Plant Physiology and Biochemistry最新文献

{"title":"A PebZIP44–PeHSF12–PeHSP17.8 transcriptional module controls heat shock protein expression and thermotolerance in passion fruit(Passiflora edulis)","authors":"Hai-bin Luo,&nbsp;Cheng-Mei Huang,&nbsp;Hui-Qing Cao,&nbsp;Run Huang,&nbsp;Meng-yun Jiang,&nbsp;Liu Yang,&nbsp;Jie Gui,&nbsp;Yuan-wen Wei","doi":"10.1016/j.plaphy.2026.111863","DOIUrl":"10.1016/j.plaphy.2026.111863","url":null,"abstract":"<div><div>Heat stress is a major constraint for passion fruit (<em>Passiflora edulis</em>) production, yet the transcriptional mechanisms underlying thermotolerance in this perennial vine remain poorly understood.This study identified 15 <em>HSF</em> genes (<em>PeHSFs</em>) in <em>Passiflora edulis</em> (<em>P</em>. <em>edulis</em>) genome. Phylogenetic analysis classified these <em>PeHSFs</em> into three distinct clusters containing 9, 4, and 2 genes, respectively, with conserved structural features supporting their functional divergence.Tissue-specific expression profiling demonstrated significant organ-dependent expression patterns of <em>PeHSFs</em> across roots, stems, leaves (young/mature), flowers, and fruits. Here, we report a heat shock transcription factor <em>PeHSF12</em>, which integrates upstream signals from a bZIP transcription factor to orchestrate downstream heat shock protein expression. Through a combination of DAP-Seq, EMSA and dual-luciferase assays, we demonstrated that <em>PeHSF12</em> directly binds to the heat shock element in the promoter of <em>PeHSP17.8</em>, a small HSP critical for protein stability under thermal stress. Crucially, we identified <em>PebZIP44</em> as an upstream transcriptional repressor of <em>PeHSF12</em>, whose expression is down-regulated under heat, thereby de-repressing <em>PeHSF12</em> and activating the heat response pathway. Functional validation using heterologous overexpression in <em>Arabidopsis</em> and virus-induced gene silencing (VIGS) in passion fruit seedlings confirmed that <em>PeHSF12</em> enhances thermotolerance through bolstering antioxidant capacity and reducing oxidative damage. This study unveils a previously uncharacterized PebZIP44–PeHSF12–PeHSP17.8 module in passion fruit, providing both mechanistic insight into heat adaptation in <em>P. edulis</em> and a candidate gene resource for breeding heat resistance cultivars.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111863"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The heat stress transcription factors HsfA3a/b enhance heat stress resistance by regulating HSP26.5-1/-2 in Sorbus pohuashanensis","authors":"Qianwen Wu,&nbsp;Xiangyu Qi,&nbsp;Zexin Di,&nbsp;Yan Zhang,&nbsp;Ruili Zhang,&nbsp;Yukuan Jin,&nbsp;Yizeng Lu,&nbsp;Yi Han,&nbsp;Jian Zheng","doi":"10.1016/j.plaphy.2026.111861","DOIUrl":"10.1016/j.plaphy.2026.111861","url":null,"abstract":"<div><div>Heat stress impacts the growth and value of ornamental plants such as <em>Sorbus pohuashanensis</em>. Heat stress transcription factors (Hsfs) and heat shock proteins (HSPs) are critical in the response of plants to heat stress. However, the roles of HsfA3a/b and HSP26.5-1/-2 in the heat tolerance mechanisms of woody plants remain elusive. Here, we report the isolation of <em>SpHsfA3a/b</em> and <em>SpHSP26.5-1/-2</em> from <em>S. pohuashanensis</em> and their molecular characterization. <em>SpHsfA3a/b</em> and <em>SpHSP26.5-1/-2</em> were expressed at higher levels in leaves and fruits. Furthermore, their expression levels increased dramatically under heat stress. Overexpression of <em>SpHsfA3a/b</em> and <em>SpHSP26.5-1/-2</em>, as well as complementation of <em>hsfa3</em> mutants with S<em>pHsfA3a/b</em> in <em>Arabidopsis thaliana</em>, significantly increased plant survival under heat stress. This enhanced survival was accompanied by reduced malondialdehyde (MDA) content, increased