Plant Science最新文献

{"title":"CML23 mediates NO induced Ca2+ signaling during hypocotyl elongation in Arabidopsis","authors":"Dongsheng Wang,&nbsp;Xiaoduo Zhang,&nbsp;Yueyue Qiao,&nbsp;Weizhong Liu","doi":"10.1016/j.plantsci.2025.112619","DOIUrl":"10.1016/j.plantsci.2025.112619","url":null,"abstract":"<div><div>Calcium ions (Ca²⁺) play essential roles in plants, serving as both structural elements in cells and critical secondary messengers that influence growth, development, and stress adaptation. Similarly, nitric oxide (NO), a gaseous signaling molecule widespread in living organisms, participates in the regulation of diverse plant physiological processes. These two signaling molecules engage in a bidirectional interaction network, yet the molecular basis of their crosstalk remains largely unclear. Our earlier RNA-seq analysis revealed that <em>CML23</em> expression in Arabidopsis seedlings is modulated by exogenous NO, leading us to propose that NO might suppress hypocotyl elongation by activating Ca²⁺ signaling through CML23. To investigate this hypothesis, we utilized Arabidopsis as a model system and combined genetic, biochemical, and molecular biology approaches to explore CML23's function in NO-mediated hypocotyl growth inhibition. Results showed that NO treatment strongly inhibited hypocotyl elongation in wild-type but had minimal effect in <em>cml23</em> mutant. NO exposure induced post-translational <em>S</em>-nitrosylation and affected Ca²⁺-binding ability of CML23. Additionally, cytoplasmic Ca²⁺ levels in <em>cml23</em> displayed diminished responsiveness to NO compared to the wild type. Transcriptomic profiling further indicated that CML23 contributes to the integration of NO-Ca²⁺ signaling with light and phytohormone pathways. This study enhances our comprehension of the NO-Ca²⁺ interaction network in plants.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112619"},"PeriodicalIF":4.2,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Compromised function of ARM, the interactor of Arabidopsis telomerase, suggests its role in stress responses\" [Plant Sci. 325 (2022) 111453].","authors":"Klára Přikrylová Konečná, Agata Kilar, Petra Kováčiková, Jiří Fajkus, Eva Sýkorová, Miloslava Fojtová","doi":"10.1016/j.plantsci.2025.112614","DOIUrl":"https://doi.org/10.1016/j.plantsci.2025.112614","url":null,"abstract":"","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":" ","pages":"112614"},"PeriodicalIF":4.2,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CsAHL20 negatively regulates epi-catechins biosynthesis under drought stress in Camellia sinensis","authors":"Yu Chen ,&nbsp;Mingyuan Luo ,&nbsp;Ping Li ,&nbsp;Qi Zhao ,&nbsp;Luo Chao ,&nbsp;Yujie Jiao ,&nbsp;Shiyu Tian ,&nbsp;Xingyu Tian ,&nbsp;Shenyuan Ye ,&nbsp;Zhenkedai Yuan ,&nbsp;Yilan Hu ,&nbsp;Yongqing Bai ,&nbsp;Yue Wan ,&nbsp;Dejun Wang ,&nbsp;Wenyuan Chen ,&nbsp;Xinzhuan Yao ,&nbsp;Litang Lu","doi":"10.1016/j.plantsci.2025.112613","DOIUrl":"10.1016/j.plantsci.2025.112613","url":null,"abstract":"<div><div>Catechins are an integral part of the beneficial compound profile of the tea, and their biosynthesis critically responds to several biotic and abiotic factors. Drought is one of the important abiotic factors affecting their biosynthesis. The molecular mechanism of their biosynthesis during drought stress remains unclear. A transcription factor, <em>AHL</em>, strongly responds to drought stress, and its exploration in tea plants could unveil the drought-associated mechanism of catechin biosynthesis. The results of <em>CsAHL</em> gene family identification and drought transcriptome data of tea plants marked a transcription factor, <em>CsAHL20</em>, possessing an AT-hook motif and the nucleus as its locality. This transcription factor was significantly up-regulated under drought and had a significant negative correlation with <em>epi</em>-catechins content. After overexpression of <em>CsAHL20</em>, the <em>epi</em>-catechins’ biosynthesis key gene, <em>CsANR</em>, was significantly down-regulated along with significantly reduced <em>epi</em>-catechin contents. On the contrary, after silencing <em>CsAHL20</em>, <em>CsANR</em> was up-regulated, and <em>epi</em>-catechin contents were increased significantly. The dual-luciferase reporter assay and electrophoretic mobility shift assay showed that <em>CsAHL20</em> could bind to the promoter of <em>CsANR</em> and inhibit its transcription. This study revealed that <em>CsAHL20</em> inhibited the transcription of <em>CsANR</em>, thereby negatively regulating the <em>epi</em>-catechins biosynthesis under drought, which laid a foundation for improving the quality of tea.