Brandon Huntington, Anandsukeerthi Sandholu, Jun Wang, Junrui Zhang, Lingyun Zhao, Bilal M Qureshi, Umar F Shahul Hameed, Stefan T Arold
{"title":"Cryo-EM structural analyses reveal plant-specific adaptations of the CDC48 unfoldase.","authors":"Brandon Huntington, Anandsukeerthi Sandholu, Jun Wang, Junrui Zhang, Lingyun Zhao, Bilal M Qureshi, Umar F Shahul Hameed, Stefan T Arold","doi":"10.1016/j.xplc.2025.101572","DOIUrl":"https://doi.org/10.1016/j.xplc.2025.101572","url":null,"abstract":"<p><p>Targeted protein degradation through the CDC48 unfoldase enables the maintenance and rapid adaptation of proteomes across eukaryotes. However, the profound differences between animals, fungi, and plants are expected to have led to a significant adaptation of the CDC48-mediated degradation. While animal and fungal CDC48 systems have shown structural and functional preservation, such analysis is lacking for plants. We determined the structural and functional characteristics of Arabidopsis thaliana CDC48A in various states and bound to the target-identifying cofactors UFD1 and NPL4. Our analysis reveals several features that distinguish AtCDC48 from its animal and yeast counterparts, despite an 80% sequence identity. Key features are that AtCDC48A displays distinct domain dynamics and interacts differently with AtNPL4. Moreover, AtNPL4 and AtUFD1 do not form an obligate heterodimer, but AtNPL4 can independently bind to AtCDC48A and mediate target degradation; however, their joint action is synergistic. An evolutionary analysis supports that these Arabidopsis features are conserved across plants and represent the ancestral state of eukaryotic CDC48 systems. Jointly, our findings support that plant CDC48 retains a greater modular and combinatorial cofactor usage, highlighting a specific adaptation of targeted protein degradation in plants.</p>","PeriodicalId":52373,"journal":{"name":"Plant Communications","volume":" ","pages":"101572"},"PeriodicalIF":11.6,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145369333","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}
Quentin Charras Ferroussier, Charlie Mathiot, Dmitry A Semchonok, Eduard Elias, Ahmad Farhan Bhatti, Régine Lebrun, Dorian Guillemain, Marina I Siponen, Roberta Croce, Colette Jungas
{"title":"Thriving Across Seawater Depths: How Blue Light Shapes a Large PSI Supercomplex and Specific Photosynthetic Traits in the seagrass Posidonia oceanica.","authors":"Quentin Charras Ferroussier, Charlie Mathiot, Dmitry A Semchonok, Eduard Elias, Ahmad Farhan Bhatti, Régine Lebrun, Dorian Guillemain, Marina I Siponen, Roberta Croce, Colette Jungas","doi":"10.1016/j.xplc.2025.101574","DOIUrl":"https://doi.org/10.1016/j.xplc.2025.101574","url":null,"abstract":"<p><p>Seagrasses are marine flowering plants that perform oxygenic photosynthesis both under high, white sunlight and under low, blue-green light, conditions fundamentally different from those experienced by land plants. Yet, how seagrasse's photosynthetic machinery adapts to such underwater light gradient remains poorly understood. Here, we investigate the Mediterranean seagrass Posidonia oceanica, an ecosystem engineer thriving from the surface down to 40 m depth, to uncover how it maintains efficient photosynthesis across this gradient. Combining spectroscopy, pigments and blue-native PAGE analysis, we show that P. oceanica maintains a high but stable PSI/PSII ratio and constant antenna size at all depths, together with a high abundance of LHCII. Electron microscopy observation showed that the adjustment of photosynthetic efficiency along the depth gradients is achieved primarily through structural remodeling of thylakoid architecture rather than through major changes in photosystem composition. We also identify a previously undescribed large PSI supercomplex (L-PSI-LHCII) that binds an additional Lhca1-Lhca4 dimer and a phosphorylated LHCII trimer. This complex, expressed at all tested depth, is enriched in chlorophyll b, lacks the far-red absorbing chlorophylls (red-forms) typical of land plants, and exhibits distinct energy-transfer dynamics optimized for blue-light harvesting. The presence of similar PSI supercomplexes in other marine seagrasses such as Zostera marina indicates a conserved strategy among deep-growing species. Together, these results reveal how seagrasses combine structural adaptation at the level of PSI and thylakoids architecture reorganisation to sustain efficient photosynthesis and long-term carbon fixation under blue-dominated marine light.</p>","PeriodicalId":52373,"journal":{"name":"Plant Communications","volume":" ","pages":"101574"},"PeriodicalIF":11.6,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145369300","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 New Era of Bioengineered Plant NLR Receptors.","authors":"Peng Cao, Zhimao Sun, Shijie Wang, Qi Zhang, Yuyan An, Meixiang Zhang","doi":"10.1016/j.xplc.2025.101567","DOIUrl":"https://doi.org/10.1016/j.xplc.2025.101567","url":null,"abstract":"<p><p>Bioengineered plant NLR receptors are now moving toward modular design, enabling them to accurately and persistently detect a wide range of pathogens. This Commentary highlights emerging strategies for reprogramming NLRs into synthetic immune circuits, revealing a transformative concept, shifting from natural co-evolution to programmable immunity, which enhances crop resilience to evolving threats.</p>","PeriodicalId":52373,"journal":{"name":"Plant Communications","volume":" ","pages":"101567"},"PeriodicalIF":11.6,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145314112","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}
