Srivastava Alok Kumar, Srivastava Ruchi, Sharma Anjney, Bharati Akhilendra Pratap, Yadav Jagriti, Singh Alok Kumar, Tiwari Praveen Kumar, Srivatava Anchal Kumar, Chakdar Hillol, Kashyap Prem Lal, Saxena Anil Kumar
Indian Council of Agricultural Research-National Bureau of Agriculturally Important Microorganisms, Mau, India.
Department of Life Science and Biotechnology, Chhatrapati Shahu Ji Maharaj University, Kanpur, India.
Front Microbiol. 2022 Jun 30;13:909276. doi: 10.3389/fmicb.2022.909276. eCollection 2022.
Soil salinity is one of the major global issues affecting soil quality and agricultural productivity. The plant growth-promoting halophilic bacteria that can thrive in regions of high salt (NaCl) concentration have the ability to promote the growth of plants in salty environments. In this study, attempts have been made to understand the salinity adaptation of plant growth-promoting moderately halophilic bacteria ANJ207 at the genetic level through transcriptome analysis. In order to identify the stress-responsive genes, the transcriptome sequencing of ANJ207 under different salt concentrations was carried out. Among the 8,936 transcripts obtained, 93 were upregulated while 1,149 were downregulated when the NaCl concentration was increased from 5 to 10%. At 10% NaCl concentration, genes coding for lactate dehydrogenase, catalase, and OsmC-like protein were upregulated. On the other hand, when salinity was increased from 10 to 25%, 1,954 genes were upregulated, while 1,287 were downregulated. At 25% NaCl, genes coding for PNPase, potassium transporter, aconitase, excinuclease subunit ABC, and transposase were found to be upregulated. The quantitative real-time PCR analysis showed an increase in the transcript of genes related to the biosynthesis of glycine betaine coline genes (gbcA, gbcB, and L-pro) and in the transcript of genes related to the uptake of glycine betaine (OpuAC, OpuAA, and OpuAB). The transcription of the genes involved in the biosynthesis of L-hydroxyproline (proD and proS) and one stress response proteolysis gene for periplasmic membrane stress sensing (serP) were also found to be increased. The presence of genes for various compatible solutes and their increase in expression at the high salt concentration indicated that a coordinated contribution by various compatible solutes might be responsible for salinity adaptation in ANJ207. The investigation provides new insights into the functional roles of various genes involved in salt stress tolerance and oxidative stress tolerance produced by high salt concentration in ANJ207 and further support the notion regarding the utilization of bacterium and their gene(s) in ameliorating salinity problem in agriculture.
土壤盐渍化是影响土壤质量和农业生产力的主要全球性问题之一。能够在高盐（氯化钠）浓度区域生长的促进植物生长的嗜盐细菌具有在盐渍环境中促进植物生长的能力。在本研究中，已尝试通过转录组分析在基因水平上了解促进植物生长的中度嗜盐细菌ANJ207的盐度适应性。为了鉴定应激反应基因，对ANJ207在不同盐浓度下进行了转录组测序。在获得的8936个转录本中，当氯化钠浓度从5%增加到10%时，93个转录本上调，1149个转录本下调。在10%氯化钠浓度下，编码乳酸脱氢酶、过氧化氢酶和类OsmC蛋白的基因上调。另一方面，当盐度从10%增加到25%时，1954个基因上调，1287个基因下调。在25%氯化钠浓度下，发现编码多核苷酸磷酸化酶、钾转运蛋白、乌头酸酶、核酸外切酶亚基ABC和转座酶的基因上调。定量实时PCR分析表明，与甘氨酸甜菜碱胆碱基因（gbcA、gbcB和L-pro）生物合成相关的基因转录本以及与甘氨酸甜菜碱摄取相关的基因（OpuAC、OpuAA和OpuAB）转录本增加。还发现参与L-羟基脯氨酸生物合成的基因（proD和proS）以及一个用于周质膜应激感应的应激反应蛋白水解基因（serP）的转录增加。各种相容性溶质基因的存在及其在高盐浓度下的表达增加表明，各种相容性溶质的协同作用可能是ANJ207适应盐度的原因。该研究为ANJ207中参与盐胁迫耐受性和高盐浓度产生的氧化应激耐受性的各种基因的功能作用提供了新见解，并进一步支持了关于利用细菌及其基因改善农业盐度问题的观点。
