State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, 810016, China.
College of Agriculture and Animal Husbandry, Qinghai University, Xining, 810016, China.
Antonie Van Leeuwenhoek. 2024 Jan 8;117(1):16. doi: 10.1007/s10482-023-01917-x.
The unique eco-environment of the Qinghai-Tibet Plateau breeds abundant microbial resources. In this research, Bacillus amyloliquefaciens GL18, isolated from the rhizosphere of Kobresia myosuroides from an alpine meadow, and the antagonistic activity, bacteriostatic hydrolase activity, and low temperature, salt, and drought resistance of it were determined and analysed. The seedlings of Avena sativa were root-irrigated using bacteria suspensions (cell concentration 1 × 10 cfu/mL) of GL18, and the growth-promoting effect of GL18 on it was determined under cold, salt and drought stress, respectively. The whole genome of GL18 was sequenced, and its functional genes were analysed. GL18 presented significant antagonistic activity to Fusarium graminearum, Fusarium acuminatum, Fusarium oxysporum and Aspergillus niger (inhibition zone diameter > 17 mm). Transparent zones formed on four hydrolase detection media, indicating that GL18 secreted cellulase, protease, pectinase and β-1,3-glucanase. GL18 tolerated conditions of 10 °C, 11% NaCl and 15% PEG-6000, presenting cold, salt and drought resistance. GL18 improved the cold, salt and drought tolerance of A. sativa and it showed significant growth effects under different stress. The total length of the GL18 genome was 3,915,550 bp, and the number of coding DNA sequence was 3726. Compared with the clusters of orthologous groups of proteins, gene ontology and kyoto encyclopedia of genes and genomes databases, 3088, 2869 and 2357 functional genes were annotated, respectively. GL18 contained gene clusters related to antibacterial substances, functional genes related to the synthesis of plant growth-promoting substances, and encoding genes related to stress resistance. This study identified an excellent Bacillus strain and provided a theoretical basis for improving stress resistance and promoting the growth of herbages under abiotic stress.
青藏高原独特的生态环境孕育了丰富的微生物资源。本研究从高寒草甸川滇嵩草根际分离得到解淀粉芽孢杆菌 GL18，对其拮抗活性、抑菌水解酶活性、耐低温、耐盐、耐旱性进行了测定和分析。采用浓度为 1×10~cfu/mL 的 GL18 菌悬液对燕麦幼苗进行灌根处理，研究 GL18 在低温、盐和干旱胁迫下对其生长的促进作用。对 GL18 进行全基因组测序，并对其功能基因进行分析。GL18 对禾谷镰刀菌、串珠镰刀菌、尖孢镰刀菌和黑曲霉（抑菌圈直径＞17mm）具有显著的拮抗活性。在 4 种水解酶检测培养基上形成透明圈，表明 GL18 分泌纤维素酶、蛋白酶、果胶酶和β-1,3-葡聚糖酶。GL18 能耐受 10°C、11%NaCl 和 15%PEG-6000，具有耐低温、耐盐和耐旱性。GL18 提高了燕麦的耐冷、耐盐和耐旱性，在不同胁迫下表现出显著的生长效应。GL18 基因组全长 3915550bp，编码 DNA 序列数为 3726 个。与蛋白质直系同源簇、基因本体和京都基因与基因组百科全书数据库相比，分别注释了 3088、2869 和 2357 个功能基因。GL18 含有抗菌物质相关基因簇、植物生长促进物质合成相关功能基因和编码抗逆相关基因。本研究鉴定了一株优良芽孢杆菌，为提高牧草在非生物胁迫下的抗逆性和促进生长提供了理论依据。
