{"title":"OsATG1 and OsATG8 exhibit autophagy-independent functions to oppositely regulate ROP GTPase-mediated plant immunity in rice.","authors":"Feng He, Hui Tao, Ruyi Wang, Jinling Liu, Zeyun Hao, Debao Wang, Xuetao Shi, Fan Zhang, Jiawei Long, Hao Zhang, Xiao Yang, Mengchao Qin, Shasha Peng, Chongyang Zhang, Xiaoman You, Hailong Guo, Fangfang Li, Caiji Gao, Yule Liu, Guo-Liang Wang, Yuese Ning","doi":"10.1016/j.molp.2025.07.006","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.006","url":null,"abstract":"<p><p>ROP GTPases regulate various cellular pathways, including plant immunity. Although the activation of ROP GTPases has been reported during immunity, the mechanism for dynamic deactivation of ROP GTPases remains unclear. Here, we identified the autophagy kinase OsATG1 as a key regulator that interacts with and phosphorylates RhoGAP SPIN6, which deactivates ROP GTPase OsRac1. OsATG1-mediated multi-site phosphorylation is required for SPIN6 GAP activity to hydrolyze OsRac1-GTP, and overexpression of a phosphomimic form of SPIN6 attenuates rice immunity. We further showed that two isoforms of OsATG1, OsATG1a and OsATG1b, function redundantly in rice immunity to the fungal pathogen Magnaporthe oryzae. Double mutants of OsATG1a and OsATG1b exhibit stronger resistance phenotypes, as well as developmental defects and complete sterility. To validate the association between OsATG1-mediated immunity and autophagy, we found that OsATG1 interacts with OsATG8. Phenotyping analyses of OsATG8 transgenic plants reveal that OsATG8 positively regulates rice immunity. Interestingly, OsATG8 activates immunity partially independent of its role in autophagy, as overexpressing the lipidation-defective OsATG8<sup>G117A</sup> or accumulating non-lipidated OsATG8 in the osatg7 mutant also enhances rice disease resistance. Mechanistically, OsATG8 promotes OsATG1 turnover, while OsATG8<sup>G117A</sup> is sufficient to competitively deplete OsATG1, leading to SPIN6 dissociation and degradation. As autophagy is important in nutrient recycling, we also found that nutrient limitations induce OsATG8 expression and rice immunity while suppressing SPIN6. However, SPIN6 phosphorylation blocks this nutrient limitation-induced immunity. Together, OsATG1 and OsATG8 exhibit autophagy-independent functions to convert nutrient limitation into immunity via plant-specific ROP GTPase signaling.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144708312","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}
Molecular PlantPub Date : 2025-07-23DOI: 10.1016/j.molp.2025.07.013
Lianmei Yao, Shurui Liu, Wen Shi, Yuxin Gan, Min Fan, Filip Rolland, Ming-Yi Bai, Chao Han
{"title":"Dampened Nuclear Localization of SnRK1 by Brassinosteroid Signaling Inhibits Stomatal Development in Arabidopsis.","authors":"Lianmei Yao, Shurui Liu, Wen Shi, Yuxin Gan, Min Fan, Filip Rolland, Ming-Yi Bai, Chao Han","doi":"10.1016/j.molp.2025.07.013","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.013","url":null,"abstract":"<p><p>The balance between stem cell division and differentiation is crucial for flexible organ development. In Arabidopsis leaves, the fate of meristemoids, which exhibit stem cell characteristics, is tightly regulated by multiple intrinsic developmental signals and environmental factors. KIN10, catalytic subunit of Sucrose Non-Fermenting 1 (SNF1) related protein kinase 1 (SnRK1) complex, has been shown to preferentially localize in the nucleus of meristemoids, where it phosphorylates and stabilizes SPEECHLESS transcription factor, thereby promoting stomatal development. However, the regulatory mechanism governing the nuclear localization of KIN10 in meristemoids remains unclear. Here, we demonstrate that brassinosteroid (BR) inhibits KIN10's nuclear localization by modulating KINβ2 through BIN2-mediated phosphorylation. In meristemoids, KIN10 is predominantly nuclear, while KINβ2 is mainly cytosolic. Interfering nuclear localization of KIN10 or enhancing membrane association of KINβ2 impairs stomatal development and leads to excessive epidermal cell proliferation. BR signaling could inhibit KIN10 nuclear localization through enhancing KINβ2 membrane association. BR-INSENSITIVE2 (BIN2) interacts with and phosphorylates KINβ2, which reduces its membrane association and its interaction with KIN10. These findings suggested the precise regulation of subcellular localization of SnRK1 complex, influenced by BR signaling, is critical for meristemoids differentiation and stomatal development.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144708311","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}
