SHOOT-MERISTEMLESS defines and serves as a marker for productive shoot progenitor cells, facilitating de novo shoot regeneration from callus in tissue culture.
{"title":"Stm is required for fate establishment of productive shoot progenitor cells in Arabidopsis tissue culture","authors":"Ning Zhai, Dixiang Xie, Lin Xu","doi":"10.1093/plphys/kiaf671","DOIUrl":"https://doi.org/10.1093/plphys/kiaf671","url":null,"abstract":"SHOOT-MERISTEMLESS defines and serves as a marker for productive shoot progenitor cells, facilitating de novo shoot regeneration from callus in tissue culture.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"7 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Plant grafting, a series of tissue reunion processes, exhibits varying levels of compatibility across different species. Despite extensive research, the response of the scion to various compatible rootstocks remains poorly understood. In this study, we utilized transcriptomic analyses and gene functional validation experiments to investigate the role of xyloglucan endotransglucosylase/hydrolase (XTH) genes and their products in graft healing, specifically examining their effects on callus proliferation and graft survival in response to rootstocks with differing compatibilities across multiple species. Our results indicated that the less compatible bottle gourd rootstocks stimulate increased callus proliferation at the graft junctions with melon (Cucumis melo) scions. Virus-induced gene silencing of a highly expressed XTH gene, CmXTH9, in melon led to lower survival rates and reduced callus proliferation at the graft boundary. Furthermore, grafting accompanied upregulation of 25-55% of XTH family genes in the grafts of Arabidopsis thaliana, Nicotiana benthamiana, and Oryza sativa, which are distributed across different phylogenetic branches. Successful heterografts typically induced more family genes with greater upregulation than unsuccessful grafts. Consistently, an Arabidopsis Atxth4;Atxth7 mutant decreased grafting success rates and diminished callus proliferation at the wound site. These results underscore the conserved function of XTHs in graft union development and highlight their role in graft healing.
{"title":"Xyloglucan endotransglucosylase/hydrolase family genes are required for the plant graft union formation through callus proliferation.","authors":"Mu Xiong,Ting Zhang,Xin Qian,Akebaierjiang Kadeer,Ken-Ichi Kurotani,Ling Li,Changjin Liu,Xiangshuai Wu,Zhilong Bie,Michitaka Notaguchi,Yuan Huang","doi":"10.1093/plphys/kiag030","DOIUrl":"https://doi.org/10.1093/plphys/kiag030","url":null,"abstract":"Plant grafting, a series of tissue reunion processes, exhibits varying levels of compatibility across different species. Despite extensive research, the response of the scion to various compatible rootstocks remains poorly understood. In this study, we utilized transcriptomic analyses and gene functional validation experiments to investigate the role of xyloglucan endotransglucosylase/hydrolase (XTH) genes and their products in graft healing, specifically examining their effects on callus proliferation and graft survival in response to rootstocks with differing compatibilities across multiple species. Our results indicated that the less compatible bottle gourd rootstocks stimulate increased callus proliferation at the graft junctions with melon (Cucumis melo) scions. Virus-induced gene silencing of a highly expressed XTH gene, CmXTH9, in melon led to lower survival rates and reduced callus proliferation at the graft boundary. Furthermore, grafting accompanied upregulation of 25-55% of XTH family genes in the grafts of Arabidopsis thaliana, Nicotiana benthamiana, and Oryza sativa, which are distributed across different phylogenetic branches. Successful heterografts typically induced more family genes with greater upregulation than unsuccessful grafts. Consistently, an Arabidopsis Atxth4;Atxth7 mutant decreased grafting success rates and diminished callus proliferation at the wound site. These results underscore the conserved function of XTHs in graft union development and highlight their role in graft healing.