Microbial Genes, Enzymes, and Metabolites: To Improve Rhizosphere and Plant Health Management

Abstract

In today’s world, there are other important problems, such as climate change and environmental problems and the loss of genetic resources, in addition to the issue of human societies supplying food and creating more food. One of the reasons being the improper use of chemical products in agriculture (such as pesticides and chemical fertilizers, etc.). In recent decades, the growing population of the world and the growing market for food have led to a serious and imminent change from conventional agriculture to advanced agriculture in the agricultural and food sciences and to the use of modern genetic technologies in the production of crops and livestock. The application of the techniques of genetic evolution and molecular genetics in the use of microorganisms and microbial genes to improve the amount and efficiency of goods, on the one hand, and, on the other hand, to minimize costs and processing time, has made the use of these techniques very useful in the different branches of agriculture.  So far, microorganisms have been used in different sectors of agriculture as follows; reducing the toxicity of antibiotics and herbicides (beta-lactam gene), production of fungicides and biocides (chitinase gene), resistance to pathogenic bacteria (WRKY gene family), resistance to citrus bacterial canker (pthA gene), dissolution of soil phosphorus (gabY, Mps, pKKY, pKG3791 and OlpA-Cm genes), tolerance to abiotic stresses (Flavdex gene (Fld), PR5 gene family), coexistence with plants in water and mineral production (mycorrhizal fungus), and editing the plant genome (CRISPR/Cas9 gene).  Various genes have also been used in the removal of soils contaminated with heavy metals and herbicides (atzA, atzB, atzC, atzD, atzE and atzF, BPDO, CotA, and merA genes). Production of sugar biopolymers (Asr gene), production of biofilms, production of dietary supplements for oil enrichment (fatty acyl-ACP thioesterase gene), development of immunity against gas spoilage (alfa-Toxin gene), bioethanol synthesis (Cel6B gene), Baker’s yeast engineered to promote the bakery industry, and engineered yeasts for the production of engineering and industrial alcohol that have also been controlled by other genes. We also attempted to review in this chapter the form and manner in which microbial genes are used directly and indirectly to improve the quantity and efficiency of agricultural products.