proline and soluble sugars, and elevated antioxidant enzyme activities. The positive regulatory genes related to the heat stress responses were upregulated, while the negative regulatory gene was downregulated in the transgenic <em>SpHsfA3a/b-</em>overexpressing <em>Arabidopsis</em> lines and the complemented <em>hsfa3</em> mutant lines under high temperature stress. Yeast one-hybrid and dual-luciferase reporter assays showed that SpHsfA3a/b directly bound to and activated the promoters of <em>SpHSP26.5-1/-2</em>. In summary, SpHsfA3a/b directly regulate the expression of <em>SpHSP26.5-1/-2</em> and play crucial, synergistic roles in enhancing thermotolerance. This study elucidates a key transcriptional regulatory module, SpHsfA3a/b–SpHSP26.5-1/-2, in the heat stress response of <em>S. pohuashanensis</em> and provides candidate genes for improving the heat resistance of forest trees.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111861"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149228628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selenium aggravates carbon-nitrogen metabolic imbalance by promoting copper uptake and translocation in apple (Malus domestica Borkh.) plants under copper stress","authors":"Chunling Liu,&nbsp;Wei Ni,&nbsp;Mengxue Lyu,&nbsp;Jingquan Liu,&nbsp;Xiuzheng Chen,&nbsp;Zhaoxia Liu,&nbsp;Ziquan Feng,&nbsp;Jie Zhou,&nbsp;Shuchong Yi,&nbsp;Yifan Bai,&nbsp;Fengying Fan,&nbsp;HanZhao Qin,&nbsp;Han Jiang,&nbsp;Zhanling Zhu,&nbsp;Jin Tang,&nbsp;Yuanmao Jiang,&nbsp;Shunfeng Ge","doi":"10.1016/j.plaphy.2026.111870","DOIUrl":"10.1016/j.plaphy.2026.111870","url":null,"abstract":"<div><div>Copper (Cu) is an essential trace element for plant growth that has concentration-dependent effects, and selenium (Se) is a beneficial element that regulates plant physiological and biochemical processes. However, the effect of Se on Cu absorption and availability remains unclear. Hydroponic experiments were conducted to determine the effects of optimal exogenous Se application on the physiological traits, Cu uptake/transport, and Cu forms of different apple organs under normal (NCu) and high Cu concentrations (HCu). Se upregulated Cu uptake-related genes (<em>COPT1</em>, <em>ZIP2</em>, and <em>ZIP4</em>) in leaves and roots under both Cu levels, promoting Cu uptake. Cu accumulation under NCu + Se and HCu + Se treatments increased by 72.7% and 41.2% compared to NCu and HCu treatments, respectively. Under NCu, Se upregulated Cu detoxification genes (<em>MT2</em>, <em>CCS</em>, and <em>CSD1</em>), downregulated transport genes (<em>HMA5</em> and <em>YSL3</em>), decreased cellular inorganic/organic Cu, and increased bound Cu, carbon and nitrogen metabolism, and the antioxidant capacity, leading to a 52.3% biomass increase. Under HCu, Se downregulated detoxification genes (<em>CCS</em> and <em>MT2</em>), increasing all Cu forms and inducing H₂O₂, O₂^∙−, and malondialdehyde accumulation. Although plants enhanced the activity of antioxidant enzymes (superoxide dismutase, catalase and peroxidase) activity and osmotic regulators (sugars, free amino acids, soluble proteins) to alleviate stress, growth-related energy was diverted, inhibiting growth. These results reveal new insights into Cu absorption and bioavailability in apple in response to Se application and provides a basis for the safe application of Se fertiliser under different soil Cu levels.