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112613"},"PeriodicalIF":4.2,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exogenous abscisic acid application enhances nitrogen use efficiency and root development in rapeseed: Transcriptomic and morphological evidence","authors":"Atif Ayub ,&nbsp;Airish Nayab ,&nbsp;Nan Yunyou ,&nbsp;Xie Yuyu ,&nbsp;Shi Derong ,&nbsp;Temoor Ahmed ,&nbsp;Tian Hui ,&nbsp;Hui Jing ,&nbsp;Gao Yajun","doi":"10.1016/j.plantsci.2025.112610","DOIUrl":"10.1016/j.plantsci.2025.112610","url":null,"abstract":"<div><div>Nitrogen (N) is an essential macronutrient governing plant growth and development. However, its excessive application in agricultural systems has precipitated environmental degradation while simultaneously reducing nitrogen use efficiency in crops. This study examined the effects of abscisic acid (ABA; 50 μM) under both high nitrogen (7.5 mM NO₃⁻) and low nitrogen (0.25 mM NO₃⁻) conditions on the roots system of rapeseed (<em>Brassica napus</em>) using a hydroponic system. Exogenous ABA application significantly enhanced root morphological parameters (root fresh weight by 16 %, total root length by 7 %, root surface area by 5 %, root dry weight by 16 %, and root volume by 24 %), substantially increased nitrogen concentration (30 %), and upregulated the activities of key nitrogen assimilation enzymes including nitrate reductase (18 %), nitrite reductase (17.8 %), glutamine synthetase (49 %), and glutamate synthase (10 %). Additionally, ABA application enhanced the activities of antioxidant enzymes including peroxidase (30 %), catalase (11 %), ascorbate peroxidase (29 %), and superoxide dismutase (25 %), while simultaneously increasing endogenous phytohormone concentrations of abscisic acid (30.4 %), indole-3-acetic acid (64.9 %), salicylic acid (72.9 %), and jasmonic acid (90.3 %) under low nitrogen (LN) stress conditions. Additionally, transcriptomic analysis explored the differentially expressed genes (DEG) significantly associated with antioxidant enzymes, nitrogen metabolism, transcription factors from the bZIP, AP2/ERF, and MYB families, as well as endogenous hormones including ABA signaling components (<em>PYL/PYR/RCAR, PP2C, SnRK2</em>). Overall, our findings establish a mechanistic foundation for enhancing nitrogen use efficiency (NUE) in Brassica napus through targeted molecular approaches such as CRISPR-Cas9 gene editing or transgenic overexpression, thereby contributing to the advancement of sustainable agricultural practices.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112610"},"PeriodicalIF":4.2,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seed germination compromises expansion pressure, cell wall alterations, and the cuticular layer: New insights.","authors":"Angel J Matilla","doi":"10.1016/j.plantsci.2025.112612","DOIUrl":"https://doi.org/10.1016/j.plantsci.2025.112612","url":null,"abstract":"<p><p>The seed is a complex structure composed of different functional tissues that interact to ensure successfull germination. This organization supports embryo protrusion and its transition from heterotrophic to photoautotrophic growth. During germination, the seed reactivates its genome, and embryo cells undergo changes through distinct transcriptional states. Once germination is triggered, endosperm expansion occurs, driven by the growing embryonic axis, though the exact mechanism remains unknown. The GA/DELLA-NAC25/NAC1L-AtEXP2 module is essential for regulating endosperm expansion under high-gibberellin (GA) conditions, thereby supporting germination. The mechanical anisotropy of the cell wall (CW) governs the direction of expansion, a process that involves the alignment of microtubules. The expansion process, along with the induction of more deformable CWs through CW remodeling enzymes (CWRE), creates an interplay of dormacy-related mechanical forces that facilitate in seed-coat rupture and \"sensu stricto\" germination. Abscisic acid (ABA) levels and signaling sharply decrease at the onset of germination; however, the regulatory mechanisms underlying