Plants use light both as a resource for photosynthesis and as a signal about their environment. In response to light cues, plants can move their organs via directional growth driven by cell expansion. In dense vegetation where light is available in spatially heterogeneous patterns, plants need to navigate this space to improve the position of their photosynthetic tissues. In canopies blue light irradiance and red to far-red light ratio decrease due to absorption by chloroplasts, and these changes regulate distinct processes within the plant. Changes in light environment are detected by cryptochrome and phytochrome photoreceptors, both regulating Phytochrome Interacting Factors (PIFs) and thereby enhancing elongation in hypocotyls, stems and leaves, and inducing upward leaf movement (hyponasty). An additional class of photoreceptors, phototropins, decode horizontal light gradients to produce directional growth towards the light source (phototropism). Here we review the current state of knowledge on these differential growth responses to light cues, with specific emphasis on the regulatory pathways that translate light signaling in differential cell expansion. Downstream of the photoreceptors, the phytohormone auxin induces cell growth in shoot tissues, but also other phytohormones contribute to balancing light responses. Cell expansion is regulated primarily at the level of cell walls and a comparison of different transcriptome datasets reveals that only a small group of cell wall modifying genes are tightly regulated by shade cues. It remains poorly understood which cell layers are causal to the initiation of cellular expansion. Here we combine insights from different differential growth behaviors in different species and organs to generate different hypotheses for the cellular underpinnings of light-driven leaf movements.
{"title":"Plant movements: navigating the light environment.","authors":"Sanne E A Matton,Lisa Oskam,Ronald Pierik","doi":"10.1093/plphys/kiag110","DOIUrl":"https://doi.org/10.1093/plphys/kiag110","url":null,"abstract":"Plants use light both as a resource for photosynthesis and as a signal about their environment. In response to light cues, plants can move their organs via directional growth driven by cell expansion. In dense vegetation where light is available in spatially heterogeneous patterns, plants need to navigate this space to improve the position of their photosynthetic tissues. In canopies blue light irradiance and red to far-red light ratio decrease due to absorption by chloroplasts, and these changes regulate distinct processes within the plant. Changes in light environment are detected by cryptochrome and phytochrome photoreceptors, both regulating Phytochrome Interacting Factors (PIFs) and thereby enhancing elongation in hypocotyls, stems and leaves, and inducing upward leaf movement (hyponasty). An additional class of photoreceptors, phototropins, decode horizontal light gradients to produce directional growth towards the light source (phototropism). Here we review the current state of knowledge on these differential growth responses to light cues, with specific emphasis on the regulatory pathways that translate light signaling in differential cell expansion. Downstream of the photoreceptors, the phytohormone auxin induces cell growth in shoot tissues, but also other phytohormones contribute to balancing light responses. Cell expansion is regulated primarily at the level of cell walls and a comparison of different transcriptome datasets reveals that only a small group of cell wall modifying genes are tightly regulated by shade cues. It remains poorly understood which cell layers are causal to the initiation of cellular expansion. Here we combine insights from different differential growth behaviors in different species and organs to generate different hypotheses for the cellular underpinnings of light-driven leaf movements.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"19 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147351035","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}
The transition from vegetative to reproductive growth is critical in flowering plants. INDETERMINATE1 (ID1), a monocot-specific zinc finger transcription factor (TF), is thought to promote flowering by indirectly influencing ZCN8, the encoded protein of which transmits the florigen signal to downstream floral identity genes. However, the precise mechanism by which ID1 regulates floral transition in day-neutral maize remains poorly understood. Here, we characterized a floral transition-defective (ftd1) mutant that produces excess leaves and exhibits impaired reproductive development. Map-based cloning and complementation confirmed that ftd1 is an allele of id1. We demonstrated that ID1 is a nucleus-localized transcriptional activator that preferentially binds to the canonical GTC-core motif. Genome-wide binding and transcriptome analyses of ftd1 immature leaves identified potential target genes, including the flowering regulator gene MADS67 and the SPL gene SBP20. We further showed that ID1 physically interacts with MYB31 and TCP transcription factors, which synergistically enhance ID1-mediated transactivation of the MADS67 promoter. Genetic analyses indicated that ID1 acts epistatic to MADS67, and overexpression of MADS67 only partially rescued the id1 phenotype, indicating that MADS67 is necessary but insufficient for flowering. In parallel, the ID1-TCP20 complex activated SBP20, which in turn directly upregulated the florigen gene ZCN8. Collectively, our findings propose a dual-pathway model for ID1-mediated flowering regulation, in which ID1 orchestrates the floral transition through both a MADS67-dependent module (ID1+MYB31/TCP14/16/20-MADS67) and a parallel SBP20-ZCN8 module (ID1+TCP20-SBP20-ZCN8), thereby ensuring robust regulation of maize flowering time.
