{"title":"SmDREB A1-10 Is Required for SmTTF30-Mediated Hypoxia Stress Tolerance in Salix matsudana.","authors":"Yanhong Chen, Mingchao Deng, Qianhui Huang, Guoyuan Liu, Jian Zhang","doi":"10.1111/pce.15442","DOIUrl":"https://doi.org/10.1111/pce.15442","url":null,"abstract":"<p><p>Frequent flooding events induced by extreme weather significantly threaten plant growth and productivity. Salix matsudana, a willow species, demonstrates exceptional tolerance to hypoxia and submergence stress, providing an ideal model for exploring underlying molecular mechanisms. This study highlights the roles of two transcriptional factors and their interplay in enhancing hypoxia and submergence stress resilience in Salix matsudana. SmTTF30, a GT-1 trihelix transcription factor, is specifically induced under root hypoxia, with its promoter enriched in hypoxia-responsive elements. Functional analyses reveal that overexpression of SmTTF30 in Arabidopsis thaliana improves submergence tolerance, whereas its downregulation in Salix matsudana results in heightened submergence stress sensitivity. SmDREB A1-10, identified through yeast one-hybrid screening and dual-luciferase assays as an upstream regulator of SmTTF30, directly interacts with its promoter. Overexpression of SmDREB A1-10 in Arabidopsis thaliana also enhances submergence tolerance, similar to SmTTF30. Virus-induced gene silencing (VIGS) experiments confirm that silencing SmDREB A1-10 diminishes SmTTF30 expression and hypoxia-responsive gene activation, exacerbating submergence stress effects. These findings unveil a regulatory cascade involving SmDREB A1-10 and SmTTF30 in submergence stress responses, providing insights into transcriptional networks governing submergence tolerance in trees.</p>","PeriodicalId":222,"journal":{"name":"Plant, Cell & Environment","volume":" ","pages":""},"PeriodicalIF":6.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481873","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}
Yonghui Miao, Chenxiao Xu, Ye Zhang, Huapeng Zhou, Qian Xu
{"title":"OsMED25-OsWRKY78 Mediated Transcriptional Activation of OsGA20ox1 Positively Regulates Plant Height in Rice.","authors":"Yonghui Miao, Chenxiao Xu, Ye Zhang, Huapeng Zhou, Qian Xu","doi":"10.1111/pce.15441","DOIUrl":"https://doi.org/10.1111/pce.15441","url":null,"abstract":"<p><p>Plant height is a crucial agronomic trait affecting lodging resistance and yield. The mediator subunit, such as MED25, plays a crucial role in regulating plant growth and development. This study elucidated the mechanistic role of OsMED25, an integral subunit of the plant mediator transcriptional coactivator complex, in the regulation of plant height. Phenotypic results indicated a significant reduction in plant height in the OsMED25-RNAi line. Further analysis indicated that GA<sub>1</sub> and GA<sub>3</sub> levels were significantly reduced, and the expression of gibberellin biosynthesis-related genes OsGA20ox1, OsGA20ox2 and OsGA20ox8 was significantly downregulated. Additionally, multiple lines of evidence supported an interaction between OsMED25 and OsWRKY78. The oswrky78 mutants exhibited significantly reduced plant height, and molecular analysis demonstrated that OsWRKY78 directly binds to the promoter region of OsGA20ox1 to activate its expression. Intriguingly, we demonstrated that OsMED25 acted as a coactivator for OsWRKY78, enhancing the transcription of OsGA20ox1. This led to elevated GA levels, positively regulating plant height. In summary, these findings demonstrated that OsMED25 played a pivotal role in regulating plant height by modulating the expression of OsGA20ox1, thereby providing a potential strategy for genetic improvement in rice.</p>","PeriodicalId":222,"journal":{"name":"Plant, Cell & Environment","volume":" ","pages":""},"PeriodicalIF":6.0,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490079","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}
Yuxin Nie, Yingying Lei, Hongbo Jiao, Zhuo Zhang, Jinxiang Yao, He Li, Hongyan Dai, Zhihong Zhang, Junxiang Zhang