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111870"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149228634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The molecular mechanism of CsWRKY24-4 and CsWRKY24-5 in response to cold stress in tea plants (Camellia sinensis)","authors":"Feixue Wu,&nbsp;Lei Yang,&nbsp;Qian Zhou,&nbsp;Nana Liu,&nbsp;Weitao Ma,&nbsp;Caiyun Li,&nbsp;Xinfu Zhang,&nbsp;Lei Zhao,&nbsp;Peiqiang Wang","doi":"10.1016/j.plaphy.2026.111819","DOIUrl":"10.1016/j.plaphy.2026.111819","url":null,"abstract":"<div><div>Cold stress has emerged as a major limiting factor for tea yield. In this study, we identified two low-temperature responsive WRKY transcription factors (CsWRKY24-4 and CsWRKY24-5) from tea plants (<em>Camellia sinensis</em>). Their expression was significantly upregulated under cold induction. Heterologous overexpression of <em>CsWRKY24-4</em> and <em>CsWRKY24-5</em> in <em>Arabidopsis thaliana</em> markedly enhanced cold tolerance in transgenic lines. Tea seedlings overexpressing <em>CsWRKY24-4</em> or <em>CsWRKY24-5</em> showed significantly stronger cold resistance under low-temperature stress, confirming their roles in enhancing cold tolerance. Yeast one-hybrid (Y1H) and dual-luciferase reporter assays demonstrated that CsWRKY24-5 directly interacts with the W-box element within the <em>CsERF061</em> promoter, whereas CsWRKY24-4 fails to bind to this motif. Moreover, overexpression of <em>CsERF061</em> in tea plants also improved the cold tolerance. Yeast two-hybrid (Y2H) and luciferase complementation assays (LCA) illustrated that CsWRKY24-4 and CsWRKY24-5 independently interact with the Squamosa promoter binding protein-like 15 (CsSPL15) transcription factor, which is also upregulated under low-temperature treatment. Taken together, our findings indicate that both CsWRKY24-4 and CsWRKY24-5 positively regulate cold stress responses in tea plants, providing valuable insights into the molecular mechanisms involved in adapt to cold conditions for tea plants.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111819"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149113861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZmNAC20 positively regulates drought tolerance in maize seedlings via a chromatin-associated network","authors":"Zhongyu Wang,&nbsp;Yating He,&nbsp;Yang Yang,&nbsp;Ning Li,&nbsp;Changyu Li","doi":"10.1016/j.plaphy.2026.111800","DOIUrl":"10.1016/j.plaphy.2026.111800","url":null,"abstract":"<div><div>The potential yield and establishment of maize are severely restricted by early developmental drought. Although NAC transcription factors are known to control abiotic stress responses, the role of NAC transcription factor 20 (<em>ZmNAC20</em>) in maize drought adaptation remains unclear. We characterized the function of <em>ZmNAC20</em> in maize seedlings using CRISPR/Cas9 mutagenesis combined with molecular, physiological, and multi-omics approaches. Loss-of-function <em>zmnac20</em> mutants displayed increased sensitivity to drought stress, indicating that <em>ZmNAC20</em> positively regulates drought tolerance in maize seedlings. Further analyses revealed that <em>NAC transcription factor 110</em> (<em>ZmNAC110</em>) functions upstream of <em>ZmNAC20</em>, activating its transcription and physically interacting with the ZmNAC20 protein. CUT&amp;Tag profiling indicated that <em>ZmNAC20</em> is associated with alterations in H3K27me3 distribution across active genomic regions. By integrating CUT&amp;Tag-seq, AI-based protein-protein interaction predictions, and RNA-seq datasets, we identified candidate downstream components associated with <em>ZmNAC20</em>. Among these, <em>YIGE1</em> was the most strongly supported candidate. <em>ZmNAC20</em> activated <em>YIGE1</em> promoter activity and interacted with the YIGE1 protein. Together, these results identify <em>ZmNAC20</em> as a positive regulator of drought tolerance in maize seedlings and identify a candidate <em>ZmNAC110</em>-<em>ZmNAC20</em>-<em>YIGE1</em> regulatory module linked to chromatin-associated drought responses. Because the genetic requirement for <em>YIGE1</em> was not tested, <em>YIGE1</em> is presented here as a strong candidate downstream component rather than a confirmed one.