Plant Physiology and Biochemistry最新文献

{"title":"Melatonin and auxin act synergistically to restore photosynthetic efficiency and redox homeostasis in copper-stressed Brassica juncea","authors":"Anayat Rasool Mir,&nbsp;Yamshi Arif,&nbsp;Min-Hui Bi,&nbsp;Yu-Hang Zhang,&nbsp;Di Yang,&nbsp;Lin Cai,&nbsp;Shamsul Hayat,&nbsp;Xiang-Wen Fang","doi":"10.1016/j.plaphy.2026.111849","DOIUrl":"10.1016/j.plaphy.2026.111849","url":null,"abstract":"<div><div>Copper (Cu) is an essential micronutrient involved in mitochondrial respiration, photosynthesis, and oxidative stress regulation, however, at supra-optimal concentrations it displays toxicity and inhibit plant growth and productivity. Melatonin (MT), an indoleamine with potent antioxidant activity, while as, indole-3-acetic acid (IAA), a key growth and photosynthesis promoter, both hold strong potential to mitigate abiotic stress. Considering their potential, we hypothesized that whether the antioxidant action of MT and the growth-promoting action of IAA would act synergistically or antagonistically. Results demonstrated that Cu stress enhanced the accumulation of reactive oxygen species (ROS), hydrogen peroxide (H₂O₂), superoxide (O₂⁻) malondialdehyde (MDA), and electrolyte leakage (EL) levels, thereby damaging chloroplast organization and structure, decreasing photosynthetic efficiency, CO₂ assimilation, and ultimately hinder plant growth. However, the follow-up application of IAA and/or MT proved effective in alleviating Cu-stress in plants by improving all the physio-biochemical traits via maintaining the redox homeostasis and reducing oxidative stress biomarkers. Moreover, both these indolamines proved effective to repairs the anatomical damage induced by Cu. The prominent results were obtained by combined application of both IAA and MT. The findings highlight the interplay between PGR's, antioxidant defence mechanisms and nutrient homeostasis, providing insights to develop new strategies for improving crop resilience and addressing environmental concerns associated with heavy metal accumulation in agricultural ecosystems.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111849"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149195456","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":"Aleurone layer multi-omics reveals constitutive enzyme-inhibitor imbalance in LMA-contrasting wheat cultivars","authors":"Utpal Bose,&nbsp;Angéla Juhász,&nbsp;Nicolas Daneri-Castro,&nbsp;Shoko Okada,&nbsp;James A. Broadbent,&nbsp;Keren Byrne,&nbsp;Sally Stockwell,&nbsp;Ronald Yu,&nbsp;Jean-Philippe Ral,&nbsp;Michelle L. Colgrave","doi":"10.1016/j.plaphy.2026.111757","DOIUrl":"10.1016/j.plaphy.2026.111757","url":null,"abstract":"<div><div>Late maturity amylase (LMA) is a genetic defect in wheat causing premature accumulation of high-pI alpha-amylase isoforms in the aleurone during grain development, which reduces falling number, resulting in flour downgrading and price penalties. Yet, the aleurone layer proteome and metabolome remain poorly characterised across LMA-contrasting cultivars. We measured the proteome and central carbon metabolome of aleurone from three wheat cultivars differing in LMA-phenotype: Seri (susceptible), Kennedy (intermediate), and Hartog (resistant) – under abscisic acid (ABA), abscisic acid plus gibberellic acid (GA), or untreated conditions. Cultivar identity explained 65.7% of proteome variance, exceeding hormone treatment effects (13.1%), with no significant cultivar × treatment interaction. In Seri, increased numbers and abundance of alpha-amylase isoforms, glyoxylate cycle enzymes, arabinofuranosidase, malic acid, and sucrose indicate constitutive reserve mobilisation in the absence of hormone induction. The inhibitor-to-amylase ratio was higher in Hartog than Seri, suggesting LMA susceptibility reflects a broader imbalance between degradative enzymes and their regulators rather than elevated amylase production alone. The cultivar Hartog showed higher abundance of dehydrins, invertase/PME inhibitors, and sucrose-phosphate synthase, consistent with storage maintenance and cellular protection. Multi-omics integration and proteomics-phenotype integration independently converged on the same cultivar axis, with glyoxylate cycle enzymes and arabinofuranosidase consistently associated with Seri. These findings provide a molecular framework for dissecting mechanisms of LMA susceptibility and resistance.