{"title":"Ubiquitin-mediated degradation of the inhibitor FvMYB1 and the activator FvBBX20 by FvCSN5 balances anthocyanin biosynthesis in strawberry fruit","authors":"Yuxin Nie, Yingying Lei, Hongbo Jiao, Zhuo Zhang, Jinxiang Yao, He Li, Hongyan Dai, Zhihong Zhang, Junxiang Zhang","doi":"10.1111/tpj.70021","DOIUrl":"https://doi.org/10.1111/tpj.70021","url":null,"abstract":"<div>\u0000 \u0000 <p>Plant CSN5 is widely recognized as the subunit of the COP9 signalosome and CSN5 is mainly involved in plant growth and development, and tolerance to biotic and abiotic stresses. However, the molecular mechanism of CSN5 regulating anthocyanin biosynthesis in plants is still largely unknown. Here, we identified FvCSN5 from the woodland strawberry yeast two-hybrid library using the anthocyanin pathway inhibitor MYB1 as bait. We demonstrated the interaction of FvCSN5 and FvMYB1 by H2Y, Pull-down, LCI, and BiFC assays. FvCSN5 was expressed in all test tissues and localized in the nucleus and cytosol with self-activation activity. Stable overexpression of <i>FvCSN5</i> in woodland strawberries reduced anthocyanin accumulation in fruits. The protein level of FvMYB1 greatly decreased in overexpressing <i>FvCSN5</i> plants compared with wild-type plants. Protein degradation assay and MG-132 treatment (a proteasome inhibitor blocking 26S proteasome activity) revealed FvCSN5 degraded FvMYB1 through the ubiquitination pathway. In addition, FvCSN5 also interacted with the anthocyanin activator FvBBX20 and FvBBX20 could be degraded by FvCSN5. Moreover, transient expression analysis showed the expression of anthocyanin biosynthetic genes <i>FvCHS</i> and <i>FvF3H</i> was greatly increased and decreased when FvCSN5 was co-expressed with FvMYB1 and FvBBX20, respectively. These results indicate that FvMYB1-FvCSN5-FvBBX20 is a novel ternary complex that regulates anthocyanin biosynthesis by the ubiquitination pathway.</p>\u0000 </div>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481430","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}
TreesPub Date : 2025-02-24DOI: 10.1007/s00468-025-02613-1
Marta Nunes da Silva, Carla S. Santos, Alejandro Solla, Jordi Gamir, Victor Flors, Luis Sampedro, Rafael Zas, Marta W. Vasconcelos
{"title":"Correction to: Resistance of Pinus pinea to Bursaphelenchus xylophilus explained by the dynamic response of phytohormones, antioxidant activity, and stress-related gene expression","authors":"Marta Nunes da Silva, Carla S. Santos, Alejandro Solla, Jordi Gamir, Victor Flors, Luis Sampedro, Rafael Zas, Marta W. Vasconcelos","doi":"10.1007/s00468-025-02613-1","DOIUrl":"10.1007/s00468-025-02613-1","url":null,"abstract":"","PeriodicalId":805,"journal":{"name":"Trees","volume":"39 2","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00468-025-02613-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriele Usai, Tommaso Giordani, Alberto Vangelisti, Marco Castellacci, Samuel Simoni, Emanuele Bosi, Lucia Natali, Flavia Mascagni, Andrea Cavallini
{"title":"Haplotype-resolved genome assembly of Ficus carica L. reveals allele-specific expression in the fruit","authors":"Gabriele Usai, Tommaso Giordani, Alberto Vangelisti, Marco Castellacci, Samuel Simoni, Emanuele Bosi, Lucia Natali, Flavia Mascagni, Andrea Cavallini","doi":"10.1111/tpj.70012","DOIUrl":"https://doi.org/10.1111/tpj.70012","url":null,"abstract":"<p>In this study, we produced a haplotype-phased genome sequence of the fig tree (<i>Ficus carica</i> L.), a non-Rosaceae fruit tree model species, providing a systematic overview of the organization of a heterozygous diploid genome and, for the first time in a fruit tree, evidence of allelic expression direction-shifting among haplotypes. The genome was used for whole genome analysis of heterozygosis, allelic cytosine methylation, and expression profiles in peel and pulp fruit tissues. The two pseudo-haplotypes spanned approximately 355 and 346 Mbp, respectively, and 97% of the sequences were associated with 13 chromosome pairs of the fig tree. Overall, the methylation profile in peel and pulp tissues showed no variations between the homologous chromosomes. However, we detected