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111800"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149128617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CRISPR-Cas9 knockout of IBH1 fine-tunes brassinosteroid metabolism and modulates plant architecture and grain traits in durum wheat","authors":"Chiara D'Attilia,&nbsp;Marco Bonarrigo,&nbsp;Danuše Tarkowská,&nbsp;Valentina Buffagni,&nbsp;Sadiye Hayta,&nbsp;Mark A. Smedley,&nbsp;Stefania Masci,&nbsp;Samuela Palombieri,&nbsp;Francesco Sestili","doi":"10.1016/j.plaphy.2026.111831","DOIUrl":"10.1016/j.plaphy.2026.111831","url":null,"abstract":"<div><div>Brassinosteroids (BRs) are essential steroidal plant hormones that regulate cell elongation, vascular differentiation and reproductive development, thereby shaping plant architecture and grain yield. Fine-tuning BR signalling, rather than altering hormone accumulation, has been proposed as a potential strategy to regulate plant development.</div><div>Here we investigated the role of IBH1 transcription factor, a negative regulator within the ILI1/PRE1-IBH1 module controlling BR-mediated cell elongation in durum wheat (<em>Triticum turgidum</em> ssp. <em>durum</em>), using a CRISPR-Cas9-mediated knockout approach. IBH1 loss of function was associated with transcriptional changes consistent with enhanced BR signalling, including the coordinated upregulation of key signalling components (BRI1 and BZR1) and downstream regulators (ILI1 and PRE1). Metabolic profiling revealed selective remodelling of BR biosynthesis, characterized by differential accumulation of specific pathway intermediates rather than a general increase in BR content. Phenotypic analyses showed that <em>TdIBH1</em> mutants exhibited increased plant height, internode elongation, leaf inclination, grain size, and thousand grain weight, while no significant differences in fertility were detected. These findings support a role for TdIBH1 as a conserved negative regulator of BR-mediated growth in durum wheat and suggest that the manipulation of the ILI1/PRE1-IBH1 module may provide a potential strategy to modulate plant architecture and grain-related traits in cereal crops.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111831"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149137762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-length transcriptome sequencing in garlic identifies AsMYB4 as a candidate regulator of flavonoid metabolism and male sterility","authors":"Jie Ge,&nbsp;Jide Fan,&nbsp;Yongqiang Zhao,&nbsp;Xinjuan Lu,&nbsp;Canyu Liu,&nbsp;Biwei Zhang,&nbsp;Qingqing Yang,&nbsp;Mengqian Li,&nbsp;Guangyang Liu,&nbsp;Xiaohui Song,&nbsp;Yi Feng,&nbsp;Yan Yang,&nbsp;Feng Yang","doi":"10.1016/j.plaphy.2026.111804","DOIUrl":"10.1016/j.plaphy.2026.111804","url":null,"abstract":"<div><div>Garlic (<em>Allium sativum</em> L.) is crop of substantial economic value cultivated globally, yet the molecular basis underlying its reproductive development remains poorly understood. Here, we generated a comprehensive full-length garlic transcriptome using PacBio single-molecule real-time sequencing and identified 13,260 high-quality isoforms. Using this resource, we characterized <em>AsMYB4</em>, an R2R3-MYB transcription factor. Heterologous overexpression of <em>AsMYB4</em> in <em>Arabidopsis thaliana</em> repressed flavonoid biosynthesis and impaired filament elongation, reduced pollen viability, and decreased fertility without detectably affecting female reproductive function. In stamens, <em>AsMYB4</em> overexpression suppressed phenylpropanoid-flavonoid metabolism and altered auxin accumulation and signaling, supporting an association between secondary metabolism and hormonal regulation during male reproductive development. Together, these findings expand the transcriptomic resources available for garlic and identify <em>AsMYB4</em> as a candidate regulator of flavonoid metabolism and male fertility.