Ruonan Li, Yue Xu, Qiang Xu, Jing Tang, Wenqing Chen, Zhixiang Luo, Hongbo Liu, Wenqiang Li, Jianbing Yan, Nathan M Springer, Lin Li, Qing Li
Plant architecture greatly contributes to grain yield, but the epigenetic regulation of plant architecture remains elusive. Here, we identified the maize (Zea mays L.) mutant plant architecture 1 (par1), which shows reduced plant height, shorter and narrower leaves, and larger leaf angles than the wild type. Interestingly, par1 is an epiallele harboring a de novo CACTA insertion in the intron of the Par1 gene. High DNA methylation levels of the CACTA insertion are associated with strong Par1 expression and normal phenotypes. In contrast, low DNA methylation levels of this insertion are associated with weak Par1 expression and a mutant-like phenotype. The Par1 gene encodes a PfkB-type carbohydrate kinase that converts nucleosides to nucleoside monophosphates both in vitro and in vivo. Additional analyses showed that genes differentially expressed in the par1 mutant are enriched in jasmonic acid (JA) metabolism, and levels of JA metabolites were significantly higher in the mutant than in the wild type. Treatment with either nucleoside monophosphates or a synthetic inhibitor of JA biosynthesis reduced JA levels and partially rescued the mutant phenotype. In summary, we identified an epiallele of a gene encoding a PfkB-type carbohydrate kinase that might affect nucleoside monophosphate and JA levels, thus affecting maize growth.
{"title":"An epiallele of a gene encoding a PfkB-type carbohydrate kinase affects plant architecture in maize","authors":"Ruonan Li, Yue Xu, Qiang Xu, Jing Tang, Wenqing Chen, Zhixiang Luo, Hongbo Liu, Wenqiang Li, Jianbing Yan, Nathan M Springer, Lin Li, Qing Li","doi":"10.1093/plcell/koaf017","DOIUrl":"https://doi.org/10.1093/plcell/koaf017","url":null,"abstract":"Plant architecture greatly contributes to grain yield, but the epigenetic regulation of plant architecture remains elusive. Here, we identified the maize (Zea mays L.) mutant plant architecture 1 (par1), which shows reduced plant height, shorter and narrower leaves, and larger leaf angles than the wild type. Interestingly, par1 is an epiallele harboring a de novo CACTA insertion in the intron of the Par1 gene. High DNA methylation levels of the CACTA insertion are associated with strong Par1 expression and normal phenotypes. In contrast, low DNA methylation levels of this insertion are associated with weak Par1 expression and a mutant-like phenotype. The Par1 gene encodes a PfkB-type carbohydrate kinase that converts nucleosides to nucleoside monophosphates both in vitro and in vivo. Additional analyses showed that genes differentially expressed in the par1 mutant are enriched in jasmonic acid (JA) metabolism, and levels of JA metabolites were significantly higher in the mutant than in the wild type. Treatment with either nucleoside monophosphates or a synthetic inhibitor of JA biosynthesis reduced JA levels and partially rescued the mutant phenotype. In summary, we identified an epiallele of a gene encoding a PfkB-type carbohydrate kinase that might affect nucleoside monophosphate and JA levels, thus affecting maize growth.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photorespiration, often considered as a wasteful process, is a key target for bioengineering to improve crop yields. Several photorespiratory bypasses have been designed to efficiently metabolize 2-phosphoglycolate and increase the CO2 concentration in chloroplasts, thereby reducing photorespiration. However, the suppression of primary nitrate assimilation remains an issue when photorespiration is inhibited. In this study, we designed a carbon and nitrogen metabolism-coupled photorespiratory bypass, termed the GCBG bypass, in rice (Oryza sativa) chloroplasts. Our results demonstrated efficient assembly and expression of the GCBG bypass in rice chloroplasts, which affected the levels of typical metabolites and their derivatives of natural photorespiration and enhanced the photosynthetic efficiency. Metabolomic analyses revealed that oxaloacetate, produced from glycolate in chloroplasts, positively impacted amino acid synthesis, energy metabolism, and sugar synthesis. The engineered GCBG plants showed an average yield increase of 19.0% (17.8-20.2%) compared to wild-type plants under natural growth conditions, alongside improved nitrogen uptake, which compensated for 44.1% of yield losses under nitrogen-limited conditions. In summary, the GCBG bypass substantially improved the photosynthetic efficiency, biomass and yield in rice by integrating carbon and nitrogen metabolism. This study introduces a strategy for engineering high-yielding rice or other crops with improved photosynthetic efficiency and nitrogen uptake.
