsZIP86, directly bind to the promoter of OsSHI1 and regulate its expression in response to auxin, BR, and ABA, respectively. Collectively, our results unravel an OsSHI1-centered transcriptional regulatory hub that orchestrates the integration and self-feedback regulation of multiple phytohormone signaling pathways to coordinate plant growth and stress adaptation.
PMID: 37195873
New Phytol , IF:10.151 , 2023 Aug doi: 10.1111/nph.19204
OsbHLH92, in the noncanonical brassinosteroid signaling pathway, positively regulates leaf angle and grain weight in rice.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; College of Bioscience and Bioengineering, Hebei University of Science and Technology, Hebei, 050000, China.
Modifications of plant architecture can increase planting density, regulate photosynthesis, and improve crop yields. Many basic helix-loop-helix (bHLH) transcription factors participate in the brassinosteroid (BR) signaling pathway and are critical for plant architecture morphogenesis in rice. However, the number of identified bHLH genes suitable for improving production value is still limited. In this study, we cloned Lam1, encoding the typical bHLH transcription factor OsbHLH92. OsbHLH92 knockout (KO) lines exhibit erect leaves. Decreases in the number and size of parenchyma cell layers on the adaxial side of the lamina joint in KO lines were the main reason for the decreased leaf angle. Genetic experiments verify that OsBU1 and its homologs are downstream of OsbHLH92, which is involved in the noncanonical RGA1-mediated BR signaling pathway. OsbHLH91, an OsbHLH92 homolog, plays both conserved and differentiated roles relative to OsbHLH92. Notably, OsbHLH92-KO lines show erect leaves without the acquisition of adverse agronomic traits. Moreover, by driving a specific panicle promoter, OsbHLH92 can greatly increase productivity by at least 10%. This study identifies new components of the BR signaling pathway, demonstrates the importance of OsbHLH92 in improving planting density and crop productivity, and broadens our knowledge of typical and atypical bHLH family members in rice.
PMID: 37574840
New Phytol , IF:10.151 , 2023 Aug , V239 (4) : P1368-1383 doi: 10.1111/nph.19007
Phosphate deprivation-induced changes in tomato are mediated by an interaction between brassinosteroid signaling and zinc.
Department of Plant Biology and Genome Center, University of California Davis, Davis, CA, 95616, USA.; Department of Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.; Department of Horticulture, Zhejiang University, Hangzhou, Zhejiang, 310058, China.; Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel.; Lorey I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Palacky University, Olomouc, CZ-78371, Czech Republic.
Inorganic phosphate (Pi) is a necessary macronutrient for basic biological processes. Plants modulate their root system architecture (RSA) and cellular processes to adapt to Pi deprivation albeit with a growth penalty. Excess application of Pi fertilizer, on the contrary, leads to eutrophication and has a negative environmental impact. We compared RSA, root hair elongation, acid phosphatase activity, metal ion accumulation, and brassinosteroid hormone levels of Solanum lycopersicum (tomato) and Solanum pennellii, which is a wild relative of tomato, under Pi sufficiency and deficiency conditions to understand the molecular mechanism of Pi deprivation response in tomato. We showed that S. pennellii is partially insensitive to phosphate deprivation. Furthermore, it mounts a constitutive response under phosphate sufficiency. We demonstrate that activated brassinosteroid signaling through a tomato BZR1 ortholog gives rise to the same constitutive phosphate deficiency response, which is dependent on zinc overaccumulation. Collectively, these results reveal an additional strategy by which plants can adapt to phosphate starvation.
PMID: 37306070
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
J Integr Plant Biol , IF:7.061 , 2023 Aug doi: 10.1111/jipb.13554
The advantages of crosstalk during the evolution of the BZR1-ARF6-PIF4 (BAP) module.
College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
The BAP module, comprising BRASSINAZOLE RESISTANT 1 (BZR1), AUXIN RESPONSE FACTOR 6 (ARF6), and PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), functions as a molecular hub to orchestrate plant growth and development. In Arabidopsis thaliana, components of the BAP module physically interact to form a complex system that integrates light, brassinosteroid (BR), and auxin signals. Little is known about the origin and evolution of the BAP module. Here, we conducted comparative genomic and transcriptomic analyses to investigate the evolution and functional diversification of the BAP module. Our results suggest that the BAP module originated in land plants and that the zeta, epsilon, and gamma whole-genome duplication/triplication events contributed to the expansion of BAP module components in seed plants. Comparative transcriptomic analysis suggested that the prototype BAP module arose in Marchantia polymorpha, experienced stepwise evolution, and became established as a mature regulatory system in seed plants. We developed a formula to calculate the signal transduction productivity of the BAP module and demonstrate that more crosstalk among components enables higher signal transduction efficiency. Our results reveal the evolutionary history of the BAP module and provide insights into the evolution of plant signaling networks and the strategies employed by plants to integrate environmental and endogenous signals. This article is protected by copyright. All rights reserved.