{"title":"INDETERMINATE1 coordinates with MYB31 and TCP to drive floral transition in the autonomous pathway of temperate maize.","authors":"Qingqian Zhou,Yongtian Qin,Yibo Li,Yu Zhang,Hainuo Dong,Zhixu Liu,Guifeng Wang,Jiong Wan,Meng Qiu,Tingting Wu,Xurui Ma,Yijian Feng,Xuehai Zhang,Jihua Tang,Zhiyuan Fu","doi":"10.1093/plphys/kiag098","DOIUrl":"https://doi.org/10.1093/plphys/kiag098","url":null,"abstract":"The transition from vegetative to reproductive growth is critical in flowering plants. INDETERMINATE1 (ID1), a monocot-specific zinc finger transcription factor (TF), is thought to promote flowering by indirectly influencing ZCN8, the encoded protein of which transmits the florigen signal to downstream floral identity genes. However, the precise mechanism by which ID1 regulates floral transition in day-neutral maize remains poorly understood. Here, we characterized a floral transition-defective (ftd1) mutant that produces excess leaves and exhibits impaired reproductive development. Map-based cloning and complementation confirmed that ftd1 is an allele of id1. We demonstrated that ID1 is a nucleus-localized transcriptional activator that preferentially binds to the canonical GTC-core motif. Genome-wide binding and transcriptome analyses of ftd1 immature leaves identified potential target genes, including the flowering regulator gene MADS67 and the SPL gene SBP20. We further showed that ID1 physically interacts with MYB31 and TCP transcription factors, which synergistically enhance ID1-mediated transactivation of the MADS67 promoter. Genetic analyses indicated that ID1 acts epistatic to MADS67, and overexpression of MADS67 only partially rescued the id1 phenotype, indicating that MADS67 is necessary but insufficient for flowering. In parallel, the ID1-TCP20 complex activated SBP20, which in turn directly upregulated the florigen gene ZCN8. Collectively, our findings propose a dual-pathway model for ID1-mediated flowering regulation, in which ID1 orchestrates the floral transition through both a MADS67-dependent module (ID1+MYB31/TCP14/16/20-MADS67) and a parallel SBP20-ZCN8 module (ID1+TCP20-SBP20-ZCN8), thereby ensuring robust regulation of maize flowering time.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"43 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147346256","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}
Leaf senescence after harvest limits the economic value of leafy cruciferous vegetables such as Chinese flowering cabbage (Brassica rapa ssp. parachinensis). Understanding the intricate gene regulatory networks that govern postharvest leaf senescence offers potential strategies to extend the shelf-life of these vegetables. This study elucidated the regulatory networks modulating leaf senescence by utilizing time-series gene expression analysis on postharvest leaves of Chinese flowering cabbage treated with cytokinin analogue 6-benzylaminopurine and abscisic acid (ABA). ABA treatment accelerated leaf senescence, including the dismantling of chloroplasts and mitochondria, whereas 6-benzylaminopurine treatment decelerated these processes. Subsequent RNA sequencing and integrated analyses led to the construction of transcriptional regulatory networks comprising 49 transcription factors potentially regulating senescence-related pathways including reactive oxygen species (ROS) metabolism and chlorophyll degradation. Validation experiments on ROS metabolism confirmed that increased ROS accumulation paralleled the progression of leaf senescence, whereas ABA and 6-benzylaminopurine treatment resulted in opposing effects on ROS scavenging. Furthermore, exogenous ROS treatment promoted leaf senescence and the disassembly of chloroplasts and mitochondria, while ROS inhibitors delayed these processes. Further validation assays affirmed the expression patterns, transcription factor-binding capacities, and activation potentials of eight critical transcription factors and their possible target genes associated with ROS scavenging. Moreover, the role of two transcription factors (BrAGL42 and BrCRF11-2) in regulating postharvest leaf senescence and ROS scavenging ability was verified through transformation assays. Collectively, our findings shed light on the overarching transcription factor-mediated regulatory pathways in postharvest leaf senescence and indicate how cytokinin and ABA modulate this process antagonistically.