{"title":"Synthetic photorespiratory bypass improves rice productivity by enhancing photosynthesis and nitrogen uptake","authors":"Guoxin Chen, Yanni Li, Kaining Jin, Jiabei Gao, Suting Wu, Xuean Cui, Chuanzao Mao, Xinyou Yin, Tiegang Lu, Zhiguo Zhang","doi":"10.1093/plcell/koaf015","DOIUrl":"https://doi.org/10.1093/plcell/koaf015","url":null,"abstract":"Photorespiration, often considered as a wasteful process, is a key target for bioengineering to improve crop yields. Several photorespiratory bypasses have been designed to efficiently metabolize 2-phosphoglycolate and increase the CO2 concentration in chloroplasts, thereby reducing photorespiration. However, the suppression of primary nitrate assimilation remains an issue when photorespiration is inhibited. In this study, we designed a carbon and nitrogen metabolism-coupled photorespiratory bypass, termed the GCBG bypass, in rice (Oryza sativa) chloroplasts. Our results demonstrated efficient assembly and expression of the GCBG bypass in rice chloroplasts, which affected the levels of typical metabolites and their derivatives of natural photorespiration and enhanced the photosynthetic efficiency. Metabolomic analyses revealed that oxaloacetate, produced from glycolate in chloroplasts, positively impacted amino acid synthesis, energy metabolism, and sugar synthesis. The engineered GCBG plants showed an average yield increase of 19.0% (17.8-20.2%) compared to wild-type plants under natural growth conditions, alongside improved nitrogen uptake, which compensated for 44.1% of yield losses under nitrogen-limited conditions. In summary, the GCBG bypass substantially improved the photosynthetic efficiency, biomass and yield in rice by integrating carbon and nitrogen metabolism. This study introduces a strategy for engineering high-yielding rice or other crops with improved photosynthetic efficiency and nitrogen uptake.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142987460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Illuminating what lies in darkness: Circadian regulation of hypocotyl growth in Arabidopsis via ELF3 recruitment of demethylases.","authors":"Julie Robinson","doi":"10.1093/plcell/koaf018","DOIUrl":"https://doi.org/10.1093/plcell/koaf018","url":null,"abstract":"","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quan Sun, Zhengchen He, Ranran Wei, Junli Ye, Lijun Chai, Yunjiang Cheng, Qiang Xu, Xiuxin Deng
The reddish apocarotenoid β-citraurin, produced by CAROTENOID CLEAVAGE DIOXYGENASE 4b (CsCCD4b), is responsible for peel reddening in citrus (Citrus spp.). Ethylene induces the characteristic red color of citrus peel, but the underlying molecular mechanism remains largely unclear. Here, we identified Red peel regulator 1 (CsRP1), a trihelix transcriptional activator that regulates ethylene-induced peel reddening by directly binding to a key MYB-binding site in the CsCCD4b promoter, thus activating its transcription. Furthermore, two drought-responsive cis-elements in the CsRP1 promoter are bound by the ethylene-response factor Ethylene response factor 25 (CsERF25). We reconstructed the CsERF25–CsRP1–CsCCD4b transcriptional regulatory cascade through transient expression of CsERF25 and CsRP1 in citrus peel and via stable transformation of citrus calli. In this cascade, CsERF25 expression was induced by ethylene to activate CsRP1 expression, and then CsRP1 directly induced CsCCD4b transcription to catalyze β-citraurin biosynthesis. CsRP1 and CsERF25 also bound to the promoters of other carotenogenic genes and induced their transcription, thereby promoting β-citraurin accumulation. Collectively, our findings reveal a complex regulatory network modulating ethylene-induced citrus peel reddening and provide innovative strategies for improving the nutritional and aesthetic values of citrus and other fruit crops.