PMID: 37552560
J Integr Plant Biol , IF:7.061 , 2023 Aug , V65 (8) : P1852-1858 doi: 10.1111/jipb.13509
Fine-tuning brassinosteroid biosynthesis via 3'UTR-dependent decay of CPD mRNA modulates wood formation in Populus.
College of Agronomy, Qingdao Agricultural University, Qingdao, 266109, China.; College of Resources and Environment, Qingdao Agricultural University, Qingdao, 266109, China.; College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, 266109, China.; State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, 311300, China.
Brassinosteroids (BRs) are plant hormones that regulate wood formation in trees. Currently, little is known about the post-transcriptional regulation of BR synthesis. Here, we show that during wood formation, fine-tuning BR synthesis requires 3'UTR-dependent decay of Populus CONSTITUTIVE PHOTOMORPHOGENIC DWARF 1 (PdCPD1). Overexpression of PdCPD1 or its 3' UTR fragment resulted in a significant increase of BR levels and inhibited secondary growth. In contrast, transgenic poplars repressing PdCPD1 3' UTR expression displayed moderate levels of BR and promoted wood formation. We show that the Populus GLYCINE-RICH RNA-BINDING PROTEIN 1 (PdGRP1) directly binds to a GU-rich element in 3' UTR of PdCPD1, leading to its mRNA decay. We thus provide a post-transcriptional mechanism underlying BRs synthesis during wood formation, which may be useful for genetic manipulation of wood biomass in trees.
PMID: 37203882
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (15) doi: 10.3390/ijms241512255
Distinct Clades of Protein Phosphatase 2A Regulatory B'/B56 Subunits Engage in Different Physiological Processes.
IKBM, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway.
Protein phosphatase 2A (PP2A) is a strongly conserved and major protein phosphatase in all eukaryotes. The canonical PP2A complex consists of a catalytic (C), scaffolding (A), and regulatory (B) subunit. Plants have three groups of evolutionary distinct B subunits: B55, B' (B56), and B''. Here, the Arabidopsis B' group is reviewed and compared with other eukaryotes. Members of the B'alpha/B'beta clade are especially important for chromatid cohesion, and dephosphorylation of transcription factors that mediate brassinosteroid (BR) signaling in the nucleus. Other B' subunits interact with proteins at the cell membrane to dampen BR signaling or harness immune responses. The transition from vegetative to reproductive phase is influenced differentially by distinct B' subunits; B'alpha and B'beta being of little importance, whereas others (B'gamma, B'zeta, B'eta, B'theta, B'kappa) promote transition to flowering. Interestingly, the latter B' subunits have three motifs in a conserved manner, i.e., two docking sites for protein phosphatase 1 (PP1), and a POLO consensus phosphorylation site between these motifs. This supports the view that a conserved PP1-PP2A dephosphorelay is important in a variety of signaling contexts throughout eukaryotes. A profound understanding of these regulators may help in designing future crops and understand environmental issues.
PMID: 37569631
Front Plant Sci , IF:5.753 , 2023 , V14 : P1219856 doi: 10.3389/fpls.2023.1219856
BRI1 EMS SUPPRESSOR1 genes regulate abiotic stress and anther development in wheat (Triticum aestivum L.).
Institute of Hybrid Wheat, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.; The Municipal Key Laboratory of the Molecular Genetics of Hybrid Wheat, Hubei Collaborative Innovation Center for Grain Industry, Beijing, China.; Agriculture College, Yangtze University, Jingzhou, China.
BRI1 EMS SUPPRESSOR1 (BES1) family members are crucial downstream regulators that positively mediate brassinosteroid signaling, playing vital roles in the regulation of plant stress responses and anther development in Arabidopsis. Importantly, the expression profiles of wheat (Triticum aestivum L.) BES1 genes have not been analyzed comprehensively and systematically in response to abiotic stress or during anther development. In this study, we identified 23 BES1-like genes in common wheat, which were unevenly distributed on 17 out of 21 wheat chromosomes. Phylogenetic analysis clustered the BES1 genes into four major clades; moreover, TaBES1-3A2, TaBES1-3B2 and TaBES1-3D2 belonged to the same clade as Arabidopsis BES1/BZR1 HOMOLOG3 (BEH3) and BEH4, which participate in anther development. The expression levels of 23 wheat BES1 genes were assessed using real-time quantitative PCR under various abiotic stress conditions (drought, salt, heat, and cold), and we found that most TaBES1-like genes were downregulated under abiotic stress, particularly during drought stress. We therefore used drought-tolerant and drought-sensitive wheat cultivars to explore TaBES1 expression patterns under drought stress. TaBES1-3B2 and TaBES1-3D2 expression was high in drought-tolerant cultivars but substantially repressed in drought-sensitive cultivars, while TaBES1-6D presented an opposite pattern. Among genes preferentially expressed in anthers, TaBES1-3B2 and TaBES1-3D2 expression was substantially downregulated in thermosensitive genic male-sterile wheat lines compared to common wheat cultivar under sterile conditions, while we detected no obvious differences under fertile conditions. This result suggests that TaBES1-3B2 and TaBES1-3D2 might not only play roles in regulating drought tolerance, but also participate in low temperature-induced male sterility.
