盐胁迫下植物根际促生菌对垂穗披碱草生长及生理生化的影响

Effects of plant growth-promoting rhizobacteria ongrowth,physiological,and biochemical responses tosalt-stressed Elymus nutans

摘要:

【目的】 探究植物根际促生菌对垂穗披碱草在盐渍化土壤中生长的影响。【方法】 以课题组前期分离的4 株植物根际促生菌（PGPR）为试验材料，设置不同盐浓度处理，采用沙培法种植垂穗披碱草（Elymus nutans），将4 株植物根际促生菌[（TznFn7、MYnI4、MYP（m）Jn8 和TznG2）]接种剂接种在种植垂穗披碱草的河沙中，测定不同菌株处理和不同盐浓度下垂穗披碱草生长指标和生理特性，研究垂穗披碱草在菌株接种剂处理下的耐盐性。【结果】 在150 mmol/L 盐浓度下，与CK 相比各接种处理的CAT 活性提高2. 08%~7. 35%，接种菌株TznFn7、TznG2 处理下与CK 相比POD 活性提高了27. 24%、13. 30%，各接种处理下SOD 活性提高5. 18%~24. 03%，与CK 相比各接种处理的MDA 含量降低25. 87%~47. 53%。【结论】 在盐胁迫下，接种不同PGPR 菌剂不仅促进垂穗披碱草生长，同时有效提高了植物CAT、POD 和SOD 抗氧化酶活性，降低了植物细胞MDA 含量。本研究选用的PGPR菌株改善了盐胁迫下植物生长，减轻了植物细胞损伤，提高了植物耐盐性，为盐渍化土壤的利用提供了一定的理论和实践基础。

Abstract:

【Objective】 This study investigated the effects of plant growth ‐ promoting rhizobacteria（PGPR） onthe growth of Elymus nutanssalinized soil. 【Method】 Four plant PGPR strains isolated by our research group（TznFn7，MYnI4，MYP（m）Jn8 and TznG2） were tested under varying salt concentrations. E. nutanswas cultivatedin a sand culture system，andthe growth indices and physiological characteristics were assessed under different straintreatments and saltlevels. The study focused on salt tolerance of E. nutans following PGPR innoculation.【Result】Results demonstrated that at a salt concentration of 150 mmol/L，catalase （CAT） activity increased by 2. 08% to7. 35%，while peroxidase（POD） activity rose by 27. 24% and 13. 30% with TznFn7 and TznG2 inoculations，comparedto control（CK）. Superoxide dismutase （SOD） activity increased between 5. 18% and 24. 03% across all innoculatedstrains，and malondialdehyde（ MDA） content decreased from 25. 87% to 47. 53%compared to CK. Inoculationwith different PGPR strains not only promoted the growth of E. nutans under salt stress but also enhanced the activitiesof CAT，POD and SOD，while reducing MDA content in plant cells. This alleviated the cellular damage andimproved the plantsresilience to saline conditions.【Conclusion】 The PGPR strains selected in this study significantlyenhanced plant growth and salt tolerance，providing a theoretical and practical basis for the utilization of saline soils.