the loss of ABA sensitivity remain unclear. Recently, MBF1 family genes have been shown to regulate ABA and GA levels at the onset of seed germination. In endosperm seeds, endosperm and seed-coat ruptures must be overcome for successful germination. In contrast, during monocot germination, the coleorhiza first penetrates the surrounding structures, followed by the emergence of the radicle. The presence of a cuticle (CU) associated with the endosperm plays a key role throughout the seed's life, particularlly during the onset of germination, by controlling endosperm permeability through tannic CWs attached to it. This recently discovered layer relies on two receptor-like kinases, GSO1 and GSO2, as well as the peptides CIF2 and PSY1 from the endosperm. However, it remains unclear whether the CU tissue softens or alters its structure to facilitate radicle protrusion. In summary, this review highlights recent advances in the understanding of seed germination, with a focus on its molecular regulation, biomechanical properties, and inter-tissue communication. To conclude, these insights underscore the CU as a dynamic and multifunctional barrier that adapts to developmental cues, ensuring its dual role in seed protection during dormancy and facilitating a controlled transition to growth.</p>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":" ","pages":"112612"},"PeriodicalIF":4.2,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel cotton miR7814 targeting GhCNL2 regulates plant defense against Verticillium dahliae infection","authors":"Lin Xu ,&nbsp;Ye Tang ,&nbsp;Ge Zhao ,&nbsp;Zhennan Zhang ,&nbsp;Xiaoqiong Zhang ,&nbsp;Wenwen Liu ,&nbsp;Qingzhong Peng ,&nbsp;Jiahe Wu","doi":"10.1016/j.plantsci.2025.112604","DOIUrl":"10.1016/j.plantsci.2025.112604","url":null,"abstract":"<div><div>Many miRNAs can post-transcriptionally regulate expression levels of a type of resistant (R) genes encoding NBS-LRR proteins. However, the underlying resistant mechanisms of various miRNAs-targeted R gene pairs remain explored. Here, we addressed a novel ghr-miR7814 targeting <em>GhCNL2</em> function in plant resistance against <em>Verticillium dahliae</em> infection. Based on GUS reporter and 5’-RLM RACE analyses, ghr-miR7814 was revealed to directedly target <em>GhCNL2</em> mRNA for cleavage through post-transcriptional process. Through virus-induced gene silencing (VIGS) or overexpressing assays, we found that ghr-miR7814 knockdown significantly increased plant resistance to pathogen infection, whereas ghr-miR7814 overexpression and <em>GhCNL2</em> knockdown significantly reduced plant resistance, which was accompanied by expression changes of defense-related genes including <em>GhPR1</em>, <em>GhPR3</em>, <em>GhPR5</em> and <em>GhPDF1.2</em>. Results of DAB staining revealed that H₂O₂ contents in <em>GhCNL2</em> knockdown plants were significantly higher than those in the control. The expression levels of SA biosynthesis-related genes including <em>GhICS1</em>, <em>GhEDS1</em> and <em>GhPAD4</em> showed significant differences between <em>GhCNL2</em> knockdown and the control plants under <em>V. dahliae</em> infection as well as SA accumulation. Taken together, these results demonstrated that the novel ghr-miR7814 targeting <em>GhCNL2</em> is able to regulate plant resistance to <em>V. dahliae</em> infection possibly via induction of ROS and SA biosynthesis.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112604"},"PeriodicalIF":4.2,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-anthesis phosphorus sprays boost reproductive development and seed yield in heat-stressed Phaseolus vulgaris L.","authors":"Matheus D. Laira ,&nbsp;Diego da S. Graciano ,&nbsp;Sara A.L. Andrade ,&nbsp;Fernando C.B. Zambrosi ,&nbsp;Rafael V. Ribeiro","doi":"10.1016/j.plantsci.2025.112611","DOIUrl":"10.1016/j.plantsci.2025.112611","url":null,"abstract":"<div><div>Climate change intensifies heat waves, threatening global food security. Common bean (<em>Phaseolus vulgaris</em> L.) is highly sensitive to heat waves during flowering, which disrupts source-sink relationships, reduces pollen viability, and diminishes seed yield. Phosphorus (P) deficiency further limits carbohydrate transport to reproductive tissues during heat waves. This study evaluated the efficacy of leaf P spraying in mitigating heat wave effects in common bean plants facing