Biochemical and genetic mechanisms used by plant growth-promoting bacteria

术语"植物生长促进细菌"描述了与植物（通常与根）有益相关的土壤细菌。这些细菌利用各种机制促进植物生长。然而，为了使植物生长促进细菌在农业，园艺和环境净化中的使用更加有效，可预测和可重复，有必要首先了解控制这些生物体和植物之间关系的基本遗传和生化机制。在这方面，植物生长促进细菌使用的主要机制之一涉及酶1-氨基环丙烷-1-羧酸（ACC）脱氨酶，其裂解化合物ACC，即所有高等植物中植物激素乙烯的直接前体。含有ACC脱氨酶的植物生长促进细菌菌株为广泛的不同植物物种提供显著水平的保护，以免受由各种环境胁迫引起的损害，所述环境胁迫包括植物病原体、洪水、重金属、干旱、极端温度、有机环境污染物的存在和高盐。在这里提出的工作中：植物生长促进细菌和植物如何影响彼此的基因表达的细节将被阐述;一些共生细菌与ACC脱氨酶功能的细节将被研究;并努力了解植物的生长方式仅与植物根部结合的促进细菌在促进植物生长方面不同于定殖在植物内部的那些细菌。

The term "plant growth-promoting bacteria" describes soil bacteria that are involved in a beneficial association with plants (often with the roots). These bacteria use a variety of mechanisms to facilitate plant growth. However, in order to make the use of plant growth-promoting bacteria in agriculture, horticulture and environmental cleanup, more efficacious, predictable and reproducible, it is necessary to first understand the fundamental genetic and biochemical mechanisms that govern the relationship between these organisms and plants. In this regard, one of the major mechanisms used by plant growth-promoting bacteria involves the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase which cleaves the compound ACC, the immediate precursor of the phytohormone ethylene in all higher plants. Plant growth-promoting bacterial strains that contain ACC deaminase provide a wide range of different plant species with a significant level of protection from the damage caused by various environmental stresses including phytopathogens, flooding, heavy metals, drought, temperature extremes, the presence of organic environmental contaminants, and high salt. In the work that is proposed here: the details of how plant growth-promoting bacteria and plants impact one another's gene expression will be elaborated; some of the details of how symbiotic bacteria with ACC deaminase function will be investigated; and efforts will be made to understand how plant growth-promoting bacteria that bind only to a plant's roots differ from those that colonize the interior of the plant in their promotion of plant growth.