PMID: 37621887
Front Plant Sci , IF:5.753 , 2023 , V14 : P1239917 doi: 10.3389/fpls.2023.1239917
Uncovering transcriptional reprogramming during callus development in soybean: insights and implications.
Department of Applied Bioscience, Dong-A University, Busan, Republic of Korea.; Department of Molecular Genetics, Dong-A University, Busan, Republic of Korea.
Callus, a valuable tool in plant genetic engineering, originates from dedifferentiated cells. While transcriptional reprogramming during callus formation has been extensively studied in Arabidopsis thaliana, our knowledge of this process in other species, such as Glycine max, remains limited. To bridge this gap, our study focused on conducting a time-series transcriptome analysis of soybean callus cultured for various durations (0, 1, 7, 14, 28, and 42 days) on a callus induction medium following wounding with the attempt of identifying genes that play key roles during callus formation. As the result, we detected a total of 27,639 alterations in gene expression during callus formation, which could be categorized into eight distinct clusters. Gene ontology analysis revealed that genes associated with hormones, cell wall modification, and cell cycle underwent transcriptional reprogramming throughout callus formation. Furthermore, by scrutinizing the expression patterns of genes related to hormones, cell cycle, cell wall, and transcription factors, we discovered that auxin, cytokinin, and brassinosteroid signaling pathways activate genes involved in both root and shoot meristem development during callus formation. In summary, our transcriptome analysis provides significant insights into the molecular mechanisms governing callus formation in soybean. The information obtained from this study contributes to a deeper understanding of this intricate process and paves the way for further investigation in the field.
PMID: 37600197
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 Aug , 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 Aug : 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
Biochem Biophys Res Commun , IF:3.575 , 2023 Aug , 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
J Plant Physiol , IF:3.549 , 2023 Aug , V287 : P154052 doi: 10.1016/j.jplph.2023.154052
Uncovering mechanisms governing stem growth in peanut (Arachis hypogaea L.) with varying plant heights through integrated transcriptome and metabolomics analyses.
College of Agronomy, Shandong Agricultural University, Tai'an, 271018, Shandong, China.; Industrial Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China. Electronic address: liujuanviolet@163.com.; College of Agronomy, Shandong Agricultural University, Tai'an, 271018, Shandong, China. Electronic address: chengyang2364@126.com.
The mechanisms responsible for stem growth in peanut (Arachis hypogaea L.) cultivars with varying plant heights remain unclear, despite the significant impact of plant height on peanut yield. Therefore, this study aimed to investigate the underlying mechanisms of peanut stem growth using phenotypic, physiological, transcriptomic, and metabolomic analyses. The findings revealed that the tallest cultivar, HY33, exhibited the highest rate of stem growth and accumulated the most stem dry matter, followed by the intermediate cultivar, SH108, while the dwarf cultivar, Df216, displayed the lowest values. Furthermore, SH108 exhibited a higher harvest index, as well as superior pod and kernel yields compared to both HY33 and Df216. Transcriptome and metabolome analyses identified differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) associated with phenylpropanoid and flavonoid biosynthesis. Notably, downregulated DEGs in Df216/HY33 and Df216/SH108 included phenylalanine ammonia-lyase (PAL), caffeoyl-CoA O-methyltransferase (COMT), and ferulate-5-hydroxylase (F5H), while downregulated DEMs included p-coumaryl alcohol, chlorogenic acid, and L-epicatechin. Compared to HY33, the reduced activities of PAL, COMT, and F5H resulted in a decreased stem lignin content in Df216. Additionally, downregulated DEGs involved in gibberellin (GA) and brassinosteroid (BR) biosynthesis were identified in Df216/HY33, which contributed to the lowest levels of GA(1), GA(3), and BR contents in Df216. The results suggest that the dwarf phenotype arises from impaired GA and BR biosynthesis and signaling, resulting in a slower stem growth rate and reduced lignin accumulation.
PMID: 37454530
Plant Direct , IF:3.038 , 2023 Aug , V7 (8) : Pe524 doi: 10.1002/pld3.524
The brassinosteroid-responsive protein OCTOPUS is a novel regulator of Arabidopsis thaliana immune signaling.