{"title":"Red peel regulator1 links Ethylene response factor 25 and β-citraurin biosynthetic genes to regulate ethylene-induced peel reddening in citrus","authors":"Quan Sun, Zhengchen He, Ranran Wei, Junli Ye, Lijun Chai, Yunjiang Cheng, Qiang Xu, Xiuxin Deng","doi":"10.1093/plcell/koaf010","DOIUrl":"https://doi.org/10.1093/plcell/koaf010","url":null,"abstract":"The reddish apocarotenoid β-citraurin, produced by CAROTENOID CLEAVAGE DIOXYGENASE 4b (CsCCD4b), is responsible for peel reddening in citrus (Citrus spp.). Ethylene induces the characteristic red color of citrus peel, but the underlying molecular mechanism remains largely unclear. Here, we identified Red peel regulator 1 (CsRP1), a trihelix transcriptional activator that regulates ethylene-induced peel reddening by directly binding to a key MYB-binding site in the CsCCD4b promoter, thus activating its transcription. Furthermore, two drought-responsive cis-elements in the CsRP1 promoter are bound by the ethylene-response factor Ethylene response factor 25 (CsERF25). We reconstructed the CsERF25–CsRP1–CsCCD4b transcriptional regulatory cascade through transient expression of CsERF25 and CsRP1 in citrus peel and via stable transformation of citrus calli. In this cascade, CsERF25 expression was induced by ethylene to activate CsRP1 expression, and then CsRP1 directly induced CsCCD4b transcription to catalyze β-citraurin biosynthesis. CsRP1 and CsERF25 also bound to the promoters of other carotenogenic genes and induced their transcription, thereby promoting β-citraurin accumulation. Collectively, our findings reveal a complex regulatory network modulating ethylene-induced citrus peel reddening and provide innovative strategies for improving the nutritional and aesthetic values of citrus and other fruit crops.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Salt stress causes ion toxicity in plant cells and limits plant growth and crop productivity. Sodium ions (Na+) are transported out of the cell and sequestered in the vacuole for detoxification under salt stress. The salt excretion system is controlled by the SALT OVERLY SENSITIVE (SOS) pathway, which consists of the calcium sensors SOS3 and SOS3-LIKE CALCIUM BINDING PROTEIN 8, the protein kinase SOS2, and the plasma membrane Na+/H+ antiporter SOS1. Although much is known about salt responses in plants at the molecular level, it remains unclear if and how plants respond to salt stress through endomembrane remodeling. In this study, we describe a mechanism of salt tolerance in Arabidopsis (Arabidopsis thaliana) involving the modulation of FREE1 levels, which impacts multivesicular body (MVB) trafficking. Specifically, the ESCRT-I (endosomal sorting complex required for transport-I) component FREE1 (FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1) regulates vacuole fragmentation to enhance salt tolerance. SOS2 phosphorylates FREE1, leading to its degradation and affecting MVB maturation, thereby reducing MVB-vacuole fusion and regulating endomembrane dynamics in response to salt stress. These findings highlight the adaptive role of the plant endomembrane system in coping with salt stress.
{"title":"SOS2 phosphorylates FREE1 to regulate multi-vesicular body trafficking and vacuolar dynamics under salt stress","authors":"Guoyong Liu, Yonglun Zeng, Baiying Li, Xiangfeng Wang, Liwen Jiang, Yan Guo","doi":"10.1093/plcell/koaf012","DOIUrl":"https://doi.org/10.1093/plcell/koaf012","url":null,"abstract":"Salt stress causes ion toxicity in plant cells and limits plant growth and crop productivity. Sodium ions (Na+) are transported out of the cell and sequestered in the vacuole for detoxification under salt stress. The salt excretion system is controlled by the SALT OVERLY SENSITIVE (SOS) pathway, which consists of the calcium sensors SOS3 and SOS3-LIKE CALCIUM BINDING PROTEIN 8, the protein kinase SOS2, and the plasma membrane Na+/H+ antiporter SOS1. Although much is known about salt responses in plants at the molecular level, it remains unclear if and how plants respond to salt stress through endomembrane remodeling. In this study, we describe a mechanism of salt tolerance in Arabidopsis (Arabidopsis thaliana) involving the modulation of FREE1 levels, which impacts multivesicular body (MVB) trafficking. Specifically, the ESCRT-I (endosomal sorting complex required for transport-I) component FREE1 (FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1) regulates vacuole fragmentation to enhance salt tolerance. SOS2 phosphorylates FREE1, leading to its degradation and affecting MVB maturation, thereby reducing MVB-vacuole fusion and regulating endomembrane dynamics in response to salt stress. These findings highlight the adaptive role of the plant endomembrane system in coping with salt stress.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michelle Gallei, Sven Truckenbrodt, Caroline Kreuzinger, Syamala Inumella, Vitali Vistunou, Christoph Sommer, Mojtaba R Tavakoli, Nathalie Agudelo Dueñas, Jakob Vorlaufer, Wiebke Jahr, Marek Randuch, Alexander Johnson, Eva Benková, Jiří Friml, Johann G Danzl
Super-resolution methods provide far better spatial resolution than the optical diffraction limit of about half the wavelength of light (∼200-300 nm). Nevertheless, they have yet to attain widespread use in plants, largely due to plants’ challenging optical properties. Expansion microscopy improves effective resolution by isotropically increasing the physical distances between sample structures while preserving relative spatial arrangements and clearing the sample. However, its application to plants has been hindered by the rigid, mechanically cohesive structure of plant tissues. Here, we report on whole-mount expansion microscopy of thale cress (Arabidopsis thaliana) root tissues (PlantEx), achieving a four-fold resolution increase over conventional microscopy. Our results highlight the microtubule cytoskeleton organization and interaction between molecularly defined cellular constituents. Combining PlantEx with stimulated emission depletion (STED) microscopy, we increase nanoscale resolution and visualize the complex organization of subcellular organelles from intact tissues by example of the densely packed COPI-coated vesicles associated with the Golgi apparatus and put these into a cellular structural context. Our results show that expansion microscopy can be applied to increase effective imaging resolution in Arabidopsis root specimens.