{"title":"Deciphering vital transcription factors in cytokinin- and ABA-mediated postharvest leaf senescence of Brassica rapa.","authors":"Ze-Xiang Zeng,Yuan Rong,Xiao-Lan Wang,Ya-Ting Zhao,Xin-Guo Su,Wei Wei,Wei Shan,Jian-Fei Kuang,Wang-Jin Lu,Chang-Ming Chen,Jian-Ye Chen,Lin Chen","doi":"10.1093/plphys/kiag122","DOIUrl":"https://doi.org/10.1093/plphys/kiag122","url":null,"abstract":"Leaf senescence after harvest limits the economic value of leafy cruciferous vegetables such as Chinese flowering cabbage (Brassica rapa ssp. parachinensis). Understanding the intricate gene regulatory networks that govern postharvest leaf senescence offers potential strategies to extend the shelf-life of these vegetables. This study elucidated the regulatory networks modulating leaf senescence by utilizing time-series gene expression analysis on postharvest leaves of Chinese flowering cabbage treated with cytokinin analogue 6-benzylaminopurine and abscisic acid (ABA). ABA treatment accelerated leaf senescence, including the dismantling of chloroplasts and mitochondria, whereas 6-benzylaminopurine treatment decelerated these processes. Subsequent RNA sequencing and integrated analyses led to the construction of transcriptional regulatory networks comprising 49 transcription factors potentially regulating senescence-related pathways including reactive oxygen species (ROS) metabolism and chlorophyll degradation. Validation experiments on ROS metabolism confirmed that increased ROS accumulation paralleled the progression of leaf senescence, whereas ABA and 6-benzylaminopurine treatment resulted in opposing effects on ROS scavenging. Furthermore, exogenous ROS treatment promoted leaf senescence and the disassembly of chloroplasts and mitochondria, while ROS inhibitors delayed these processes. Further validation assays affirmed the expression patterns, transcription factor-binding capacities, and activation potentials of eight critical transcription factors and their possible target genes associated with ROS scavenging. Moreover, the role of two transcription factors (BrAGL42 and BrCRF11-2) in regulating postharvest leaf senescence and ROS scavenging ability was verified through transformation assays. Collectively, our findings shed light on the overarching transcription factor-mediated regulatory pathways in postharvest leaf senescence and indicate how cytokinin and ABA modulate this process antagonistically.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"12 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147346257","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}
Chlorophyll content is a pivotal agronomic trait that directly determines photosynthetic efficiency and visual quality in tomato (Solanum lycopersicum). While positive regulators of chlorophyll biosynthesis have been extensively characterized, the mechanisms of its transcriptional repression remain less understood. Here, we report that the GRAS family transcription factor SlGRAS17 functions as a key negative regulator of chlorophyll accumulation in tomato. We isolated a high-chlorophyll mutant, hcm1, from an ethyl methanesulfonate (EMS)-mutagenized population and identified the causative lesion as a premature stop codon in SlGRAS17. Both CRISPR/Cas9-generated slgras17 mutants and the original hcm1 allele exhibited dark-green leaves with significantly elevated chlorophyll content, whereas SlGRAS17-overexpressing plants displayed a pale-green phenotype with reduced chlorophyll levels. We demonstrated that SlGRAS17 localizes to the nucleus and directly binds to a distal region of the GOLDEN-like 1 (SlGLK1) promoter to repress its transcription. Genetic evidence from virus-induced gene silencing confirmed that the high-chlorophyll phenotype of slgras17 mutants is dependent on SlGLK1. Furthermore, we elucidated that SlGRAS17 physically interacts with the transcriptional co-repressor SEUSS (SlSEU3), which in turn bridges the interaction with LEUNIG (SlLUG) in a configuration that is proposed to form a complex with repressive function. Genetic analyses revealed that SlLUG is essential for SlGRAS17-mediated repression, as loss of SlLUG abolished the repressive effect of SlGRAS17 overexpression on chlorophyll accumulation. Our study unveils a previously unidentified transcriptional regulatory module in which SlGRAS17 recruits the SlSEU3-SlLUG co-repressor complex to suppress SlGLK1 expression, thereby fine-tuning chlorophyll biosynthesis in tomato.