differential DNA methylation within defined heterozygous allelic gene regions, particularly in upstream regions. Among 6768 heterozygous coding sequences identified, 4024 exhibited allele-specific expression, with approximately 18% specific to the peel and 14% to the pulp. Specifically, 2715 genes were consistent, with one allele always more expressed than the other in both peel and pulp. On the contrary, 22 allele-specific expressed genes switched allele expression among the fig fruit peel and pulp tissues, indicating evidence of overdominance and suggesting that the genome can express one of the two alleles higher or lower depending on developmental or environmental triggers. Notably, these genes were associated with key biological processes, including fruit maturation regulation, seed maturation, and stress response, highlighting their potential role in the plant's developmental and adaptive functions in view of gene editing-based breeding.</p>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.70012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hehe Gu, Ziyao He, Zhifeng Lu, Shipeng Liao, Yangyang Zhang, Xiaokun Li, Rihuan Cong, Tao Ren, Jianwei Lu
{"title":"Growth and survival strategies of oilseed rape (Brassica napus L.) leaves under potassium deficiency stress: trade-offs in potassium ion distribution between vacuoles and chloroplasts","authors":"Hehe Gu, Ziyao He, Zhifeng Lu, Shipeng Liao, Yangyang Zhang, Xiaokun Li, Rihuan Cong, Tao Ren, Jianwei Lu","doi":"10.1111/tpj.70009","DOIUrl":"https://doi.org/10.1111/tpj.70009","url":null,"abstract":"<div>\u0000 \u0000 <p>Potassium (K) is a prevalent limiting factor in terrestrial ecosystems, with approximately one-eighth of the world's soils undergoing K<sup>+</sup> deficiency stress. Upon encountering K<sup>+</sup> deficiency stress, leaf area (LA) declines before the net photosynthetic rate (<i>A</i><sub>n</sub>). The sequential alterations fundamentally represent the adaptive trade-off between survival and growth in plants subjected to K<sup>+</sup> deficiency stress. This trade-off is hypothesized to be linked to the differences in the subcellular distribution of limited K<sup>+</sup> resources. Thus, the K<sup>+</sup> distribution and apparent concentration in subcellular compartments, along with the LA and <i>A</i><sub>n</sub> characteristics of rapeseed leaves at various developmental stages and K<sup>+</sup> supply conditions were quantified to elucidate the mechanisms by which subcellular K<sup>+</sup> regulates leaf growth and survival. The results revealed that during the early stages of K<sup>+</sup> deficiency, leaves actively downregulate growth to sustain normal physiological functions. This is primarily accomplished by lowering the K<sup>+</sup> distribution and apparent concentration in vacuoles, restricting LA expansion, and enhancing K<sup>+</sup> distribution to chloroplasts to ensure <i>A</i><sub>n</sub>. Prolonged K<sup>+</sup> deficiency decreased the apparent K<sup>+</sup> concentration in chloroplasts below the critical threshold (37.8 m<span>m</span>), disrupting chloroplast structure and function, impairing <i>A</i><sub>n</sub>, and ultimately threatening the survival of rapeseed. Hence, sustaining an adequate concentration of K<sup>+</sup> within chloroplasts is crucial for preserving leaf photosynthetic efficiency and ensuring survival under K<sup>+</sup> deficiency stress. In conclusion, under K<sup>+</sup> deficiency stress, leaves regulate LA and <i>A</i><sub>n</sub> by trade-offs in the K<sup>+</sup> distribution between vacuoles and chloroplasts to coordinate growth and survival.</p>\u0000 </div>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481364","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}
Angela Ricono, Ella Ludwig, Anna L. Casto, Stevan Zorich, Joshua Sumner, Kevin Bird, Patrick P. Edger, Todd C. Mockler, Adrian D. Hegeman, Malia A. Gehan, Kathleen Greenham