{"title":"Super-resolution expansion microscopy in plant roots","authors":"Michelle Gallei, Sven Truckenbrodt, Caroline Kreuzinger, Syamala Inumella, Vitali Vistunou, Christoph Sommer, Mojtaba R Tavakoli, Nathalie Agudelo Dueñas, Jakob Vorlaufer, Wiebke Jahr, Marek Randuch, Alexander Johnson, Eva Benková, Jiří Friml, Johann G Danzl","doi":"10.1093/plcell/koaf006","DOIUrl":"https://doi.org/10.1093/plcell/koaf006","url":null,"abstract":"Super-resolution methods provide far better spatial resolution than the optical diffraction limit of about half the wavelength of light (∼200-300 nm). Nevertheless, they have yet to attain widespread use in plants, largely due to plants’ challenging optical properties. Expansion microscopy improves effective resolution by isotropically increasing the physical distances between sample structures while preserving relative spatial arrangements and clearing the sample. However, its application to plants has been hindered by the rigid, mechanically cohesive structure of plant tissues. Here, we report on whole-mount expansion microscopy of thale cress (Arabidopsis thaliana) root tissues (PlantEx), achieving a four-fold resolution increase over conventional microscopy. Our results highlight the microtubule cytoskeleton organization and interaction between molecularly defined cellular constituents. Combining PlantEx with stimulated emission depletion (STED) microscopy, we increase nanoscale resolution and visualize the complex organization of subcellular organelles from intact tissues by example of the densely packed COPI-coated vesicles associated with the Golgi apparatus and put these into a cellular structural context. Our results show that expansion microscopy can be applied to increase effective imaging resolution in Arabidopsis root specimens.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chunhao Liu, An Li, Zhonglong Guo, Ningcong Chen, Yin Wang, Wenxiong Tang, Yuexin Wu, Jingyi Liu, Zihao Wang, Lei Li, Xin-Qiang He
Tracheary elements (TEs) are vital in the transport of various substances and contribute to plant growth. The differentiation of TEs is complex and regulated by a variety of microRNAs (miRNAs). However, the dynamic changes in miRNAs during each stage of TE differentiation remain unclear, and the miRNA regulatory network is not yet complete. This study employed Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL) to profile the miRNome during TE differentiation in Arabidopsis (Arabidopsis thaliana) and established comprehensive miRNA co-expression networks functioning at the different stages of TE differentiation. Two negatively correlated modules exist in the miRNA networks, each exhibiting strong intra-module positive correlation and strong inter-module negative correlation. Thus, the two modules may play opposite roles in TE differentiation and vascular development. Indeed, we found that miR408 promotes cambium formation and TE differentiation, consistent with miR408 as a key node in the networks of fate determination and the initiation of TE differentiation. Additionally, we found that miR163 inhibits secondary cell wall formation and TE differentiation, corresponding to miR163 as a key node in the TE maturation network. Moreover, we discovered that the miRNA co-expression network in poplar (Populus tomentosa) xylem development is also composed of two negatively correlated modules that contain miRNAs orthologous to those in Arabidopsis. Therefore, the two negatively correlated modules of the miRNA co-expression network are likely conserved and fundamental to xylem TE differentiation. These results provide insights into microRNA regulation in plant development.