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"1 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultraviolet-B (UV-B) irradiation is an effective elicitor for the biosynthesis of pharmaceutically relevant monoterpenoid indole alkaloids (MIAs). Uncaria rhynchophylla (UR) produces numerous valuable MIAs, such as rhynchophylline and isorhynchophylline, which have huge chemotherapeutic potential. However, the mechanism underlying UV-B-induced MIAs remains elusive in MIA-producing plants. Here, we performed integrative transcriptome and metabolome analyses and found that UV-B distinctly induced MIA accumulation in UR leaves. Furthermore, we report that two UV-B-responsive transcription factors, UrWRKY40 and ELONGATED HYPOCOTYL 5 (UrHY5), cooperatively promote UV-B-induced MIA biosynthesis by activating MIA structural genes (UrSTR1, UrCPR1) via binding to their promoters (W-box and T/G-box elements). Comparative interactomics and dual-luciferase assays demonstrated that UrWRKY40 physically interacts with UrHY5 and represses its transcriptional activity under normal white light conditions. However, UV-B disrupted the formation of the UrWRKY40-UrHY5 complex and attenuated the repressive effects of UrWRKY40 on UrHY5 activity, thereby enhancing UrHY5-driven transactivation of downstream MIA structural genes. In addition, UV-B stimulated limited ABA production, which partially repressed UrWRKY40 expression, but not enough to override its induction by UV-B. In the presence of ABA, the UrWRKY40-UrHY5 interaction dissolved, which in turn released UrHY5 from repression, allowing it to activate MIA biosynthesis. These findings uncover a mechanism by which the UrWRKY40-UrHY5 module positively regulates UV-B-induced MIA biosynthesis by coordinating UV-B and ABA signaling, and provide a strategic framework for enhancing high-value MIA production through genetic manipulation.
{"title":"The UrWRKY40-UrHY5 module regul*ates the biosynthesis of UV-B-induced monoterpene indole alkaloids in Uncaria rhynchophylla.","authors":"Jia-Shun Yang,Hao-Cheng Lou,Hong Zhang,Xiao-Jun Pan,Xi Bao,Yu-Wen Qin,Yang-Ping Yang,Ren-Juan Qian,Pei-Long Wang,Jin-Guo Cheng,Zhi-Gang Wu","doi":"10.1093/plphys/kiag039","DOIUrl":"https://doi.org/10.1093/plphys/kiag039","url":null,"abstract":"Ultraviolet-B (UV-B) irradiation is an effective elicitor for the biosynthesis of pharmaceutically relevant monoterpenoid indole alkaloids (MIAs). Uncaria rhynchophylla (UR) produces numerous valuable MIAs, such as rhynchophylline and isorhynchophylline, which have huge chemotherapeutic potential. However, the mechanism underlying UV-B-induced MIAs remains elusive in MIA-producing plants. Here, we performed integrative transcriptome and metabolome analyses and found that UV-B distinctly induced MIA accumulation in UR leaves. Furthermore, we report that two UV-B-responsive transcription factors, UrWRKY40 and ELONGATED HYPOCOTYL 5 (UrHY5), cooperatively promote UV-B-induced MIA biosynthesis by activating MIA structural genes (UrSTR1, UrCPR1) via binding to their promoters (W-box and T/G-box elements). Comparative interactomics and dual-luciferase assays demonstrated that UrWRKY40 physically interacts with UrHY5 and represses its transcriptional activity under normal white light conditions. However, UV-B disrupted the formation of the UrWRKY40-UrHY5 complex and attenuated the repressive effects of UrWRKY40 on UrHY5 activity, thereby enhancing UrHY5-driven transactivation of downstream MIA structural genes. In addition, UV-B stimulated limited ABA production, which partially repressed UrWRKY40 expression, but not enough to override its induction by UV-B. In the presence of ABA, the UrWRKY40-UrHY5 interaction dissolved, which in turn released UrHY5 from repression, allowing it to activate MIA biosynthesis. These findings uncover a mechanism by which the UrWRKY40-UrHY5 module positively regulates UV-B-induced MIA biosynthesis by coordinating UV-B and ABA signaling, and provide a strategic framework for enhancing high-value MIA production through genetic manipulation.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"117 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146070011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiwei Chen,Zhonghua Li,Zhengyang Qi,Lu Qiao,Xiao Zhang,Lili Tu,Xianlong Zhang,Maojun Wang