{"title":"Homoeolog expression divergence contributes to time of day changes in transcriptomic and glucosinolate responses to prolonged water limitation in Brassica napus","authors":"Angela Ricono, Ella Ludwig, Anna L. Casto, Stevan Zorich, Joshua Sumner, Kevin Bird, Patrick P. Edger, Todd C. Mockler, Adrian D. Hegeman, Malia A. Gehan, Kathleen Greenham","doi":"10.1111/tpj.70011","DOIUrl":"https://doi.org/10.1111/tpj.70011","url":null,"abstract":"<p>Water availability is a major determinant of crop production, and rising temperatures from climate change are leading to more extreme droughts. To combat the effects of climate change on crop yields, we need to develop varieties that are more tolerant to water-limited conditions. We aimed to determine how diverse crop types (winter/spring oilseed, tuberous, and leafy) of the allopolyploid <i>Brassica napus</i>, a species that contains the economically important rapeseed oilseed crop, respond to prolonged water limitation. We exposed plants to an 80% reduction in water and assessed growth and color on a high-throughput phenotyping system over 4 weeks and ended the experiment with tissue collection for a time course transcriptomic study. We found an overall reduction in growth across cultivars but to varying degrees. Diel transcriptome analyses revealed significant accession-specific changes in time-of-day regulation of photosynthesis, carbohydrate metabolism, and sulfur metabolism. Interestingly, there was extensive variation in which homoeologs from the two parental subgenomes responded to water limitation across crop types that could be due to differences in regulatory regions in these allopolyploid lines. Follow-up experiments on select cultivars confirmed that plants maintained photosynthetic health during the prolonged water limitation while slowing growth. In two cultivars examined, we found significant time of day changes in levels of glucosinolates, sulfur- and nitrogen -rich specialized metabolites, consistent with the diel transcriptomic responses. These results suggest that these lines are adjusting their sulfur and nitrogen stores under water-limited conditions through distinct time of day regulation.</p>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.70011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elinor Aviv-Sharon, Laure D. Sultan, Leah Naveh, Meital Kupervaser, Ziv Reich, Dana Charuvi, Zach Adam
{"title":"The thylakoid lumen Deg1 protease affects non-photochemical quenching via the levels of violaxanthin de-epoxidase and PsbS","authors":"Elinor Aviv-Sharon, Laure D. Sultan, Leah Naveh, Meital Kupervaser, Ziv Reich, Dana Charuvi, Zach Adam","doi":"10.1111/tpj.17263","DOIUrl":"https://doi.org/10.1111/tpj.17263","url":null,"abstract":"<p>Non-photochemical quenching (NPQ), the dissipation of excess light energy as heat, has been long recognized as a major protective mechanism that minimizes the potential for oxidative damage to photosystem II (PSII) reaction centers. Two major positive contributors to NPQ are the carotenoid zeaxanthin, generated from violaxanthin by the enzyme violaxanthin de-epoxidase (VDE or NPQ1), and the thylakoid protein PsbS (NPQ4). The involvement of the lumenal Deg proteases in the repair of PSII from photoinhibition prompted us to further explore their possible role in other responses of <i>Arabidopsis thaliana</i> to high light. Here we show that upon exposure to high light, the single <i>deg1</i> and the triple <i>deg158</i> mutants display different levels and kinetics of NPQ, compared with the <i>deg58</i> mutant and WT that behave alike. In response to high light, the two genotypes lacking Deg1 overaccumulate NPQ1 and NPQ4. After temporal inhibition of protein translation in vivo, the level of these two proteins in <i>deg1</i> is higher than in WT. Together, the results suggest that Deg1 represents a new level of regulation of the NPQ process through adjusting the quantity of NPQ1 and NPQ4 proteins, probably through their proteolysis.</p>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.17263","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143475644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eleonora Traverso, Claudia Beraldo, Marco Armellin, Alessandro Alboresi, Tomas Morosinotto
