Ran Linling, Wu Haoyang, Xia Fei, Xue Yunyin, Wei Wei, Wang Junqiang, Wang Jinglong, Zhao Shanshan, Yan Shuang, Shi Hao, Zheng Shaikun, Zhang Yu, Qiu Xiaoqin
Key Laboratory of Southwest China Wildlife Resource Conservation (Ministry of Education), China West Normal University, Nanchong, China.
State Key Laboratory of Highland Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa, China.
PLoS One. 2025 May 12;20(5):e0323613. doi: 10.1371/journal.pone.0323613. eCollection 2025.
Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that facilitate plant growth and can be used in the restoration of ecosystems. However, PGPR vary in their temperature tolerance, and few studies have investigated the effect of temperature on PGPR-mediated growth promotion or PGPR inoculum colonization. Therefore, we isolated and purified rhizosphere bacteria from the rhizosphere soil of Elymus nutans Griseb (EnG), collected from the Qinghai-Tibet Plateau. Selective culture media were used to assess whether these strains possess plant growth-promoting abilities and to measure the magnitude of their plant growth-promoting ability. Then screen out the strains (S1, S2, S3, S4, and S5) with strong plant growth-promoting ability for identification. To demonstrate the growth-promoting effects of the selected PGPR, we conducted a study. In this study, we simulated three temperature gradients (10°C, 15°C, and 20°C) during the growing season of EnG on the Tibetan Plateau. Furthermore, we established four incubation substrate treatments: T1(addition of PGPR but no addition of NPK fertilizers), T2 (neither PGPR nor NPK fertilizers addition), T3 (addition of PGPR both and NPK fertilizers), and T4 (addition of NPK fertilizers but not PGPR), to explore the effects of PGPR on the growth and nutrient (NPK) utilization efficiency of EnG at different temperatures. The results revealed that compared with those under T2, the plant height (PT) and dry weight under, T1 increased by 51.72% - 70.67% and 24.99-51.25%, respectively. The soluble sugar (SS) and soluble protein (SP) content significantly increased by 59.37% and 369.66%, respctively, at 10 °C (p < 0.05) and by 100.17% and 94.5%, respectively, at 15 °C (p < 0.05). Compared with those under T4, the physiological efficiencies of N (NPE) at 15 °C and 20 °C significantly decreased by 40.43% and 72.11%, respectively, under T3. In summary, these showed that this PGPR (S1, S2, S3, S4, and S5) promoted the growth of EnG on the Tibetan plateau and improved its nutrient utilization efficiency.
植物促生根际细菌（PGPR）是一类有助于植物生长的有益细菌，可用于生态系统恢复。然而，PGPR的耐温性各不相同，很少有研究调查温度对PGPR介导的生长促进作用或PGPR接种物定殖的影响。因此，我们从青藏高原采集的垂穗披碱草（EnG）根际土壤中分离并纯化了根际细菌。使用选择性培养基评估这些菌株是否具有促进植物生长的能力，并测量其促进植物生长能力的大小。然后筛选出具有较强植物生长促进能力的菌株（S1、S2、S3、S4和S5）进行鉴定。为了证明所选PGPR的促生长效果，我们开展了一项研究。在本研究中，我们模拟了青藏高原EnG生长季节的三个温度梯度（10℃、15℃和20℃）。此外，我们设置了四种培养底物处理：T1（添加PGPR但不添加氮磷钾肥料）、T2（既不添加PGPR也不添加氮磷钾肥料）、T3（同时添加PGPR和氮磷钾肥料）和T4（添加氮磷钾肥料但不添加PGPR），以探究PGPR在不同温度下对EnG生长和养分（氮磷钾）利用效率的影响。结果表明，与T2处理相比，T1处理下的株高（PT）和干重分别增加了51.72% - 70.67%和24.99 - 51.25%。在10℃时，可溶性糖（SS）和可溶性蛋白（SP）含量分别显著增加了59.37%和369.66%（p < 0.05），在15℃时分别增加了100.17%和94.5%（p < 0.05）。与T4处理相比，在T3处理下，15℃和20℃时的氮生理效率（NPE）分别显著降低了40.43%和72.11%。综上所述，这些结果表明这种PGPR（S1、S2、S3、S4和S5）促进了青藏高原EnG的生长并提高了其养分利用效率。