The flavonoid metabolic pathway plays a pivotal role in plant growth, development, and environmental adaptation, and has undergone significant selection during cotton (Gossypium hirsutum) domestication. However, the functional role of flavonoid metabolism in fiber development remains poorly understood. In this study, we explore its functional significance in cotton fiber development by identifying expression quantitative trait loci (eQTLs) that regulate flavonoid biosynthesis and fiber-related traits. Through integrative eQTL mapping and transcriptomic analyses, we identified regulatory variants associated with key transcription factor and biosynthesis genes, including GhMYB46, GhMYB111, chalcone synthase (GhCHS) and dihydroflavonol 4-reductase (GhDFR). Functional characterization revealed that GhCHS and GhDFR play distinct roles in fiber development: in GhCHS-RNAi lines, excessive reactive oxygen species (ROS) accumulation during fiber elongation impaired cell expansion, resulting in significantly shorter fibers; in contrast, GhDFR suppression disrupted cellulose biosynthesis and secondary cell wall thickening, leading to fibers with increased micronaire values. Together, these findings indicate that eQTL-mediated regulatory variation reshapes the expression of flavonoid pathway genes, thereby influencing both fiber elongation and secondary cell wall formation. Such regulatory remodeling underscores the functional integration of flavonoid metabolism into fiber development and highlights its potential as a valuable genetic resource for future fiber improvement.
{"title":"Flavonoid metabolism enzymes GhCHS and GhDFR influence fiber elongation and secondary cell wall synthesis in cotton.","authors":"Zhiwei Chen,Zhonghua Li,Zhengyang Qi,Lu Qiao,Xiao Zhang,Lili Tu,Xianlong Zhang,Maojun Wang","doi":"10.1093/plphys/kiag031","DOIUrl":"https://doi.org/10.1093/plphys/kiag031","url":null,"abstract":"The flavonoid metabolic pathway plays a pivotal role in plant growth, development, and environmental adaptation, and has undergone significant selection during cotton (Gossypium hirsutum) domestication. However, the functional role of flavonoid metabolism in fiber development remains poorly understood. In this study, we explore its functional significance in cotton fiber development by identifying expression quantitative trait loci (eQTLs) that regulate flavonoid biosynthesis and fiber-related traits. Through integrative eQTL mapping and transcriptomic analyses, we identified regulatory variants associated with key transcription factor and biosynthesis genes, including GhMYB46, GhMYB111, chalcone synthase (GhCHS) and dihydroflavonol 4-reductase (GhDFR). Functional characterization revealed that GhCHS and GhDFR play distinct roles in fiber development: in GhCHS-RNAi lines, excessive reactive oxygen species (ROS) accumulation during fiber elongation impaired cell expansion, resulting in significantly shorter fibers; in contrast, GhDFR suppression disrupted cellulose biosynthesis and secondary cell wall thickening, leading to fibers with increased micronaire values. Together, these findings indicate that eQTL-mediated regulatory variation reshapes the expression of flavonoid pathway genes, thereby influencing both fiber elongation and secondary cell wall formation. Such regulatory remodeling underscores the functional integration of flavonoid metabolism into fiber development and highlights its potential as a valuable genetic resource for future fiber improvement.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"29 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lipin proteins, a family of phosphatidic acid phosphatases (PAHs), are key regulators of lipid metabolism, storage, and homeostasis across eukaryotes. While Arabidopsis (Arabidopsis thaliana) lipins function in lipid biosynthesis and gene regulation, their roles in lipid droplet (LD) biogenesis and lipid homeostasis remain largely unknown. Here, we show that double knockout of two PAH genes (PAH1/2) results in impaired LD biogenesis, accelerated triacylglycerol (TAG) hydrolysis, and lipid imbalance. pah1/2 mutant leaves exhibited a marked reduction in TAG levels and a significant decrease in LD size, while the rates of TAG and diacylglycerol (DAG) synthesis remained largely unchanged. In seeds, PAH1/2 disruption minimally affected TAG content but significantly reduced LD size. Fatty acid feeding experiments demonstrated impaired LD formation and increased lipotoxicity in pah1/2 leaves and seedlings. Furthermore, knockout of PAH1/2 in mutants with enhanced fatty acid flux through phosphatidylcholine (PC) led to severe reductions in leaf TAG levels, despite increases in TAG synthesis rates, indicating accelerated TAG turnover. Phosphatidic acid, free fatty acids, and PC accumulated, leading to massive proliferation of endoplasmic reticulum membranes and severe growth and developmental defects. These findings demonstrate evolutionarily conserved roles for PAH1/2 in LD biogenesis, membrane lipid homeostasis, and cellular protection against lipotoxicity, particularly under conditions of elevated fatty acid flux.