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111757"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149075743","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":"EDAH increases bleeding sap intensity and grain yield of maize under high-density cultivation on saline-alkali soils in Xinjiang","authors":"Hongxin Wang,&nbsp;Miaomiao Zhou,&nbsp;Lan Li,&nbsp;Amanguli Aimaiti,&nbsp;Jiangge Zhang,&nbsp;Gulijiamali Tuniyazi,&nbsp;Guolong Zhao,&nbsp;Jiahao Liu,&nbsp;Bingqin Qi,&nbsp;Yunlong Zhai,&nbsp;Mingwei Du","doi":"10.1016/j.plaphy.2026.111818","DOIUrl":"10.1016/j.plaphy.2026.111818","url":null,"abstract":"<div><div>High-density maize planting compromises stalk strength and increases susceptibility to lodging. While growth regulators enhance lodging resistance and yield by optimizing stalk mechanical properties, their specific effects on the vascular structure, bleeding sap characteristics, and dry matter accumulation of ear internodes and peduncles under high plant densities remain unclear. Field experiments (2023–2024) were performed to evaluate two maize cultivars (Denghai 618, DH618; MC670) under three planting densities (90,000 plants ha⁻¹ (D1), 135,000 plants ha⁻¹ (D2), and 180,000 plants ha⁻¹ (D3)) combined with foliar-applied EDAH or a water control (CK). In 2023, under the D2 planting density, EDAH treatment significantly increased theoretical yields, with DH618 achieving a peak theoretical yield of 18.85 t ha⁻¹, a 16.2% increase compared with the control. EDAH modified vascular bundle traits by increasing the number and cross-sectional area of both pith and rind vascular bundles in ear internodes, while thickening mechanical tissues. EDAH enhanced the quantity of bleeding sap in the ear and peduncle by 11.5%–81.5% and 12.4%–70.1%, respectively, and increased bleeding sap intensity by 5.3%–24.0% and 2.8%–14.2%,while significant effects occurred in specific comparisons. Plant dry matter accumulation and its allocation to the ear also increased following EDAH application. Correlation analysis revealed significant positive associations between theoretical yield and peduncle bleeding sap intensity. Regression modeling indicated that the peduncle bleeding sap intensity and peduncle vascular bundle area contributed 54.0% to the proportion of theoretical yield variation explained in Model 2. Therefore, under high-density conditions, EDAH application improves vascular structure in ear internodes and peduncles, and modifies bleeding sap characteristics, ultimately increasing theoretical yield.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111818"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114026","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":"Calcium-mediated signaling mechanisms enhancing drought tolerance and agronomic resilience in arable crops","authors":"Christos A. Damalas","doi":"10.1016/j.plaphy.2026.111795","DOIUrl":"10.1016/j.plaphy.2026.111795","url":null,"abstract":"<div><div>Despite major advances in identifying calcium (Ca²⁺) signaling components involved in drought-tolerant crops, key challenges remain regarding how Ca²⁺ signaling interacts with abscisic acid (ABA), reactive oxygen species (ROS), and ion-transport networks. This review synthesized evidence from studies published between 1998 and 2026 on Ca²⁺-mediated drought tolerance mechanisms in arable crops. Evidence was evaluated from studies on membrane stability and ABA responses to multi-omics investigations of kinase regulation and stress-signaling integration. Studies included cereal (maize, rice, wheat), fiber (cotton), oilseed (canola), legume (faba bean), and horticultural (tomato) crops, with maize and rice being the most extensively studied species. The synthesis identified Ca²⁺ signaling as a key regulator of drought adaptation, driven predominantly by kinase-mediated pathways, with more limited evidence linking Ca²⁺/calmodulin signaling and ion-channel regulation to coordinated physiological processes. Drought-tolerance mechanisms included ABA-mediated stomatal closure, ion transport regulation, ROS detoxification, antioxidant activation, osmotic adaptation, and stress-responsive gene expression. ABA-mediated stomatal regulation was the most consistently supported mechanism, ROS-linked responses showed association without clear causality, and ion-channel regulation and stress-memory responses remain underexplored. These processes may contribute to improved water-use efficiency, antioxidant protection, membrane stability, and yield maintenance under drought conditions. In addition, agronomic practices that enhance calcium availability may support drought resilience under field conditions, though the underlying molecular link remains unproven. Thus, integrated management strategies, including soil amendments, foliar sprays, and irrigation, may help improve drought tolerance in crops. Future research should emphasize genome editing, multi-omics integration, field validation, and molecular breeding to develop climate-resilient crop cultivars.