Abstract：
The scarcity of soil nutrient availability under cold conditions of Himalayan regions needs a sustainable approach for better crop yields. The cold-adapted bacteria, Exiguobacterium sibiricum K1, with the potential to produce several plant growth-promoting (PGP) attributes, nitrogen fixation, indole acetic acid production, phosphate and potassium solubilization at 10 °C can provide an opportunity to promote crop yield improvement in an eco-friendly way under cold conditions. The bacterium also exhibited biocontrol activity against two phytopathogens and produced siderophore (53.0 ± 0.5 % psu). The strain\'s PGP properties were investigated using a spinach-based bioassay under controlled conditions. The bacterized seeds showed a notable increase in germination rate (23.2 %), shoot length (65.3 %), root length (56.6 %), leaf area (73.7 %), number of leaflets (65.2 %), and dry matter (65.2 %). Additionally, the leaf analysis indicated elevated chlorophyll pigments, i.e., chlorophyll a (55.5 %), chlorophyll b (42.8 %), carotenoids (35.2 %), percentage radical scavenging activity (47.4 %), and leaf nutrient uptake such as nitrogen (23.4 %), calcium (60.8 %), potassium (62.3 %), and magnesium (28.9 %). Moreover, the whole-genome sequencing and genome mining endorsed various biofertilisation-related genes, including genes for potassium and phosphate solubilization, iron and nitrogen acquisition, carbon dioxide fixation, and biocontrol ability of Exiguobacterium sibiricum K1. Overall, this study highlights the role of Exiguobacterium sibiricum K1 as a potential bioinoculant for improving crop yield under cold environments.
摘要：
喜马拉雅地区寒冷条件下土壤养分利用率的缺乏需要一种可持续的方法来提高作物产量。适应寒冷的细菌，sibiricumK1，具有产生多种植物生长促进（PGP）属性的潜力，固氮,吲哚乙酸生产，磷酸盐和钾在10°C下的溶解可以提供在寒冷条件下以环保方式促进作物产量提高的机会。该细菌还表现出针对两种植物病原体的生物防治活性，并产生铁载体（53.0±0.5％psu）。在受控条件下使用基于菠菜的生物测定法研究了菌株的PGP特性。菌种发芽率显著提高(23.2%),枝条长度（65.3%），根长（56.6%），叶面积（73.7%），小叶数目(65.2%),和干物质(65.2%)。此外,叶片分析表明叶绿素色素升高，即，叶绿素a(55.5%)，叶绿素b（42.8％），类胡萝卜素（35.2%），自由基清除活性百分比(47.4%)，和叶片养分吸收，如氮(23.4%)，钙（60.8%），钾（62.3%），和镁（28.9%）。此外，全基因组测序和基因组挖掘认可了各种与生物受精相关的基因，包括钾和磷酸盐溶解的基因，铁和氮的获取，二氧化碳固定，sibiricumexiguobacteriumK1的生物防治能力。总的来说,这项研究强调了sibiricumK1作为在寒冷环境下提高作物产量的潜在生物接种剂的作用。
