关键词: 盐胁迫, 土壤微生物, 根际促生细菌, 丛枝菌根真菌, 内生菌, 合成群落, 植物耐盐性

Abstract:

Soil salinization has seriously hindered the sustainable agricultural production. Remediation of salt affected areas with efficient, low cost and adaptable method is a challenging goal for scientists. Soil microorganisms play important roles in regulating rhizosphere environment of plants, enhancing plant development and productivity. Adaptation of plants to stress driven by soil microbes has been attracted extensive attention. The identification and exploitation of soil microorganisms that interact with plants in alleviating salt stress provides a new strategy for the improvement of saline area, as well as new approaches to discover mechanisms involved in stress tolerance. Knowledge of the underlying physiological mechanisms by which diverse microbes mediate stress tolerance, is critical to the effective use of these microbes to assure sustained agricultural production. This paper reviewed the recent studies about the mechanisms of soil microorganisms mediated in plant salt stress tolerance from the aspects of plant nutrient absorption, osmosis balance, hormone levels and antioxidant function. The beneficial effects and lack of current researches related to soil microorganism in the regulation of plant salt tolerance were evaluated, and the directions of the future research were also proposed. At present, improving nutrient and water uptake efficiency to maintain plant ion homeostasis under salt stress, increasing auxin synthesis and reducing ethylene release to regulate plant hormone levels seem to be promising target processes for soil biota-improved plant salt tolerance. However, limited success has been obtained in application of microorganism to large-scale agricultural production, due to the competition of introduced single microbial strains with native soil microbial communities which resulted in many bacterial strains has little colonization efficiency. The researches related to microbial mediated plant salinity tolerance should break through the single microbial inoculation, further clarify the mechanism of plant-microbial interaction at the community level, and solve the key problems of microbial utilization in agricultural production.

Key words: salt stress, soil microorganisms, plant growth promoting rhizobacteria, arbuscular mycorrhizal fungi, endophytes, synthetic community, plant salt-tolerance