Rangseekaew Pharada, Barros-Rodríguez Adoración, Pathom-Aree Wasu, Manzanera Maximino
Doctor of Philosophy Program in Applied Microbiology (International Program) in Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand.
Biology (Basel). 2022 Jan 26;11(2):191. doi: 10.3390/biology11020191.
Salt stress is a serious agricultural problem threatens plant growth and development resulted in productivity loss and global food security concerns. Salt tolerant plant growth promoting actinobacteria, especially deep-sea actinobacteria are an alternative strategy to mitigate deleterious effects of salt stress. In this study, we aimed to investigate the potential of deep-sea MT1.1 to mitigate salt stress in tomato seedlings and identified genes related to plant growth promotion and salt stress mitigation. MT1.1 exhibited plant growth promoting traits namely indole-3-acetic acid (IAA) and siderophore production and phosphate solubilization under 0, 150, 300, and 450 mM NaCl in vitro. Inoculation of MT1.1 improved tomato seedlings growth in terms of shoot length and dry weight compared with non-inoculated seedlings under 150 mM NaCl. In addition, increased total soluble sugar and total chlorophyll content and decreased hydrogen peroxide content were observed in tomato inoculated with MT1.1. These results suggested that this strain mitigated salt stress in tomatoes via osmoregulation by accumulation of soluble sugars and HO scavenging activity. Genome analysis data supported plant growth promoting and salt stress mitigation potential of MT1.1. Survival and colonization of MT1.1 were observed in roots of inoculated tomato seedlings. Biosafety testing on MT1.1 and in silico analysis of its whole genome sequence revealed no evidence of its pathogenicity. Our results demonstrate the potential of deep-sea MT1.1 to mitigate salt stress in tomato seedlings and as a candidate of eco-friendly bio-inoculants for sustainable agriculture.
盐胁迫是一个严重的农业问题，它威胁着植物的生长和发育，导致生产力损失，并引发全球粮食安全问题。耐盐促植物生长放线菌，尤其是深海放线菌，是减轻盐胁迫有害影响的一种替代策略。在本研究中，我们旨在探究深海MT1.1缓解番茄幼苗盐胁迫的潜力，并鉴定与植物生长促进和盐胁迫缓解相关的基因。MT1.1在体外0、150、300和450 mM NaCl条件下表现出促植物生长特性，即吲哚-3-乙酸（IAA）和铁载体的产生以及磷酸盐溶解。与150 mM NaCl条件下未接种的幼苗相比，接种MT1.1可提高番茄幼苗的茎长和干重。此外，接种MT1.1的番茄中总可溶性糖和总叶绿素含量增加，过氧化氢含量降低。这些结果表明，该菌株通过可溶性糖的积累和清除过氧化氢的活性进行渗透调节，从而缓解了番茄的盐胁迫。基因组分析数据支持MT1.1具有促植物生长和缓解盐胁迫的潜力。在接种的番茄幼苗根部观察到MT1.1的存活和定殖。对MT1.1的生物安全性测试及其全基因组序列的计算机分析均未发现其致病性证据。我们的结果证明了深海MT1.1缓解番茄幼苗盐胁迫的潜力，以及作为可持续农业中生态友好型生物接种剂候选物的潜力。