Shasha Peng, Dan Wang, Jinling Liu, Su Jiang, Yuchen Xu, Yufei Deng, Xiaolong Zhou, Fangzhi Hu, Zhuo Liu, Ye Peng, Hejun Ao, Yinghui Xiao, Jiurong Wang, Junliang Zhao, Bin Liu, Keke Yi, Lianyang Bai, Guo-Liang Wang, Houxiang Kang
{"title":"A transposon insertion into the 5' UTR of OsPT1 reprograms its expression pattern and leads to high cadmium accumulation in rice grains.","authors":"Shasha Peng, Dan Wang, Jinling Liu, Su Jiang, Yuchen Xu, Yufei Deng, Xiaolong Zhou, Fangzhi Hu, Zhuo Liu, Ye Peng, Hejun Ao, Yinghui Xiao, Jiurong Wang, Junliang Zhao, Bin Liu, Keke Yi, Lianyang Bai, Guo-Liang Wang, Houxiang Kang","doi":"10.1016/j.xplc.2025.101566","DOIUrl":"https://doi.org/10.1016/j.xplc.2025.101566","url":null,"abstract":"<p><p>Cadmium (Cd) accumulation in rice grains poses a serious threat to human health, however the underlying mechanisms remain incompletely understood. Here, we conducted a genome-wide association study and identified 29 loci associated with grain Cd content (LAGCCs). One of the top associated loci, LAGCC4, harbors the transporter gene OsPT1, whose haplotypes are tightly associated with Cd content in rice grains. A transposon, H-MITE, inserts into the 5' untranslated region of OsPT1, altering its expression pattern and leading to higher Cd accumulation. We further identified a transcription factor OsbHLH35 that specifically binds to the OsPT1<sup>H-MITE</sup> promoter to regulate its transcription in response to Cd stress. Knocking out either the OsPT1<sup>H-MITE</sup> or OsbHLH35 gene through CRISPR/Cas9 gene editing significantly reduced grain Cd content, with a reduction ranging from 61.7% to 80.6%. Our study uncovered a previously unknown mechanism responsible for high Cd accumulation in rice and identified targets for breeding rice varieties with lower Cd content.</p>","PeriodicalId":52373,"journal":{"name":"Plant Communications","volume":" ","pages":"101566"},"PeriodicalIF":11.6,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145310069","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":"Arabidopsis Leaf variegation is caused by simultaneous defects in chloroplast development and division.","authors":"Wenjuan Wu, Wei Guo, Haojie Zhu, Di Li, Zhiyi Zhang, Danni Lin, Meiying Qu, Zhenjia Yu, Jirong Huang","doi":"10.1016/j.xplc.2025.101564","DOIUrl":"https://doi.org/10.1016/j.xplc.2025.101564","url":null,"abstract":"<p><p>Chloroplast biogenesis is essential not only for photosynthesis but also for synthesis of many metabolites vital for plant growth and human nutrition. Leaf variegation provides a powerful model to dissect chloroplast biogenesis, which encompasses both chloroplast development and division. Here, we show that the Arabidopsis leaf variegation mutant var2, defective in the thylakoid protease FtsH2, exhibits severe defects in chloroplast biogenesis. Confocal and ultrastructural analyses revealed that chloroplast development is delayed yet prolonged in green sectors of var2, resulting in increased cellular heterogeneity in chloroplast number and size. Strikingly, plastid-free cells were present in white sectors, indicative of impaired chloroplast division. Consistent with this, loss of the chloroplast division factors, Paralog of Accumulation and Replication of Chloroplasts6 (PARC6) or Plastid Division1 (PDV1), exacerbated var2 variegation, whereas overexpression of PDV1 or PDV2 suppressed it. Similarly, chloroplast division is compromised in the variegated mutant immutans, and the virescent mutant clpr4 with increased chloroplast number can rescue leaf variegation of var2. Furthermore, VAR2-regulated chloroplast development and division is mediated by Constitutively Photomorphogenic1 (COP1) and autophagy-related ATG8a, respectively. Collectively, our findings reveal that leaf variegation arise from concurrent defects in chloroplast development and division, unveiling a coordinated regulatory mechanism that maintains chloroplast homeostasis.</p>","PeriodicalId":52373,"journal":{"name":"Plant Communications","volume":" ","pages":"101564"},"PeriodicalIF":11.6,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145304142","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}