{"title":"Preinoculation with Bradyrhizobium japonicum enhances the salt tolerance of Glycine max seedlings by regulating polyamine metabolism in roots","authors":"","doi":"10.1016/j.plaphy.2024.109196","DOIUrl":null,"url":null,"abstract":"<div><div>Rhizobia are common symbiotic microorganisms in the root system of leguminous plants that can usually provide nitrogen to the host through nitrogen fixation. Studies have shown that rhizobium-preinoculated soybean plants usually exhibit improved salt tolerance, but the underlying mechanism is not fully understood. In this paper, transcriptome sequencing (RNA-seq) revealed that preinoculation with rhizobia affected polyamine (PA) metabolism in soybean roots. The assay of PA contents showed that preinoculation with rhizobia significantly increased the putrescine (Put) content in roots and leaves during short-term salt treatment (0–5 d). Long-term salt treatment (5–7 d) resulted in a high Put content and significantly increased Spm and Spd contents, resulting in a rapid increase in the Put/(Spd + Spm) ratio (0–5 d) and subsequent decrease. Moreover, rhizobium preinoculation of soybean plants resulted in increased contents of conjugated and bound PAs under salt stress. Further transcriptome sequencing, PA contents, PA synthase expression and activity analysis revealed that <em>GmADC</em> may be a key gene related to salt tolerance in rhizobium-preinoculated soybean plants, and the <em>GmADC</em>-overexpressing soybean hairy-root composite plants exhibited less ROS damage, lower Cl<sup>−</sup>/NO<sub>3</sub><sup>−</sup> ratios and Na<sup>+</sup>/K<sup>+</sup> ratios, and stabilized ion homeostasis. Taken together, preinoculation with rhizobia increased the expression level and enzyme activity of arginine decarboxylase (ADC) in soybean roots, increased the content of Put in roots and leaves, and increased the content of conjugated and bound PAs in soybean plants, thereby alleviating the oxidative and ionic injuries of soybean plants and enhancing the salt tolerance.</div></div>","PeriodicalId":20234,"journal":{"name":"Plant Physiology and Biochemistry","volume":null,"pages":null},"PeriodicalIF":6.1000,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Physiology and Biochemistry","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0981942824008647","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Rhizobia are common symbiotic microorganisms in the root system of leguminous plants that can usually provide nitrogen to the host through nitrogen fixation. Studies have shown that rhizobium-preinoculated soybean plants usually exhibit improved salt tolerance, but the underlying mechanism is not fully understood. In this paper, transcriptome sequencing (RNA-seq) revealed that preinoculation with rhizobia affected polyamine (PA) metabolism in soybean roots. The assay of PA contents showed that preinoculation with rhizobia significantly increased the putrescine (Put) content in roots and leaves during short-term salt treatment (0–5 d). Long-term salt treatment (5–7 d) resulted in a high Put content and significantly increased Spm and Spd contents, resulting in a rapid increase in the Put/(Spd + Spm) ratio (0–5 d) and subsequent decrease. Moreover, rhizobium preinoculation of soybean plants resulted in increased contents of conjugated and bound PAs under salt stress. Further transcriptome sequencing, PA contents, PA synthase expression and activity analysis revealed that GmADC may be a key gene related to salt tolerance in rhizobium-preinoculated soybean plants, and the GmADC-overexpressing soybean hairy-root composite plants exhibited less ROS damage, lower Cl−/NO3− ratios and Na+/K+ ratios, and stabilized ion homeostasis. Taken together, preinoculation with rhizobia increased the expression level and enzyme activity of arginine decarboxylase (ADC) in soybean roots, increased the content of Put in roots and leaves, and increased the content of conjugated and bound PAs in soybean plants, thereby alleviating the oxidative and ionic injuries of soybean plants and enhancing the salt tolerance.
根瘤菌是豆科植物根系中常见的共生微生物,通常可通过固氮作用为宿主提供氮素。研究表明,预接种根瘤菌的大豆植株通常表现出更强的耐盐性,但其潜在机制尚未完全明了。本文通过转录组测序(RNA-seq)发现,根瘤菌预接种会影响大豆根部的多胺(PA)代谢。PA 含量的检测表明,在短期盐处理(0-5 d)期间,根瘤菌的预接种会显著增加根和叶中的腐胺(Put)含量。长期盐处理(5-7 d)导致 Put 含量较高,Spm 和 Spd 含量明显增加,导致 Put/(Spd + Spm)比值(0-5 d)迅速上升,随后下降。此外,在盐胁迫下,大豆植株接种根瘤菌后,共轭和结合 PA 的含量增加。进一步的转录组测序、PA含量、PA合成酶的表达和活性分析表明,GmADC可能是根瘤菌预接种大豆植株耐盐的关键基因,GmADC过表达的大豆毛根复合植株表现出较少的ROS损伤、较低的Cl-/NO3-比率和Na+/K+比率以及稳定的离子平衡。综上所述,根瘤菌的预接种提高了大豆根系中精氨酸脱羧酶(ADC)的表达水平和酶活性,增加了大豆根系和叶片中 Put 的含量,增加了大豆植株中共轭 PA 和结合 PA 的含量,从而减轻了大豆植株的氧化损伤和离子损伤,增强了耐盐性。
期刊介绍:
Plant Physiology and Biochemistry publishes original theoretical, experimental and technical contributions in the various fields of plant physiology (biochemistry, physiology, structure, genetics, plant-microbe interactions, etc.) at diverse levels of integration (molecular, subcellular, cellular, organ, whole plant, environmental). Opinions expressed in the journal are the sole responsibility of the authors and publication does not imply the editors'' agreement.
Manuscripts describing molecular-genetic and/or gene expression data that are not integrated with biochemical analysis and/or actual measurements of plant physiological processes are not suitable for PPB. Also "Omics" studies (transcriptomics, proteomics, metabolomics, etc.) reporting descriptive analysis without an element of functional validation assays, will not be considered. Similarly, applied agronomic or phytochemical studies that generate no new, fundamental insights in plant physiological and/or biochemical processes are not suitable for publication in PPB.
Plant Physiology and Biochemistry publishes several types of articles: Reviews, Papers and Short Papers. Articles for Reviews are either invited by the editor or proposed by the authors for the editor''s prior agreement. Reviews should not exceed 40 typewritten pages and Short Papers no more than approximately 8 typewritten pages. The fundamental character of Plant Physiology and Biochemistry remains that of a journal for original results.