{"title":"Flavodiiron proteins in Physcomitrium patens: navigating the edge between photoprotection and efficiency","authors":"Eleonora Traverso, Claudia Beraldo, Marco Armellin, Alessandro Alboresi, Tomas Morosinotto","doi":"10.1111/tpj.70052","DOIUrl":"https://doi.org/10.1111/tpj.70052","url":null,"abstract":"<p>Sunlight is the primary energy source for photosynthetic organisms, driving electron transport that supports the synthesis of ATP and NADPH. In dynamic environmental conditions, photosynthetic electron transport requires continuous modulation to prevent over-reduction and safeguard against potential damage. Flavodiiron proteins (FLV) contribute to photoprotection by accepting electrons downstream of Photosystem I, reducing oxygen to water. FLV were shown to have a seminal role in response to abrupt changes in illumination intensity in various photosynthetic organisms, such as cyanobacteria, green algae, mosses, and gymnosperms but were lost during evolution of angiosperms. In this work, <i>Physcomitrium patens</i> plants with strong FLV accumulation, up to 20 times higher than WT, were isolated. Overexpressor plants exhibited faster activation of electron transport but did not gain additional tolerance to light fluctuations, suggesting that the contribution to photoprotection from the FLV was already saturated in WT plants. On the contrary, strong protein overexpression caused a growth penalty under steady low or high light intensity suggesting that FLV overaccumulation can be detrimental, at least in some conditions, opening hypotheses to explain why these proteins were lost during the evolution of angiosperms.</p>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/tpj.70052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cytokinin mediates age-dependent drought response by regulating the removal reactive oxygen species in apple","authors":"Xumei Jia, Shuo Xu, Jiangtong Wei, Fei Wang, Yubin Qing, Zhijun Zhang, Tengteng Gao, Xinzhuo Mu, Changhai Liu, Ke Mao, Xiaoqing Gong, Fengwang Ma, Chao Li","doi":"10.1111/tpj.70023","DOIUrl":"https://doi.org/10.1111/tpj.70023","url":null,"abstract":"<div>\u0000 \u0000 <p>Plants exhibit age-dependent drought responses during juvenile-to-adult phase transition. However, the specific regulatory molecular mechanisms remain unknown. In this study, juvenile apple plants exhibited better drought tolerance than adult apple plants because of the age-dependent changes in root vitality, cytokinin (CK) levels, and redox status in roots. The study uncovers <i>CYTOKININ OXIDASE/DEHYDROGENASE5</i> (<i>MdCKX5</i>) as a negative regulator of drought tolerance in apple roots. Silencing of <i>MdCKX5</i> caused CK accumulation thereby enhancing drought tolerance by increasing root vitality and preventing the accumulation of reactive oxygen species. In contrast, overexpression of <i>MdCKX5</i> reduced drought tolerance in apple roots. Yeast one-hybrid, dual-luciferase and electrophoretic mobility shift assays revealed that apple transcription factor MdSPL1 directly binds to the promoters of <i>MdCKX5</i> thereby repressing its expression. Overexpression of <i>MdSPL1</i> in apple roots increased the CK content thereby enhancing drought tolerance. Further analysis revealed that MdMYB23, a positive CK-responsive gene, interacts with MdSPL1 to alleviate the repression of <i>MdCKX5</i> expression by MdSPL1. In general, drought stress significantly downregulated <i>MdMYB23</i>, thereby activating the MdSPL1-mediated repression of <i>MdCKX5</i> transcription by releasing the MdSPL1. This phenomenon led to enhanced drought tolerance in juvenile apple roots by increasing the CK levels. However, adult apple roots lost the capacity to activate this cascade. These findings provide new insights into the molecular mechanisms of CK-mediated age-dependent drought tolerance during the vegetative phase change in apples.</p>\u0000 </div>","PeriodicalId":233,"journal":{"name":"The Plant Journal","volume":"121 4","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481574","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}