{"title":"Arabidopsis lipins mediate lipid droplet biogenesis to protect cells from lipotoxicity.","authors":"Jilian Fan,Dongling Xie,Changcheng Xu","doi":"10.1093/plphys/kiag027","DOIUrl":"https://doi.org/10.1093/plphys/kiag027","url":null,"abstract":"Lipin proteins, a family of phosphatidic acid phosphatases (PAHs), are key regulators of lipid metabolism, storage, and homeostasis across eukaryotes. While Arabidopsis (Arabidopsis thaliana) lipins function in lipid biosynthesis and gene regulation, their roles in lipid droplet (LD) biogenesis and lipid homeostasis remain largely unknown. Here, we show that double knockout of two PAH genes (PAH1/2) results in impaired LD biogenesis, accelerated triacylglycerol (TAG) hydrolysis, and lipid imbalance. pah1/2 mutant leaves exhibited a marked reduction in TAG levels and a significant decrease in LD size, while the rates of TAG and diacylglycerol (DAG) synthesis remained largely unchanged. In seeds, PAH1/2 disruption minimally affected TAG content but significantly reduced LD size. Fatty acid feeding experiments demonstrated impaired LD formation and increased lipotoxicity in pah1/2 leaves and seedlings. Furthermore, knockout of PAH1/2 in mutants with enhanced fatty acid flux through phosphatidylcholine (PC) led to severe reductions in leaf TAG levels, despite increases in TAG synthesis rates, indicating accelerated TAG turnover. Phosphatidic acid, free fatty acids, and PC accumulated, leading to massive proliferation of endoplasmic reticulum membranes and severe growth and developmental defects. These findings demonstrate evolutionarily conserved roles for PAH1/2 in LD biogenesis, membrane lipid homeostasis, and cellular protection against lipotoxicity, particularly under conditions of elevated fatty acid flux.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"28 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146069908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felix J Martínez Rivas,Milena A Smith,Zahra Zangishei,Saleh Alseekh,Björn Usadel,William C Plaxton,Alisdair R Fernie
Plant phosphoenolpyruvate carboxylases (PEPCs) are ubiquitously expressed as cytosolic Class-1 PEPC homotetramers composed of 107 kDa plant-type PEPC (PTPC) subunits that are highly sensitive to allosteric inhibition by malate. Class-2 PEPC heterooctameric complexes that are desensitized to malate inhibition also exist in certain sink tissues due to the interaction of a Class-1 PEPC with unrelated 118 kDa bacterial-type PEPC (BTPC) polypeptides. Class-2 PEPCs dynamically associate with the mitochondrial outer envelope and have been hypothesized to support sustained anaplerotic flux and respiratory CO₂ refixation in malate-rich sink tissues, including immature tomato fruit. The current study generated CRISPR-Cas9-edited tomato lines with targeted disruption of the BTPC gene and investigated the impact on fruit development, metabolism, and transcriptional regulation. Immunoblotting and co-immunoprecipitation confirmed the absence of BTPC polypeptides and Class-2 PEPC complexes in the edited lines. Fruits from the edited plants were 25% smaller and 40% lighter and required up to 10 additional days to complete ripening compared to the WT. Metabolomic analysis across ripening stages revealed substantial reductions in malate and citrate, with elevated sugars and amino acids, indicating reprogrammed carbon flux. RNA-seq data showed downregulation of genes for cell wall remodeling, sugar transport, and ethylene-responsive transcription factors. These results provide direct evidence that BTPC is essential for organic acid balance, sugar metabolism, and ripening regulation in tomato. Its absence perturbs metabolic homeostasis and developmental progression, positioning BTPC as a strategic target for enhancing fruit quality traits through genetic engineering.
