Rhizobacterial ACC deaminase in plant growth and stress amelioration

Abstract

When plants are continuously exposed to a wide range of environmental stresses, their germination, vigor, growth, and productivity are affected. It has been observed that whenever plants are exposed to stress conditions, stress ethylene is accumulated in the plant tissues, and cause senescence and growth retardation. To overcome these ill effects, intensive breeding programs have focused, over the last several decades, on bringing out resistant crop species with enhanced productivity under suboptimal environmental conditions. However, conventional breeding programs have had concerns over the time taken for the development of resistant varieties and the possible break down of resistance at any time after release. Thus, it is necessary to find long term alternative technology in the agricultural system to ameliorate the ill effects of stress factors. Fortunately, some of the plant growth promoting rhizobacteria that reside near the root region of the plant species possess the mechanism for lowering the accumulation of stress ethylene in stressed plants. The bacterium has an enzyme 1-Aminocyclopropane-1-carboxylate deaminase that intermediates with ethylene synthesis pathway and regulates ethylene accumulation, which, in turn, reduces the damage caused by environmental stresses. Thus, a comprehensive review of the role of rhizobacterial ACC deaminase in plant growth and stress resistance in various agricultural settings is necessary to study its impact on sustainable agriculture and the results of earlier studies will facilitate further research on the aspects of ACC deaminase mediated stress amelioration.