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111804"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149143703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Haloxyfop-R-methyl resistance in Polypogon fugax: involvement of ABCG25 and ACCase gene overexpression","authors":"Jie Zhang,&nbsp;Haifang Lv,&nbsp;Yufei Zhao,&nbsp;Yikai Dong,&nbsp;Qinghua Jia,&nbsp;Renci Xiong,&nbsp;Sumei Wan,&nbsp;Wen Chen","doi":"10.1016/j.plaphy.2026.111835","DOIUrl":"10.1016/j.plaphy.2026.111835","url":null,"abstract":"<div><div>Asia minor bluegrass (<em>Polypogon fugax</em>) is a problematic grass weed in Chinese canola fields, and resistance to acetyl-CoA carboxylase (ACCase)-inhibiting herbicides is increasingly widespread. Here, we characterized a haloxyfop-R-methyl-resistant <em>P. fugax</em> population (CZ-R) collected from Chongzhou City, Sichuan Province. Whole-plant dose-response assays showed that the CZ-R population exhibited a 15.83-fold resistance level compared with the susceptible control CZ-S. Sequencing of the plastidic <em>ACCase</em> gene revealed no known target-site mutations, but <em>ACCase</em> transcript abundance was 5.55-fold higher in the CZ-R population. Pretreatment with the cytochrome P450 inhibitor malathion or the glutathione S-transferase inhibitor NBD-Cl did not reverse resistance, and LC-MS analysis showed no difference in haloxyfop-R-methyl residues between the two populations at 24 and 48 h after treatment. Screening of ABC transporter genes identified <em>ABCG25</em> and <em>ABCI19</em> as upregulated candidates in CZ-R, and heterologous overexpression in rice demonstrated that <em>ABCG25</em>, but not <em>ABCI19</em>, significantly enhanced haloxyfop-R-methyl tolerance. In addition, the resistant population showed lower H₂O₂ and malondialdehyde (MDA) levels and higher catalase (CAT) activity, accompanied by 7.13- and 5.61-fold upregulation of <em>CAT1</em> and <em>CAT2</em>, respectively. Collectively, these results indicate that haloxyfop-R-methyl resistance in the CZ-R population was not associated with known target-site mutations, while inhibitor and residue analyses did not support major P450- or GST-mediated degradation of the parent herbicide as the predominant resistance mechanism. Instead, resistance was associated with constitutive <em>ABCG25</em> and <em>ACCase</em> overexpression and with an enhanced antioxidant response characterized by higher CAT activity and reduced H₂O₂ and MDA accumulation. These findings support the coexistence of target-related and non-target-site resistance components and broaden our understanding of the diverse mechanisms underlying ACCase-inhibitor resistance in grass weeds.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111835"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149143704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-wide identification of the NAC gene family in taro and functional analysis of CeNAC48 in starch biosynthesis","authors":"Xinbi Jia,&nbsp;Ziyin Tong,&nbsp;Xinyu Wang,&nbsp;Sikandar Amanullah,&nbsp;Yufei Tang,&nbsp;Pengcheng Zeng,&nbsp;Yao Xiao,&nbsp;Qinghong Zhou,&nbsp;Qianglong Zhu","doi":"10.1016/j.plaphy.2026.111809","DOIUrl":"10.1016/j.plaphy.2026.111809","url":null,"abstract":"<div><div>Taro (<em>Colocasia esculenta</em> (L.) Schott) is an important perennial corm crop, and its corm expansion is accompanied by starch synthesis and accumulation. NAC transcription factors (TFs) serve as important regulators of plant growth and stress adaptation. However, their regulatory mechanisms underlying corm development and starch biosynthesis in taro remain largely unknown. In this study, a total of 83 NAC genes (<em>CeNACs</em>) were identified in taro. The evolution of the <em>CeNAC</em> gene family was mainly driven by segmental duplication events