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111795"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114105","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":"Heat priming improves spikelet fertility and seed germination under heat stress with proteomic changes in IR64 (Oryza sativa L.)","authors":"Young-Hwan Ju,&nbsp;Ju-Young Choi,&nbsp;Sung-Ho Yun,&nbsp;Jun-Ichi Sakagami","doi":"10.1016/j.plaphy.2026.111766","DOIUrl":"10.1016/j.plaphy.2026.111766","url":null,"abstract":"<div><div>Heat stress during the reproductive stage severely impairs spikelet fertility and can negatively affect subsequent seed germination in rice. Heat priming has been proposed as an effective strategy to mitigate heat stress; however, its effects depending on the timing of application and the associated protein-level responses remain insufficiently understood. In this study, heat priming was applied to the heat-sensitive rice cultivar IR64 at the tillering and booting stages, followed by heat stress at the flowering stage, to evaluate its effects on growth, reproductive traits, and progeny seed germination, together with associated proteomic changes. Heat stress significantly reduced spikelet fertility and delayed progeny germination. In contrast, heat-primed plants showed higher spikelet fertility and faster germination than non-primed plants under heat stress conditions. Under the present experimental conditions, tillering-stage priming showed greater improvements in these traits than booting-stage priming. Proteomic analysis revealed distinct protein abundance patterns between heat-primed and non-primed plants under heat stress, with a higher number of differentially abundant proteins observed following tillering-stage priming. The identified proteins were mainly associated with stress response and redox homeostasis, carbon metabolism and energy allocation, and protein synthesis and cellular regulation. The differences between the two priming treatments may reflect the combined effects of developmental stage and the priming-to-stress interval. Overall, these findings indicate that heat priming modified reproductive and progeny germination responses to subsequent heat stress in IR64 and was associated with changes across multiple protein functional categories.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111766"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149114306","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":"Dynamic transcriptomic profiling of Salix triandra under freezing stress identifies StWRKY31 as a positive regulator of cold tolerance","authors":"Chang Jia,&nbsp;Yingnan Chen,&nbsp;Tongming Yin","doi":"10.1016/j.plaphy.2026.111846","DOIUrl":"10.1016/j.plaphy.2026.111846","url":null,"abstract":"<div><div><em>Salix triandra</em> is a fast-growing shrub willow native to temperate and cold regions, possessing remarkable freezing tolerance. However, the molecular mechanisms underlying this natural cold hardiness remain largely unexplored. In this study, we performed a time-course transcriptomic analysis of <em>S. triandra</em> seedlings subjected to freezing stress at −4 °C. A total of 11,287 differentially expressed genes were identified and clustered into six distinct co-expression modules with dynamic temporal patterns, revealing a multi-phasic transcriptional response involving early stress perception, metabolic adjustment, and sustained cellular protection. Among the differentially expressed transcription factors, a WRKY family member designated <em>StWRKY31</em> (<em>EVM0008367</em>) was identified as a cold-induced candidate gene, belonging to a mid-to-late adaptation module peaking at 24 h. Subcellular localization analysis showed that StWRKY31 localizes to the nucleus. Heterologous overexpression of <em>StWRKY31</em> in <em>Arabidopsis</em> significantly enhanced freezing tolerance, as evidenced by improved survival rates under both non-acclimated and cold-acclimated freezing assays. In the <em>StWRKY31</em>-overexpressing <em>Arabidopsis</em> lines, reactive oxygen species (ROS) accumulation was reduced, superoxide dismutase (SOD) and peroxidase (POD) activities were increased, proline content was elevated, and malondialdehyde (MDA) levels were decreased. Moreover, <em>StWRKY31</em> upregulated the expression of cold-responsive marker genes (<em>AtGSTF8</em>, <em>AtZAT10</em>, and <em>AtHY5</em>) in a time-dependent manner, with elevated basal expression prior to cold exposure, suggesting a potential defense priming state. These findings suggest that <em>StWRKY31</em> functions as a positive regulator of freezing tolerance. This study contributes to understanding the regulatory dynamics of cold adaptation in woody plants and provides a valuable candidate gene for breeding cold-tolerant varieties.