{"title":"SlGRAS17 negatively regulates chlorophyll biosynthesis in tomato.","authors":"Jianyong Wang,Qingfang Lin,Huizhu Yang,Zizi Meng,Yuting Jin,Lei Zhang,Zhiliang Zhang,Jing Sun,Hongyong Zhang,Yinlei Wang,Tongmin Zhao,Lei Kai,Shilian Qi","doi":"10.1093/plphys/kiag076","DOIUrl":"https://doi.org/10.1093/plphys/kiag076","url":null,"abstract":"Chlorophyll content is a pivotal agronomic trait that directly determines photosynthetic efficiency and visual quality in tomato (Solanum lycopersicum). While positive regulators of chlorophyll biosynthesis have been extensively characterized, the mechanisms of its transcriptional repression remain less understood. Here, we report that the GRAS family transcription factor SlGRAS17 functions as a key negative regulator of chlorophyll accumulation in tomato. We isolated a high-chlorophyll mutant, hcm1, from an ethyl methanesulfonate (EMS)-mutagenized population and identified the causative lesion as a premature stop codon in SlGRAS17. Both CRISPR/Cas9-generated slgras17 mutants and the original hcm1 allele exhibited dark-green leaves with significantly elevated chlorophyll content, whereas SlGRAS17-overexpressing plants displayed a pale-green phenotype with reduced chlorophyll levels. We demonstrated that SlGRAS17 localizes to the nucleus and directly binds to a distal region of the GOLDEN-like 1 (SlGLK1) promoter to repress its transcription. Genetic evidence from virus-induced gene silencing confirmed that the high-chlorophyll phenotype of slgras17 mutants is dependent on SlGLK1. Furthermore, we elucidated that SlGRAS17 physically interacts with the transcriptional co-repressor SEUSS (SlSEU3), which in turn bridges the interaction with LEUNIG (SlLUG) in a configuration that is proposed to form a complex with repressive function. Genetic analyses revealed that SlLUG is essential for SlGRAS17-mediated repression, as loss of SlLUG abolished the repressive effect of SlGRAS17 overexpression on chlorophyll accumulation. Our study unveils a previously unidentified transcriptional regulatory module in which SlGRAS17 recruits the SlSEU3-SlLUG co-repressor complex to suppress SlGLK1 expression, thereby fine-tuning chlorophyll biosynthesis in tomato.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"15 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147350682","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}
The SOS response is a widespread bacterial mechanism for coping with DNA-damaging stress. The key regulator of the process is the transcriptional repressor LexA, which represses expression of DNA-repair-related genes under non-stress conditions and undergoes self-cleavage to induce them under DNA-damaging conditions. Here, we gained insights into the SOS response and functional diversification of LexA in cyanobacteria by characterizing two model species, Synechocystis sp. PCC 6803 (S.6803) and Anabaena sp. PCC 7120 (A.7120), together with an early branching species Gloeobacter violaceus PCC 7421 (G.7421) whose LexA belongs to the same subclade as those of "Candidatus Melainabacteria". After 3 h of treatment with UV-C or UV-B, the amount of LexA in A.7120 and G.7421 decreased to 30-40% of pre-stress levels concomitant with the induction of DNA-repair-related genes, suggesting that LexA may function as a typical SOS repressor. In S.6803, on the other hand, we did not observe a decrease in LexA after treatment with UV radiation. This observation was consistent with previous studies reporting that LexA with substituted self-cleavage residues regulates expression of genes related to various cellular functions but not the SOS response in S.6803. The changes in gene expression profile of S.6803 after exposure to UV-C seemed to depend on transcription factors other than LexA, including the master regulator of photosynthetic genes, RpaB. In phototrophic cyanobacteria, the role of LexA as an SOS repressor may have become less important over the course of evolution, enabling LexA to diversify its functions in some species.