Molecular PlantPub Date : 2025-07-22DOI: 10.1016/j.molp.2025.07.012
Xin Su, Hong-Wei Xue
{"title":"Plant-specific casein kinases phosphorylate and stabilize SMXL6/7/8 to suppress strigolactone signaling and promote shoot branching.","authors":"Xin Su, Hong-Wei Xue","doi":"10.1016/j.molp.2025.07.012","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.012","url":null,"abstract":"<p><p>Strigolactones (SLs) significantly impact agricultural production because of their central role in regulating plant morphology. As core switch controllers of SL signaling, the transcriptional repressors SUPPRESSOR OF MAX2 1-LIKE (SMXL6/7/8) are ubiquitinated by F-box E3 ligase MORE AXILLARY GROWTH 2 (MAX2) for the 26S proteasome-mediated degradation through receptor D14. However, the post-translational modification and underlying regulatory mechanisms of SMXL6/7/8 proteins remain unknown. Here, we demonstrates that Arabidopsis seedlings deficient in or overexpressing a category of evolutionarily conserved, plant-specific protein kinase Arabidopsis EL1-like (AEL1-4) exhibit significantly reduced or increased branching, respectively. The results reveal that AEL interact with and directly phosphorylate SMXL6/7/8 proteins, inhibiting their interaction with MAX2 and thus suppressing their ubiquitination and degradation, thereby negatively interfering with SL-regulated branching. Notably, SL signaling downregulated the expression of AEL genes dependent on SMXL6/7/8 action and diminished AEL-SMXL protein interactions. This study reveals the importance of protein phosphorylation in regulating SL signaling and effects, highlighting the fine-tuning mechanism of SL signaling by the transition of SMXL6/7/8 between active and inactive forms through phosphorylation.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144699100","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}
Molecular PlantPub Date : 2025-07-17DOI: 10.1016/j.molp.2025.07.004
Léa Jacquier, Celeste Aurora Fiorenza, Kevin Robe, Jian-Pu Han, Alexandra Schmitt, Fabienne Cléard, Christelle Fuchs, Priya Ramakrishna, Sylvain Loubéry, Lothar Kalmbach, Linnka Lefebvre-Legendre, Marie Barberon
{"title":"A developmental switch controls cell-to-cell transport in roots via pectin-linked plasmodesmata changes","authors":"Léa Jacquier, Celeste Aurora Fiorenza, Kevin Robe, Jian-Pu Han, Alexandra Schmitt, Fabienne Cléard, Christelle Fuchs, Priya Ramakrishna, Sylvain Loubéry, Lothar Kalmbach, Linnka Lefebvre-Legendre, Marie Barberon","doi":"10.1016/j.molp.2025.07.004","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.004","url":null,"abstract":"Cell-to-cell communication is fundamental to multicellular life. In plants, plasmodesmata - cytoplasmic channels - enable molecular transport between adjacent cells. In roots, this transport is predicted to play a central role in nutrient acquisition and delivery across the multiple cell layers that compose the root. In this study, we demonstrate that plasmodesmatal transport persists in fully differentiated roots, despite the formation of apoplastic barriers such as Casparian strips and suberin lamellae in the endodermis. This persistence highlights plasmodesmata as a critical pathway for intercellular transport in mature roots. We also uncovered a developmental switch in plasmodesmata function: while transport is bidirectional in young roots, it becomes unidirectional towards the vasculature in differentiated roots. Through a genetic screen, we identified mutants with disrupted directionality, exhibiting persistent bidirectional transport. These mutants showed enlarged plasmodesmata apertures caused by defects in pectin composition and cell wall organization, highlighting the critical role of pectin in plasmodesmata formation and function. Our findings reveal how plasmodesmata-mediated transport is dynamically regulated during root development and provide new insights into the cellular mechanisms that govern intercellular communication in plants.","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":"13 