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111846"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205104","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":"Photooxidation in interveinal tissues of magnesium-deficient leaves is associated with sugar accumulation","authors":"Xiaolei Ye,&nbsp;Ke Xu,&nbsp;Cheng Yang,&nbsp;Bo Liao,&nbsp;Binglin Li,&nbsp;Tao Ren,&nbsp;Zhifeng Lu,&nbsp;Jianwei Lu","doi":"10.1016/j.plaphy.2026.111814","DOIUrl":"10.1016/j.plaphy.2026.111814","url":null,"abstract":"<div><div>Magnesium (Mg) deficiency often leads to leaf photooxidation, typically manifested as interveinal chlorosis. This symptom arises from an imbalance between light energy absorption and its utilization, resulting in excessive excitation energy, reactive oxygen species (ROS) accumulation and subsequent photodamage. However, the spatial heterogeneity of Mg deficiency responses within a leaf remains poorly understood, particularly the physiological basis for the greater severity of photooxidation in interveinal tissues compared with vein-adjacent areas. Here, a hydroponic culture system was employed to investigate tissue-specific responses of rapeseed (<em>Brassica napus</em> L.) leaves to varying Mg supply levels. Mg deficiency significantly inhibited leaf growth, with symptoms increasing as leaves aged. Interveinal tissues exhibited pronounced chlorosis, elevated ROS accumulation, and a sharp decline in photosynthetic capacity relative to vein-adjacent tissues. Despite comparable Mg concentrations between the two leaf regions, interveinal tissues accumulated significantly higher levels of soluble sugars under Mg deficiency, suggesting that localized carbohydrate accumulation may contribute to their greater susceptibility to oxidative stress. To further test this hypothesis, a complementary experiment showed that foliar application of fructose markedly aggravated chlorosis in Mg-deficient leaves, providing direct evidence that leaf yellowing is closely associated with carbohydrate accumulation. To elucidate the underlying mechanisms, further analyses revealed that Mg deficiency suppressed the expression of sugar transporter genes, reduced Mg²⁺-ATPase activity, and decreased vascular bundle area, with these effects being particularly pronounced in interveinal tissues. These changes likely impair phloem loading and carbohydrate translocation, leading to localized sugar retention in interveinal regions. Collectively, our results indicate that Mg deficiency disrupts sugar transport and vascular function, resulting in carbohydrate accumulation that intensifies photooxidative stress and ultimately drives the development of interveinal chlorosis.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111814"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149167966","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":"Natural regulatory variations of MdIAA14b links auxin signalling to fruit cell density and firmness in apple","authors":"Hussain Ahmed,&nbsp;Zhiyong Wu,&nbsp;Md Marufur Rahman,&nbsp;Zhe Zhou,&nbsp;Yarong Wang,&nbsp;Chunyan Wang,&nbsp;Zhenli Yan,&nbsp;Qiming Gao,&nbsp;Zhenzhen Liu,&nbsp;Yaru Zhang,&nbsp;Xiangpeng Meng,&nbsp;Yiru Yang,&nbsp;Xiuhua Gao,&nbsp;Tianyu Wu,&nbsp;Hengtao Zhang,&nbsp;Jia-Long Yao","doi":"10.1016/j.plaphy.2026.111852","DOIUrl":"10.1016/j.plaphy.2026.111852","url":null,"abstract":"<div><div>Fruit firmness is a major determinant of apple quality and shelf life. It is known to be regulated by ethylene signalling, however, the function of auxin in it is not known. Here, we identified <em>MdIAA14b</em>, an auxin-responsive gene, as a key regulator of apple fruit firmness. <em>MdIAA14b</em> showed allele-specific expression (ASE) across multiple apple cultivars and developmental stages as revealed by RNA-seq analysis. Relative to the low expression allele, the promoter of the high expression allele contained two insertions of 9 bp and 1636 bp. The 9-bp insertion generated an ARF-binding site that enabled activation by the transcription factor <em>MdARF1</em>. The 1636-bp insert, identified as a transposable element (TE), disrupted and reduced the expression of a long non-coding RNA (<em>lncRNA_iaa14b</em>), which exhibited an inverse expression pattern relative to <em>MdIAA14b.</em> Apple cultivars homozygous for the high-expression allele displayed increased cell density, smaller cell size, and firmer fruit, whereas those homozygous for the low-expression allele had larger cells and softer fruit. <em>MdIAA14b</em> overexpression in tomato increased cell number and enhanced fruit firmness. Furthermore, <em>MdIAA14b</em> overexpression altered the expression of auxin-responsive genes, including members of ARF, SAUR, and GH3 families, which may relate to increased cell division. Together, these findings reveal that naturally occurring cis-regulatory variations control <em>MdIAA14b</em> expression and, consequently, apple fruit firmness. This work provides a molecular framework for improving fruit texture and highlights the role of cis-regulatory variation in allele-specific gene regulation in perennial fruit crops.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":"239 ","pages":"Article 111852"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149184096","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}