Abstract

Salt stress represents one of the most problematic abiotic stress affecting plants worldwide. In saline soils, plants try to counteract the consequences of salt stress by physiological changes, leading to the decreasing of both osmotic and oxidative stresses. Plant growth-promoting bacteria (PGPB) can ameliorate plant stress response by several mechanisms. In this work, we focused on the effects of halotolerant strain Arthrobacter globiformis on salt stress response in Brassica napus. The strain was inoculated on seeds of three rapeseed cultivars with different levels of salt tolerance; seed germination and following first phases of development were examined in plants exposed to high salinity. Compared to not inoculated plants under the same saline conditions, the inoculated showed a better stress response in the seedling phase. Moreover, a significant increase in phenolic compounds, as well as in Phenylalanine ammonia-lyase (PAL) and Superoxide dismutase (SOD) enzymatic activities were observed in inoculated plants; the concentration of the osmolyte proline was also significantly enhanced in comparison to the not inoculated ones. A. globiformis was proved to be a promising PGPB strain and it can be a tool to counteract salt stress in quite an effective manner, even at high saline conditions.

摘要

盐胁迫是影响全球植物的最成问题的非生物胁迫之一。在盐渍土壤中，植物试图通过生理变化来抵消盐胁迫的后果，从而降低渗透胁迫和氧化胁迫。植物生长促进细菌 (PGPB) 可以通过多种机制改善植物的应激反应。在这项工作中，我们重点研究了耐盐菌株球状节杆菌对欧洲油菜盐胁迫反应的影响。. 将该菌株接种于耐盐程度不同的3个油菜品种的种子上；在暴露于高盐度的植物中检查种子萌发和随后的第一阶段发育。与相同盐度条件下未接种的植物相比，接种的植物在幼苗期表现出更好的胁迫响应。此外，在接种植物中观察到酚类化合物以及苯丙氨酸解氨酶 (PAL) 和超氧化物歧化酶 (SOD) 酶活性显着增加；与未接种的相比，渗透剂脯氨酸的浓度也显着提高。A. globiformis被证明是一种很有前途的 PGPB 菌株，即使在高盐度条件下，它也可以成为一种以非常有效的方式抵消盐胁迫的工具。