P deficiency (PD) and P sufficiency (PS) during flowering, i.e., phenological phases V4 to R6. A complete factorial experiment evaluated two substrate P availability during flowering (PD and PS), two leaf P spraying treatments applied during the pre-anthesis (without P spraying, -P; and with P spraying, +P), and two air temperature regimes during flowering: control (28/18 °C, day/night) and heat wave (38/28 °C, day/night). Preventive leaf P spraying improved photochemical efficiency, reduced oxidative stress, and avoided decreases in photosynthetic pigment content under heat wave. P-sprayed plants exhibited greater starch deposition in pollen grains and higher soluble carbohydrate concentration, showing less cellular damage caused by heat wave. As a result, leaf P spraying also increased seed yield under heat wave by sustaining pollen viability owing to improved supply of soluble carbohydrates to reproductive structures. These findings underscore the critical role of leaf P spraying in alleviating heat wave and impaired P acquisition in common bean during flowering by enhancing reproductive resilience and yield stability. This study highlights the potential of such a strategy of preventive leaf P spraying at critical phenological phases to improve crop performance under heat wave conditions caused by climate change.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112611"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dark-induced decrease in ascorbate levels in Arabidopsis leaves occurs independently of ascorbate peroxidase and oxidase, recycling enzymes, and senescence signaling","authors":"Tamami Hamada ,&nbsp;Kojiro Yamamoto ,&nbsp;Akane Hamada ,&nbsp;Takanori Maruta","doi":"10.1016/j.plantsci.2025.112608","DOIUrl":"10.1016/j.plantsci.2025.112608","url":null,"abstract":"<div><div>Ascorbate is a key antioxidant that protects plant cells from oxidative damage. While plants actively synthesize ascorbate during the day, its degradation becomes prominent under prolonged dark conditions. Since ascorbate degradation begins with its oxidized form, dehydroascorbate (DHA), this process inherently requires ascorbate oxidation. However, the molecular mechanisms underlying dark-induced ascorbate oxidation and subsequent degradation remain unclear. In this study, we investigated the role of intracellular and extracellular ascorbate redox regulation in controlling this process. Using Arabidopsis knockout mutants for key enzymes involved in ascorbate oxidation and recycling, including ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR), and ascorbate oxidase (AO), as well as NADPH oxidases (rbohD and rbohF), we found that none of these enzymes significantly influenced the dark-induced decrease in ascorbate levels. Notably, ascorbate levels decreased similarly in newly generated multiple mutants, including a quintuple mutant (∆<em>dhar pad2 mdar5</em>), which has severely impaired ascorbate recycling capacity, and the <em>ao2 rbohD</em> double mutant, which is strongly expected to exhibit a highly altered apoplastic redox state. Furthermore, we examined the potential involvement of senescence signaling, including ORESARA1 and ethylene signaling components, but found no evidence for their contribution. These findings indicate that the dark-induced decrease in ascorbate levels is not governed by conventional pathways for ascorbate oxidation and recycling or senescence signaling processes, suggesting an unidentified regulatory mechanism.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112608"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144294808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Putrescine attenuates heat stress by modulating membrane stability, antioxidant activity, and gaseous exchange in Brassica juncea L.","authors":"Parul Sharma ,&nbsp;Nita Lakra ,&nbsp;Annu Luhach ,&nbsp;Abbu Zaid ,&nbsp;Kadambot H.M. Siddique","doi":"10.1016/j.plantsci.2025.112609","DOIUrl":"10.1016/j.plantsci.2025.112609","url":null,"abstract":"<div><div>Rising temperatures severely stress plant growth and development by disrupting metabolic processes. Indian mustard (<em>Brassica juncea</em> L.) faces extreme temperatures during various growth phases. Early-sown <em>Brassica</em> encounter heat stress during germination and vegetative phases, while late-sown suffer higher yield losses due to increased