1","pages":""},"PeriodicalIF":27.5,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664828","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":"A novel OsCRK14-OsRLCK57-MAPK signaling module activates OsbZIP66 to confer drought resistance in rice.","authors":"Tiantian Ye, Huaijun Wang, Lingqun Zhang, Xiaokai Li, Haifu Tu, Zilong Guo, Tong Gao, Yu Zhang, Ying Ye, Bingchen Li, Weiping Yang, Yibo Li, Xuelei Lai, Faming Dong, Haiyan Xiong, Lizhong Xiong","doi":"10.1016/j.molp.2025.07.011","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.011","url":null,"abstract":"<p><p>Drought stress severely limits rice productivity, making the understanding of drought response mechanisms essential for developing climate-resilient varieties. While cysteine-rich receptor-like kinases (CRKs) are primarily implicated in plant development and immunity, their role in drought response remains poorly understood. Here, we identify a cysteine-rich receptor-like kinase, OsCRK14, as a key positive regulator of drought resistance in rice. We demonstrate that plasma membrane-localized OsCRK14 phosphorylates the receptor-like cytoplasmic kinase OsRLCK57 under drought stress, initiating a MAPK cascade (OsMKKK10-OsMKK4-OsMPK6). Activated OsMPK6 directly phosphorylates the ABA-responsive transcription factor OsbZIP66 at conserved SP/TP motifs, enhancing its stability and promoting drought-responsive gene expression. Furthermore, natural variations in the OsCRK14 promoter influence its transcriptional activity by altering OsMYB72 binding affinity, correlating with drought resistance differences among rice varieties. Our study reveals a complete CRK-RLCK-MAPK-bZIP signaling pathway connecting membrane sensing to transcriptional regulation in drought response, providing both mechanistic insights and genetic resources for breeding drought-resistant rice.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144659668","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":"Fungal extracellular vesicles mediate cross-kingdom trafficking of virulence effectors into plant cells to promote infection.","authors":"Zhangying Wang, Wei Li, Guangren Kang, Jiliang Deng, Shanshan Qin, Qiang Cai","doi":"10.1016/j.molp.2025.07.009","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.009","url":null,"abstract":"<p><p>Extracellular vesicles (EVs) mediate cross-kingdom communication by delivering bioactive molecules between cells. While the role of fungal EVs in cross-kingdom RNA trafficking has been well established, whether and how they deliver pathogen-derived virulence effectors into host plants to facilitate infection remains largely unclear. Here, we report that the fungal pathogen Rhizoctonia solani secretes vesicles enriched in an EV-positive marker, RsTsp2, and two effectors, RsNP8 and RsSerp. These proteins are upregulated during the infection and are critical for the virulence of the fungus. Intriguingly, our observations reveal that clathrin-coated vesicles (CCVs) accumulate at the fungal infection sites, with the RsTsp2, RsSerp and RsNP8 detected in these vesicles, suggesting these EV-associated proteins enter plant cells via clathrin-mediated endocytosis (CME). RsNP8 was further observed in the chloroplast, where it interacts with NP8-Interacting Chloroplast Protein 1 (NICP1) in Arabidopsis. NICP1 plays a role in plant immunity by mediating the reactive oxygen species (ROS) burst during the infection, while RsNP8 suppresses this immune response. Furthermore, the silencing of RsTsp2, RsSerp, and RsNP8 in R. solani reduces sheath blight disease progression in rice plants. This work reveals that fungal EVs facilitate effectors cross-kingdom trafficking into plants, providing a novel mechanism by which eukaryotic pathogens invade their hosts.