{"title":"Malate matters: disrupting bacterial-type phosphoenolpyruvate carboxylase (BTPC) rewires tomato fruit development.","authors":"Felix J Martínez Rivas,Milena A Smith,Zahra Zangishei,Saleh Alseekh,Björn Usadel,William C Plaxton,Alisdair R Fernie","doi":"10.1093/plphys/kiag026","DOIUrl":"https://doi.org/10.1093/plphys/kiag026","url":null,"abstract":"Plant phosphoenolpyruvate carboxylases (PEPCs) are ubiquitously expressed as cytosolic Class-1 PEPC homotetramers composed of 107 kDa plant-type PEPC (PTPC) subunits that are highly sensitive to allosteric inhibition by malate. Class-2 PEPC heterooctameric complexes that are desensitized to malate inhibition also exist in certain sink tissues due to the interaction of a Class-1 PEPC with unrelated 118 kDa bacterial-type PEPC (BTPC) polypeptides. Class-2 PEPCs dynamically associate with the mitochondrial outer envelope and have been hypothesized to support sustained anaplerotic flux and respiratory CO₂ refixation in malate-rich sink tissues, including immature tomato fruit. The current study generated CRISPR-Cas9-edited tomato lines with targeted disruption of the BTPC gene and investigated the impact on fruit development, metabolism, and transcriptional regulation. Immunoblotting and co-immunoprecipitation confirmed the absence of BTPC polypeptides and Class-2 PEPC complexes in the edited lines. Fruits from the edited plants were 25% smaller and 40% lighter and required up to 10 additional days to complete ripening compared to the WT. Metabolomic analysis across ripening stages revealed substantial reductions in malate and citrate, with elevated sugars and amino acids, indicating reprogrammed carbon flux. RNA-seq data showed downregulation of genes for cell wall remodeling, sugar transport, and ethylene-responsive transcription factors. These results provide direct evidence that BTPC is essential for organic acid balance, sugar metabolism, and ripening regulation in tomato. Its absence perturbs metabolic homeostasis and developmental progression, positioning BTPC as a strategic target for enhancing fruit quality traits through genetic engineering.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"44 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146069912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Houben Maarten,Vaughan-Hirsch John,Pattyn Jolien,Mou Wangshu,Roden Stijn,Roig Martinez Albert,Kabak N Elif,Rodrigues Savio,Polko Asia,De Coninck Barbara,Kieber J Joseph,Voet Arnout,Van de Poel Bram
In seed plants, ethylene is produced from 1-aminocyclopropane-1-carboxylic acid (ACC) by the enzyme ACC-oxidase (ACO). Despite the critical role of ACO in ethylene biosynthesis, the ACO gene family has not been fully characterized in Arabidopsis (Arabidopsis thaliana). This study investigated the five ACO genes in Arabidopsis, revealing distinct tissue-specific and developmental expression patterns. Each ACO enzyme exhibited a unique enzymatic capacity for ethylene production, facilitating isoform-specific regulation of ethylene biosynthesis. At the subcellular level, ACO localized predominantly in the cytosol, where ethylene biosynthesis likely occurs, but, unexpectedly, also in the nucleus. Through reverse genetics, including single and higher-order aco mutants, we observed a high degree of gene redundancy, sustaining ethylene biosynthesis. Disruption of all five ACO genes resulted in plants unable to produce ethylene but did not adversely affect seedling, vegetative, or reproductive development. However, some development processes associated with high rates of ethylene production, such as germination and petal abscission, were impaired in the aco quintuple mutant, while others, such as leaf senescence, were not. This suggests that modulation of ethylene emission rates by ACOs is key in determining specific developmental processes. Furthermore, the aco quintuple mutant showed impaired responses to abiotic (e.g., nutrient deficiency and metal toxicity) and biotic stress (e.g., Botrytis cinerea), akin to ethylene-insensitive plants. This highlights the pivotal role of ethylene in modulating stress responses. In conclusion, the ACO gene family plays a vital role in fine-tuning ethylene biosynthesis in a spatial-temporal way, thereby modulating plant development and stress resilience.