{"title":"MicroRNA analysis reveals two modules that antagonistically regulate xylem tracheary element development in Arabidopsis","authors":"Chunhao Liu, An Li, Zhonglong Guo, Ningcong Chen, Yin Wang, Wenxiong Tang, Yuexin Wu, Jingyi Liu, Zihao Wang, Lei Li, Xin-Qiang He","doi":"10.1093/plcell/koaf011","DOIUrl":"https://doi.org/10.1093/plcell/koaf011","url":null,"abstract":"Tracheary elements (TEs) are vital in the transport of various substances and contribute to plant growth. The differentiation of TEs is complex and regulated by a variety of microRNAs (miRNAs). However, the dynamic changes in miRNAs during each stage of TE differentiation remain unclear, and the miRNA regulatory network is not yet complete. This study employed Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL) to profile the miRNome during TE differentiation in Arabidopsis (Arabidopsis thaliana) and established comprehensive miRNA co-expression networks functioning at the different stages of TE differentiation. Two negatively correlated modules exist in the miRNA networks, each exhibiting strong intra-module positive correlation and strong inter-module negative correlation. Thus, the two modules may play opposite roles in TE differentiation and vascular development. Indeed, we found that miR408 promotes cambium formation and TE differentiation, consistent with miR408 as a key node in the networks of fate determination and the initiation of TE differentiation. Additionally, we found that miR163 inhibits secondary cell wall formation and TE differentiation, corresponding to miR163 as a key node in the TE maturation network. Moreover, we discovered that the miRNA co-expression network in poplar (Populus tomentosa) xylem development is also composed of two negatively correlated modules that contain miRNAs orthologous to those in Arabidopsis. Therefore, the two negatively correlated modules of the miRNA co-expression network are likely conserved and fundamental to xylem TE differentiation. These results provide insights into microRNA regulation in plant development.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sai Wang, Siqi Ge, Xianfeng Liu, Lina Cheng, Ruizhen Li, Yang Liu, Yue Cai, Sida Meng, Changhua Tan, Cai-Zhong Jiang, Mingfang Qi, Tianlai Li, Tao Xu
Drought stress substantially decreases crop yields by causing flowers and fruits to detach prematurely. However, the molecular mechanisms modulating organ abscission under drought stress remain unclear. Here, we show that expression of CALMODULIN2 (CaM2) is specifically and sharply increased in the pedicel abscission zone (AZ) in response to drought and plays a positive role in drought-induced flower drop in tomato (Solanum lycopersicum). Due to partial functional redundancy with SlCaM6, we generated the Slcam2 Slcam6 double mutant, which showed minimal flower drop under drought. SlCaM2 and SlCaM6 interacted with the transcription factor Signal responsive 3L (SlSR3L), with the three proteins operating in the same pathway, based on genetic data. We identified Protease inhibitor26 (SlPI26) as a target gene of SlSR3L by DNA affinity purification sequencing (DAP-Seq) and transcriptome analysis. SlPI26 specifically inhibited the activity of the phytaspase SlPhyt2, hence preventing the generation of active phytosulfokine peptide and negatively regulating drought-induced flower drop. SlCaM2 and SlCaM6 enhanced the repression of SlPI26 expression by SlSR3L, promoting drought-induced flower drop. In addition, the Non-phototropic hypocotyl3 (SlNPH3)–Cullin3 (SlCUL3) complex, which relies on auxin, interacted with SlSR3L to induce its degradation. However, under drought conditions, SlNPH3–SlCUL3 function is compromised due to lower auxin concentration. These results uncover a regulatory network that precisely controls floral drop in response to drought stress.