followed by purifying selection. Promoter cis-element analysis indicated that most <em>CeNAC</em> genes respond to light and methyl jasmonate (MeJA) signals. Transcriptomic and qRT-PCR analyses revealed that the expression of <em>CeNAC48</em> was negatively correlated with the starch accumulation in taro. <em>CeNAC48</em> was localized in the nucleus, endoplasmic reticulum and plasma membrane, and had transcriptional activation activity. Stable overexpression of <em>CeNAC48</em> in tobacco significantly decreased starch content; consistently, overexpression of <em>CeNAC48</em> in taro calli also reduced starch content, whereas silencing of <em>CeNAC48</em> resulted in starch accumulation. Yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter (LUC) assays confirmed that <em>CeNAC48</em> directly binds to the promoters of <em>CeAGPS1</em> and <em>CeBAM</em>. By repressing <em>CeAGPS1</em> and activating <em>CeBAM</em>, <em>CeNAC48</em> negatively regulates starch synthesis in taro. These findings identify <em>CeNAC48</em> as a key conserved regulator of starch biosynthesis with cross-species application potential.This study reports the first genome-wide identification of the <em>NAC</em> gene family in taro, and provides a valuable molecular target for genetic improvement of taro quality.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111809"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early humic acid-induced eustress triggers biostimulant responses in Arabidopsis thaliana: RBOHC-derived H2O2 drives growth promotion while RBOHD enables nutritional reprogramming","authors":"Álvaro Rubio,&nbsp;Maite Olaetxea,&nbsp;Javier Erro,&nbsp;Marta Fuentes,&nbsp;Angel María Zamarreño,&nbsp;José María García-Mina","doi":"10.1016/j.plaphy.2026.111790","DOIUrl":"10.1016/j.plaphy.2026.111790","url":null,"abstract":"<div><div>Root-applied humic acids (HAs) promote plant development, yet the early signaling mechanisms underlying their biostimulant action remain incompletely understood. Here, we show that treatment of <em>Arabidopsis thaliana</em> roots with a sedimentary humic acid (SHA) triggers a transient eustress-like response, characterized by early inhibition of shoot and root growth and increased H₂O₂ accumulation in root hairs and apical roots. This initial oxidative phase was followed by enhanced shoot and root growth, supporting the view that SHA acts as an adaptive plant modulator through a controlled stress-related signal. Pharmacological H₂O₂ scavenging and genetic analysis of NADPH oxidase mutants revealed that SHA-induced growth promotion depends on RBOHC/RHD2-mediated H₂O₂ production in roots. In <em>rhd2</em> plants, SHA failed to induce the characteristic H₂O₂ increase and did not promote shoot or root growth. By contrast, <em>rbohd</em> plants retained SHA-induced growth stimulation but showed impaired activation of nutrient transporter and plasma membrane H⁺-ATPase genes, limited improvement in shoot nutrient use efficiency, and partial root architectural remodeling. These results indicate that RBOHC-derived H₂O₂ is required for the growth-promoting response, whereas RBOHD cooperates with RBOHC to engage broader nutritional and developmental programs. SHA also induced extensive hormonal reprogramming in roots and shoots; however, disruption of individual ABA, auxin, jasmonate, or cytokinin signaling components did not abolish growth promotion, suggesting partially redundant hormonal regulation downstream of ROS. Overall, our findings identify an RBOHC–H₂O₂ module as a primary entry point for SHA-mediated biostimulant action and support a model in which root-localized oxidative eustress coordinates hormonal, developmental, and nutritional reprogramming in <em>Arabidopsis</em>.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111790"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}