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144649972","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":"The RING-finger ubiquitin E3 ligase RFEL1 targets wheat NPR3 for degradation to confer broad-spectrum resistance against biotrophic fungal pathogens.","authors":"Liuhui Qiao, Kunpu Zhang, Jinyan Li, Ziming Zhang, Xiao Sun, Huiyun Liu, Ziyue Li, Nannan Ni, Ximei Ma, Jianhui Zhao, Guangwei Li, Xiaohuan Jin, Jibin Xiao, Wenming Zheng, Daowen Wang, Zheng Qing Fu, Huan Wang","doi":"10.1016/j.molp.2025.07.008","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.008","url":null,"abstract":"<p><p>Broad-spectrum resistance (BSR) is highly sought after for the effective management of crop diseases. However, genes suitable for developing BSR remain scarce. In this study, we demonstrate the development of BSR to wheat yellow rust (YR), powdery mildew (PM), and leaf rust (LR) diseases elicited by three biotrophic fungal pathogens using a newly defined module, namely, RFEL1-NPR3. RFEL1 is an active RING-finger E3 ubiquitin ligase identified in diploid and polyploid wheat species, which ubiquitinates and promotes the degradation of wheat NPR3 (TaNPR3), an important negative immune regulator conserved in higher plants, via the 26S proteasome system. Downregulation of TaNPR3 by either overexpressing RFEL1 or knocking out TaNPR3 confers strong resistance against four different YR races as well as the PM and LR diseases without adverse effects on wheat growth and yield traits. Notably, the enhanced disease resistance exhibited by RFEL1-overexpressing and TaNPR3-knockout lines is correlated with increased expression of defense related genes and elevated stability of NPR1 that is a pivotal positive regulator of plant immune signaling. Our findings underscore the importance of ubiquitination-dependent NPR3 degradation in plant immunity and advocate for the application of RFEL1-NPR3 module in engineering broad-spectrum resistance against biotrophic fungal pathogens in wheat and other crops.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144649973","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}
Molecular PlantPub Date : 2025-07-14DOI: 10.1016/j.molp.2025.07.007
Brian D Gregory
{"title":"Coordinated regulation of RNA metabolism and silencing by ABA signaling in plant abiotic stress responses.","authors":"Brian D Gregory","doi":"10.1016/j.molp.2025.07.007","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.007","url":null,"abstract":"","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144642988","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}
Molecular PlantPub Date : 2025-07-12DOI: 10.1016/j.molp.2025.07.005
Shanshan Zhao, Qin-Fang Chen, Li Chen, Ying Zhou, Ke Liao, Fengzhu Wang, Xue Zhang, Moxian Chen, Ruo-Han Xie, Shi Xiao
{"title":"The plant-specific protein IQD22 interacts with calcium sensors to activate anaerobic respiration during hypoxia in Arabidopsis.","authors":"Shanshan Zhao, Qin-Fang Chen, Li Chen, Ying Zhou, Ke Liao, Fengzhu Wang, Xue Zhang, Moxian Chen, Ruo-Han Xie, Shi Xiao","doi":"10.1016/j.molp.2025.07.005","DOIUrl":"https://doi.org/10.1016/j.molp.2025.07.005","url":null,"abstract":"<p><p>Louis Pasteur first reported that living cells switch from aerobic to anaerobic metabolism under low-oxygen conditions, but the underlying regulatory mechanism remains to be fully elucidated. ALCOHOL DEHYDROGENASE 1 (ADH1) encodes a key enzyme in ethanolic fermentation and is upregulated under hypoxia. Here, we searched for Arabidopsis thaliana mutants with defects in hypoxia-induced ADH1 expression. This screen identified a mutant in IQ DOMAIN containing protein 22 (IQD22). The iqd22 mutants were hypersensitive to submergence and hypoxic stress, whereas IQD22 overexpressors were more tolerant of both compared to wild type. Under hypoxia, IQD22 modulated the interaction of the calcium-dependent protein kinase CPK12 with the ERF-VII-type transcription factor RELATED TO AP2.12 (RAP2.12) to upregulate hypoxia-responsive genes, including ADH1. Moreover, IQD22 interacted with calmodulins (CaMs) in vivo and facilitated their association with ADH1, stimulating its abundance, in response to hypoxia. Metabolic profiling of the iqd22-2 mutant revealed that hypoxia caused significant increases of glycolytic metabolites, but significantly lower ethanol accumulation compared to the wild type. Furthermore, deleting ADH1 suppressed the improved hypoxia-tolerance phenotype of IQD22 overexpressors. Our findings thus demonstrate that IQD22 functions in the CaM-ADH1 and CPK12-RAP2.12 regulatory modules, which coordinately mediate calcium-dependent activation of anaerobic respiration to control metabolic flux during hypoxia.</p>","PeriodicalId":19012,"journal":{"name":"Molecular Plant","volume":" ","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144619155","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}