{"title":"The SOS response and functional diversification of the transcription factor LexA in cyanobacteria.","authors":"Haruka Kubodera,Hiroki Inoue,Aoi Ando,Tomoko Takahashi,Yukako Hihara","doi":"10.1093/plphys/kiag102","DOIUrl":"https://doi.org/10.1093/plphys/kiag102","url":null,"abstract":"The SOS response is a widespread bacterial mechanism for coping with DNA-damaging stress. The key regulator of the process is the transcriptional repressor LexA, which represses expression of DNA-repair-related genes under non-stress conditions and undergoes self-cleavage to induce them under DNA-damaging conditions. Here, we gained insights into the SOS response and functional diversification of LexA in cyanobacteria by characterizing two model species, Synechocystis sp. PCC 6803 (S.6803) and Anabaena sp. PCC 7120 (A.7120), together with an early branching species Gloeobacter violaceus PCC 7421 (G.7421) whose LexA belongs to the same subclade as those of \"Candidatus Melainabacteria\". After 3 h of treatment with UV-C or UV-B, the amount of LexA in A.7120 and G.7421 decreased to 30-40% of pre-stress levels concomitant with the induction of DNA-repair-related genes, suggesting that LexA may function as a typical SOS repressor. In S.6803, on the other hand, we did not observe a decrease in LexA after treatment with UV radiation. This observation was consistent with previous studies reporting that LexA with substituted self-cleavage residues regulates expression of genes related to various cellular functions but not the SOS response in S.6803. The changes in gene expression profile of S.6803 after exposure to UV-C seemed to depend on transcription factors other than LexA, including the master regulator of photosynthetic genes, RpaB. In phototrophic cyanobacteria, the role of LexA as an SOS repressor may have become less important over the course of evolution, enabling LexA to diversify its functions in some species.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"60 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147346261","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":"Inositol phosphates: small molecules with a BIG impact on maize embryo development.","authors":"Catherine P Freed, Erin Cullen","doi":"10.1093/plphys/kiag059","DOIUrl":"10.1093/plphys/kiag059","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146158082","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}
Yong-Jun He,Shuo Xu,Xin-Qin Liu,Zhi-Wen Liu,Yang Zhang,Kai-Mei Zhang,Chao Li,Chen Liu
During pollination, the dry stigma exhibits high selectivity in facilitating the hydration of pollen. Pollen Coat B-class peptides (PCP-Bs) compete with stigmatic rapid alkalinization factor peptides RALF23/33 for interaction with stigmatic receptor kinase FERONIA (FER)/ANJEA (ANJ) to promote pollen hydration. However, the molecular mechanisms underlying the FER-mediated signaling pathway involved in pollen hydration remain largely unexplored. Here, we discovered that the absence of FER in Arabidopsis (Arabidopsis thaliana) leads to alteration of actin cytoskeleton organization in stigmatic papillae and that RALF33 effectively counteracts the stigmatic actin depolymerization induced by Latrunculin B treatment. We next identified that ADF3, an actin depolymerizing factor, interacts with the cytoplasmic domain of FER. The mutant of ADF3 supported a significantly slower rate of pollen hydration compared to the wild type. Moreover, FER phosphorylated ADF3 at Thr52 and Thr94 residues in response to RALF33, repressing its actin disassembly activity and stabilizing actin organization in stigmatic papillae. Interestingly, Pollen Coat B-class peptide PCP-Bγ induced stigmatic actin remodeling via ADF3, potentially via FER, thereby facilitating pollen hydration. Taken together, this study reveals that FER-mediated signaling modulates actin cytoskeleton organization within stigmatic papillae by regulating ADF3 activity, thereby controlling stigma accessibility for pollen hydration.
{"title":"Decoding pollen hydration: the role of FERONIA-mediated signaling in stigmatic actin cytoskeleton dynamics.","authors":"Yong-Jun He,Shuo Xu,Xin-Qin Liu,Zhi-Wen Liu,Yang Zhang,Kai-Mei Zhang,Chao Li,Chen Liu","doi":"10.1093/plphys/kiag117","DOIUrl":"https://doi.org/10.1093/plphys/kiag117","url":null,"abstract":"During pollination, the dry stigma exhibits high selectivity in facilitating the hydration of pollen. Pollen Coat B-class peptides (PCP-Bs) compete with stigmatic rapid alkalinization factor peptides RALF23/33 for interaction with stigmatic receptor kinase FERONIA (FER)/ANJEA (ANJ) to promote pollen hydration. However, the molecular mechanisms underlying the FER-mediated signaling pathway involved in pollen hydration remain largely unexplored. Here, we discovered that the absence of FER in Arabidopsis (Arabidopsis thaliana) leads to alteration of actin cytoskeleton organization in stigmatic papillae and that RALF33 effectively counteracts the stigmatic actin depolymerization induced by Latrunculin B treatment. We next identified that ADF3, an actin depolymerizing factor, interacts with the cytoplasmic domain of FER. The mutant of ADF3 supported a significantly slower rate of pollen hydration compared to the wild type. Moreover, FER phosphorylated ADF3 at Thr52 and Thr94 residues in response to RALF33, repressing its actin disassembly activity and stabilizing actin organization in stigmatic papillae. Interestingly, Pollen Coat B-class peptide PCP-Bγ induced stigmatic actin remodeling via ADF3, potentially via FER, thereby facilitating pollen hydration. Taken together, this study reveals that FER-mediated signaling modulates actin cytoskeleton organization within stigmatic papillae by regulating ADF3 activity, thereby controlling stigma accessibility for pollen hydration.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"32 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147329187","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}