{"title":"1-Aminocyclopropane-1-carboxylic acid oxidase determines the fate of ethylene biosynthesis in a tissue-specific way.","authors":"Houben Maarten,Vaughan-Hirsch John,Pattyn Jolien,Mou Wangshu,Roden Stijn,Roig Martinez Albert,Kabak N Elif,Rodrigues Savio,Polko Asia,De Coninck Barbara,Kieber J Joseph,Voet Arnout,Van de Poel Bram","doi":"10.1093/plphys/kiag025","DOIUrl":"https://doi.org/10.1093/plphys/kiag025","url":null,"abstract":"In seed plants, ethylene is produced from 1-aminocyclopropane-1-carboxylic acid (ACC) by the enzyme ACC-oxidase (ACO). Despite the critical role of ACO in ethylene biosynthesis, the ACO gene family has not been fully characterized in Arabidopsis (Arabidopsis thaliana). This study investigated the five ACO genes in Arabidopsis, revealing distinct tissue-specific and developmental expression patterns. Each ACO enzyme exhibited a unique enzymatic capacity for ethylene production, facilitating isoform-specific regulation of ethylene biosynthesis. At the subcellular level, ACO localized predominantly in the cytosol, where ethylene biosynthesis likely occurs, but, unexpectedly, also in the nucleus. Through reverse genetics, including single and higher-order aco mutants, we observed a high degree of gene redundancy, sustaining ethylene biosynthesis. Disruption of all five ACO genes resulted in plants unable to produce ethylene but did not adversely affect seedling, vegetative, or reproductive development. However, some development processes associated with high rates of ethylene production, such as germination and petal abscission, were impaired in the aco quintuple mutant, while others, such as leaf senescence, were not. This suggests that modulation of ethylene emission rates by ACOs is key in determining specific developmental processes. Furthermore, the aco quintuple mutant showed impaired responses to abiotic (e.g., nutrient deficiency and metal toxicity) and biotic stress (e.g., Botrytis cinerea), akin to ethylene-insensitive plants. This highlights the pivotal role of ethylene in modulating stress responses. In conclusion, the ACO gene family plays a vital role in fine-tuning ethylene biosynthesis in a spatial-temporal way, thereby modulating plant development and stress resilience.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"42 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146069905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saori Suga,Ryoga Inoue,Syogo Wada,Yumiko Shirano,Natsumi Aoki,Takamasa Suzuki,Anuphon Laohavisit,Ayato Sato,Satoko Yoshida
Parasitic weeds in the Orobanchaceae family pose a major threat to crop production worldwide. Parasitic plants develop specialized invasive structures called haustoria, which penetrate host tissues to establish connections and absorb nutrients. The formation of prehaustoria, early-stage haustorial structures, is triggered by host-derived haustorium-inducing factors (HIFs), such as 2,6-dimethoxy-1,4-benzoquinone (DMBQ) and syringic acid. Since prehaustorium formation is a critical initial step in parasitism, its inhibition represents a promising strategy for controlling parasitic weeds. In this study, we performed a chemical screening to identify inhibitors of prehaustorium formation and discovered a compound, designated Haustorium INhibiting Compound 55 (HINC55), that effectively inhibits prehaustorium formation in the parasitic plants Striga (Striga hermonthica) and Phtheirospermum japonicum. Notably, HINC55 suppressed prehaustorium induction by quinones and phenolics, but not by cytokinins in Striga. Furthermore, HINC55 inhibited