Department of Chemistry and Physics Drury University Springfield Missouri USA.; Present address: DaVita Dialysis Overland Park Kansas USA.; Present address: Department of Chemistry and Biochemistry University of Notre Dame South Bend Indiana USA.; Present address: School of Medicine Washington University in St. Louis St. Louis Missouri USA.; Department of Biology Marian University Indianapolis Indiana USA.; Present address: Krannert School of Physical Therapy University of Indianapolis Indianapolis Indiana USA.; Present address: Department of Biological Sciences Butler University Indianapolis Indiana USA.; Present address: Eli Lilly and Company Lilly Corporate Center Indianapolis Indiana USA.
Phloem is a critical tissue for transport of photosynthates and extracellular signals in vascular plants. However, it also represents an ideal environment for pathogens seeking access to valuable host nutrients. Although many vascular pathogens induce economically relevant crop damage, there is still little known about the mechanisms by which immune signaling operates through the phloem. An existing phosphoproteomic dataset was mined to identify proteins that were both phosphorylated in response to the defense-elicitor flagellin (flg22) and expressed in vascular cells. A single candidate, OCTOPUS (OPS), is polarly associated with the plasma membrane of sieve element cells and has been characterized as an inhibitor of brassinosteroid insensitive-2 in promotion of brassinosteroid-related phytohormone signaling. The observation that OPS is differentially phosphorylated in response to flg22 led us to the examine whether OPS may also regulate flg22-induced immune signaling. Two independent alleles of ops exhibited enhanced immunity outputs across multiple signaling branches of PAMP-triggered immunity (PTI), constitutively and in response to flg22 treatment. Together with our observation that interactions between OPS and brassinosteroid insensitive-2 were disrupted by induction of salicylic acid and depletion of brassinosteriod, these data support a model whereby OPS modulates brassinolide and immune signaling to control downstream responses. We present OPS as a novel addition to the list of proteins with documented roles in PAMP-PTI signaling. These results further indicate that immune signaling in the phloem may be a significant and unique component of the host detection and response to pathogens in vascular plants.
PMID: 37638229
Steroids , IF:2.668 , 2023 Aug , V196 : P109248 doi: 10.1016/j.steroids.2023.109248
Methyl esters of 23,24-Dinor-5alpha-cholan-22-oic acids as brassinosteroid Analogues. Synthesis, evaluation of plant growth promoting activity and Molecular docking.
Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Av. Espana No. 1680, Valparaiso 2340000, Chile.; Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico D.F., Mexico, United States.; Departamento de Quimica Organica, Instituto Universitario de Bio-Organica Antonio Gonzalez, Universidad de La Laguna, Av. Astrofisico Fco. Sanchez 2, 38206 La Laguna, Spain.; Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Av. Espana No. 1680, Valparaiso 2340000, Chile. Electronic address: luis.espinozac@usm.cl.; Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico D.F., Mexico, United States. Electronic address: martin.iglesias@unam.mx.
Five new brassinosteroid analogues were synthetized from 3beta-acetoxy-23,24-dinorchol-4-en-22-oic acid. All the obtained compound showed significant activity in the Rice Lamina Inclination Test. Interestingly the effects of the methyl ester of 3beta-hydroxy-6-oxo-23,24-dinorcholan-22-oic acid (14) at concentrations of 1 x 10(-7) and 1 x 10(-6) M proved to be higher than those produced by brassinolide. In silico Molecular Docking and Induced fit docking (IFD) simulations for the compounds with the highest biological activity data were carried out to investigate the binding mode interactions into the brassinolide-binding groove which revealed that the compound 14 had high binding energy values and a good affinity.
PMID: 37169217
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
J Genet Genomics , 2023 Aug , V50 (8) : P541-553 doi: 10.1016/j.jgg.2023.03.004
Brassinosteroid signaling and molecular crosstalk with nutrients in plants.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China.; The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong 266237, China. Electronic address: baimingyi@sdu.edu.cn.
As sessile organisms, plants have evolved sophisticated mechanisms to optimize their growth and development in response to fluctuating nutrient levels. Brassinosteroids (BRs) are a group of plant steroid hormones that play critical roles in plant growth and developmental processes as well as plant responses to environmental stimuli. Recently, multiple molecular mechanisms have been proposed to explain the integration of BRs with different nutrient signaling processes to coordinate gene expression, metabolism, growth, and survival. Here, we review recent advances in understanding the molecular regulatory mechanisms of the BR signaling pathway and the multifaceted roles of BR in the intertwined sensing, signaling, and metabolic processes of sugar, nitrogen, phosphorus, and iron. Further understanding and exploring these BR-related processes and mechanisms will facilitate advances in crop breeding for higher resource efficiency.
PMID: 36914050