Nier Chen, Minghui Gao, Yongsheng Bai, Mingliang Wang, Meiting Liu, Wei Xiong, Beixin Mo
The EMBRYO DEFECTIVE 2207 (EMB2207) gene, encoding ribosomal protein UL3Z, is critical for embryonic development in Arabidopsis, with loss of function resulting in embryo lethality. Despite its importance, the role of UL3Z in the complicated protein translation machinery in plants remains poorly understood due to the lack of viable hypomorphic alleles. In this study, we utilized CRISPR/Cas9 to edit the 5' untranslated region (5'UTR) of UL3Z, generating 5 ul3z mutants with varying degrees of reduced expression levels of UL3Z proteins. The mutant with the lowest expression exhibited the most severe developmental defects. In contrast, null mutants of its paralog UL3Y displayed no observable phenotypes. Interestingly, expression of UL3Y driven by the UL3Z/EMB2207 promoter successfully rescued the phenotypes of ul3z, demonstrating that these 2 paralogous ribosomal proteins actually possess functionally interchangeable roles. GUS staining results showed that UL3Z was constitutively expressed in all examined tissues, while UL3Y was only appreciably expressed in specific tissues. Molecular analysis further revealed the accumulation of ribosomal RNA (rRNA) maturation intermediates and increased polysome levels in ul3z mutants, indicating compromised pre-rRNA processing and disturbed global mRNA translation. Interestingly, 3' ends of many rRNA precursors in ul3z had higher frequency of non-encoded tails compared with Col-0. This study demonstrates that CRISPR/Cas9-mediated 5'UTR editing is an effective tool for generating viable hypomorphic alleles of lethal genes and uncovers the critical roles of UL3Z/EMB2207 in pre-rRNA processing and the maintenance of appropriate mRNA translation on ribosomes, underscoring its importance in plant development.
{"title":"5'UTR Editing of the ribosomal protein UL3Z gene unveils its critical roles in pre-rRNA processing and global mRNA translation dynamics.","authors":"Nier Chen, Minghui Gao, Yongsheng Bai, Mingliang Wang, Meiting Liu, Wei Xiong, Beixin Mo","doi":"10.1093/plphys/kiag073","DOIUrl":"10.1093/plphys/kiag073","url":null,"abstract":"<p><p>The EMBRYO DEFECTIVE 2207 (EMB2207) gene, encoding ribosomal protein UL3Z, is critical for embryonic development in Arabidopsis, with loss of function resulting in embryo lethality. Despite its importance, the role of UL3Z in the complicated protein translation machinery in plants remains poorly understood due to the lack of viable hypomorphic alleles. In this study, we utilized CRISPR/Cas9 to edit the 5' untranslated region (5'UTR) of UL3Z, generating 5 ul3z mutants with varying degrees of reduced expression levels of UL3Z proteins. The mutant with the lowest expression exhibited the most severe developmental defects. In contrast, null mutants of its paralog UL3Y displayed no observable phenotypes. Interestingly, expression of UL3Y driven by the UL3Z/EMB2207 promoter successfully rescued the phenotypes of ul3z, demonstrating that these 2 paralogous ribosomal proteins actually possess functionally interchangeable roles. GUS staining results showed that UL3Z was constitutively expressed in all examined tissues, while UL3Y was only appreciably expressed in specific tissues. Molecular analysis further revealed the accumulation of ribosomal RNA (rRNA) maturation intermediates and increased polysome levels in ul3z mutants, indicating compromised pre-rRNA processing and disturbed global mRNA translation. Interestingly, 3' ends of many rRNA precursors in ul3z had higher frequency of non-encoded tails compared with Col-0. This study demonstrates that CRISPR/Cas9-mediated 5'UTR editing is an effective tool for generating viable hypomorphic alleles of lethal genes and uncovers the critical roles of UL3Z/EMB2207 in pre-rRNA processing and the maintenance of appropriate mRNA translation on ribosomes, underscoring its importance in plant development.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146258782","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":"One noncoding after another: a novel module against late blight in tomato.","authors":"Chong Teng","doi":"10.1093/plphys/kiag111","DOIUrl":"10.1093/plphys/kiag111","url":null,"abstract":"","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":6.9,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147309074","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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