DMBQ-induced stomata closure in both Arabidopsis (Arabidopsis thaliana) and P. japonicum, suggesting that HINC55 functions as an inhibitor of plant quinone signaling. We used HINC55 to evaluate the composition of HIFs in host root exudates. HINC55 partially suppressed prehaustorium formation in Striga and almost completely in P. japonicum when induced by host root exudates, reflecting the broader HIF responsiveness of Striga. Transcriptome analysis further confirmed the stronger suppression in P. japonicum in response to rice (Oryza sativa) root exudate than in Striga. Overall, HINC55 serves as a tool for investigating plant quinone signaling and dissecting host-parasite chemical communications, as well as a compound for developing novel strategies to control parasitic weeds.
{"title":"A quinone signaling inhibitor enables functional dissection of haustorium-inducing factors in Orobanchaceae parasitic plants.","authors":"Saori Suga,Ryoga Inoue,Syogo Wada,Yumiko Shirano,Natsumi Aoki,Takamasa Suzuki,Anuphon Laohavisit,Ayato Sato,Satoko Yoshida","doi":"10.1093/plphys/kiaf686","DOIUrl":"https://doi.org/10.1093/plphys/kiaf686","url":null,"abstract":"Parasitic weeds in the Orobanchaceae family pose a major threat to crop production worldwide. Parasitic plants develop specialized invasive structures called haustoria, which penetrate host tissues to establish connections and absorb nutrients. The formation of prehaustoria, early-stage haustorial structures, is triggered by host-derived haustorium-inducing factors (HIFs), such as 2,6-dimethoxy-1,4-benzoquinone (DMBQ) and syringic acid. Since prehaustorium formation is a critical initial step in parasitism, its inhibition represents a promising strategy for controlling parasitic weeds. In this study, we performed a chemical screening to identify inhibitors of prehaustorium formation and discovered a compound, designated Haustorium INhibiting Compound 55 (HINC55), that effectively inhibits prehaustorium formation in the parasitic plants Striga (Striga hermonthica) and Phtheirospermum japonicum. Notably, HINC55 suppressed prehaustorium induction by quinones and phenolics, but not by cytokinins in Striga. Furthermore, HINC55 inhibited DMBQ-induced stomata closure in both Arabidopsis (Arabidopsis thaliana) and P. japonicum, suggesting that HINC55 functions as an inhibitor of plant quinone signaling. We used HINC55 to evaluate the composition of HIFs in host root exudates. HINC55 partially suppressed prehaustorium formation in Striga and almost completely in P. japonicum when induced by host root exudates, reflecting the broader HIF responsiveness of Striga. Transcriptome analysis further confirmed the stronger suppression in P. japonicum in response to rice (Oryza sativa) root exudate than in Striga. Overall, HINC55 serves as a tool for investigating plant quinone signaling and dissecting host-parasite chemical communications, as well as a compound for developing novel strategies to control parasitic weeds.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"58 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146069907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Parasitic plant development: A new chemical inhibitor of Striga haustoria development.","authors":"James M Bradley","doi":"10.1093/plphys/kiag036","DOIUrl":"https://doi.org/10.1093/plphys/kiag036","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"31 5 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146069998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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