evaporative demand during the reproductive stage, leading to faster maturation, increased senescence, and reduced productivity. Polyamines (PAs), small positively charged nitrogenous compounds, play important roles in plant growth and stress responses. Putrescine (Put), a key PA, is known to enhance plant growth and provide tolerance from stresses. This research aimed to explore how Put (1 mM) mitigates heat stress effects on early, timely, and late-sown genotypes RH-1707, RH-1708 (heat-sensitive), and RH-1566 and RH-1999–42 (heat-tolerant). RH-1999–42 showed the highest tolerance under early heat stress, while RH-1708 was the most sensitive. Conversely, RH-1707 experienced significant losses under late heat stress, whereas RH-1566 displayed tolerance under both early and late heat stress.Exogenous application of Put alleviated heat stress by reducing lipid peroxidation, hydrogen peroxide, electrolyte leakage, transpiration rate, stomatal conductance, and stomatal density, while boosting antioxidant enzyme activities, chlorophyll content, relative water content, proline content and overall yield. The most significant benefits were observed in RH-1707 and RH-1708, which were higher susceptible to cellular damage under heat stress. Anatomical examinations revealed enlarged xylem vessels in RH-1707 and RH-1708 under early sowing, while late-sown plants showed less developed vessels. Put application partially reduced vessel size under early heat stress, though its effects were minimal during late heat stress. This study demonstrated that 1 mM Put foliar spray effectively mitigates the harmful effects of heat stress at early and late-sown stages in <em>Brassica juncea</em> L.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112609"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"H2O2-generating polyamine oxidases (PAOs) are modulated during sweet pepper ripening: Spermine oxidase (SpmOX) as a case study of post-translational modification regulation","authors":"María A. Muñoz-Vargas,&nbsp;Jorge Taboada,&nbsp;José M. Palma,&nbsp;Francisco J. Corpas","doi":"10.1016/j.plantsci.2025.112606","DOIUrl":"10.1016/j.plantsci.2025.112606","url":null,"abstract":"<div><div>Polyamine oxidases (PAOs) are flavin-containing enzymes involved in the catabolism of polyamines through the oxidative deamination of spermine (Spm) and spermidine (Spd). Transcriptome analysis of pepper (<em>Capsicum annuum</em>) fruit revealed six <em>PAO</em> genes (<em>CaPAO1</em> to Ca<em>P</em>AO6) expressed during ripening. Time-course expression profiling across three developmental stages, green immature (G), breaking point (BP), and red ripe (R), showed differential regulation: <em>CaPAO5</em> and <em>CaPAO6</em> were upregulated during ripening, while <em>CaPAO1</em> and <em>CaPAO3</em> were downregulated. <em>CaPAO4</em> expression remained relatively stable. Exposure to exogenous nitric oxide (NO) gas induced upregulation of <em>CaPAO1</em> to <em>CaPAO3</em> and downregulation of <em>CaPAO4</em> and <em>CaPAO6</em>, with <em>CaPAO5</em> unaffected. Non-denaturing PAGE assays identified four PAO isozymes (CaSpmOX and CaSpdOX I–IV), using Spm or Spd as substrates. CaSpmOX IV and CaSpdOX IV exhibited the highest activities, while CaSpmOX III and CaSpdOX III were progressively inhibited during ripening, with CaSpdOX III showing complete inhibition at the red stage. To assess the influence of signaling molecules, <em>in vitro</em> assays were performed using green fruit extracts treated with nitric oxide (NO) donors (GSNO, CysNO), peroxynitrite (SIN-1), hydrogen sulfide (H₂S) donor (NaHS), hydrogen peroxide, and reducing agents (GSH, L-cysteine). CaSpmOX III emerged as the most sensitive isozyme, displaying 85–100 % inhibition under these treatments. This suggests susceptibility to post-translational modifications (PTMs) such as nitration, <em>S</em>-nitrosation, and persulfidation. Overall, these results demonstrate that H₂O₂-producing CaPAOs are tightly regulated at both the gene and activity levels during fruit ripening, and that NO and H₂S contribute to their modulation, integrating them into the broader redox and signaling network of ripening pepper fruit.</div></div>","PeriodicalId":20273,"journal":{"name":"Plant Science","volume":"359 ","pages":"Article 112606"},"PeriodicalIF":4.2,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}