{"title":"A regulatory network involving calmodulin controls phytosulfokine peptide processing during drought-induced flower abscission","authors":"Sai Wang, Siqi Ge, Xianfeng Liu, Lina Cheng, Ruizhen Li, Yang Liu, Yue Cai, Sida Meng, Changhua Tan, Cai-Zhong Jiang, Mingfang Qi, Tianlai Li, Tao Xu","doi":"10.1093/plcell/koaf013","DOIUrl":"https://doi.org/10.1093/plcell/koaf013","url":null,"abstract":"Drought stress substantially decreases crop yields by causing flowers and fruits to detach prematurely. However, the molecular mechanisms modulating organ abscission under drought stress remain unclear. Here, we show that expression of CALMODULIN2 (CaM2) is specifically and sharply increased in the pedicel abscission zone (AZ) in response to drought and plays a positive role in drought-induced flower drop in tomato (Solanum lycopersicum). Due to partial functional redundancy with SlCaM6, we generated the Slcam2 Slcam6 double mutant, which showed minimal flower drop under drought. SlCaM2 and SlCaM6 interacted with the transcription factor Signal responsive 3L (SlSR3L), with the three proteins operating in the same pathway, based on genetic data. We identified Protease inhibitor26 (SlPI26) as a target gene of SlSR3L by DNA affinity purification sequencing (DAP-Seq) and transcriptome analysis. SlPI26 specifically inhibited the activity of the phytaspase SlPhyt2, hence preventing the generation of active phytosulfokine peptide and negatively regulating drought-induced flower drop. SlCaM2 and SlCaM6 enhanced the repression of SlPI26 expression by SlSR3L, promoting drought-induced flower drop. In addition, the Non-phototropic hypocotyl3 (SlNPH3)–Cullin3 (SlCUL3) complex, which relies on auxin, interacted with SlSR3L to induce its degradation. However, under drought conditions, SlNPH3–SlCUL3 function is compromised due to lower auxin concentration. These results uncover a regulatory network that precisely controls floral drop in response to drought stress.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng Zhang, Robert Sharwood, Adam Carroll, Gonzalo M Estavillo, Susanne von Caemmerer, Robert T Furbank
Many C4 plants are used as food and fodder crops and often display improved resource use efficiency compared to C3 plants. However, the response of C4 plants to future extreme conditions such as heatwaves is less understood. Here, Setaria viridis, an emerging C4 model grass, was grown under long-term high temperature stress for two weeks (42°C, compared to 28°C). This resulted in stunted growth, but surprisingly had little impact on leaf thickness, leaf area-based photosynthetic rates and bundle sheath leakiness. Dark respiration rates increased and there were major alterations in carbon and nitrogen metabolism in the heat-stressed plants. Abscisic acid and indole-acetic acid–amino acid conjugates accumulated in the heat-stressed plants, consistent with transcriptional changes. Leaf transcriptomics, proteomics and metabolomics analyses were carried out and mapped onto the metabolic pathways of photosynthesis, respiration, carbon/nitrogen metabolism and phytohormone biosynthesis and signaling. An in-depth analysis of correlations between transcripts and their corresponding proteins revealed strong differences between groups in the strengths and signs of correlations. Overall, many stress signaling pathways were upregulated, consistent with multiple signals leading to reduced plant growth. A systems-based model of the plant response to long-term heat stress is presented based on the oxidative stress, phytohormone and sugar signaling pathways.
{"title":"Systems analysis of long-term heat stress responses in the C4 grass Setaria viridis","authors":"Peng Zhang, Robert Sharwood, Adam Carroll, Gonzalo M Estavillo, Susanne von Caemmerer, Robert T Furbank","doi":"10.1093/plcell/koaf005","DOIUrl":"https://doi.org/10.1093/plcell/koaf005","url":null,"abstract":"Many C4 plants are used as food and fodder crops and often display improved resource use efficiency compared to C3 plants. However, the response of C4 plants to future extreme conditions such as heatwaves is less understood. Here, Setaria viridis, an emerging C4 model grass, was grown under long-term high temperature stress for two weeks (42°C, compared to 28°C). This resulted in stunted growth, but surprisingly had little impact on leaf thickness, leaf area-based photosynthetic rates and bundle sheath leakiness. Dark respiration rates increased and there were major alterations in carbon and nitrogen metabolism in the heat-stressed plants. Abscisic acid and indole-acetic acid–amino acid conjugates accumulated in the heat-stressed plants, consistent with transcriptional changes. Leaf transcriptomics, proteomics and metabolomics analyses were carried out and mapped onto the metabolic pathways of photosynthesis, respiration, carbon/nitrogen metabolism and phytohormone biosynthesis and signaling. An in-depth analysis of correlations between transcripts and their corresponding proteins revealed strong differences between groups in the strengths and signs of correlations. Overall, many stress signaling pathways were upregulated, consistent with multiple signals leading to reduced plant growth. A systems-based model of the plant response to long-term heat stress is presented based on the oxidative stress, phytohormone and sugar signaling pathways.","PeriodicalId":501012,"journal":{"name":"The Plant Cell","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}