Biodiversity and Biotechnological Applications of Microorganisms Associated with Tropical Plants

Abstract

According to the World Trade Organization, the largest agrarian producers in the world are in the tropics. Moreover, the appreciated global resources of biological diversity also occur in tropical areas, such as the Amazon, which is considered one of the chief rain forests and plays a significant role in protection and discovery of novel microbial, plant, and animal species. However, data from tropical regions are scarce. Little is known about the great biodiversity of microorganisms and the application of these resources to improve tropical agriculture. Tropical agriculture presents more problems of greater complexity than agriculture in temperate climates. One approach for solving some agricultural problems in the tropics is sustainable use of microorganisms. Efficient microbes have shown potential in the agricultural field for use in plant development and growth promotion, mostly by delivering valuable compounds to their host plants. Microbial plant growth promoters may improve crop development and growth in numerous biological ways, such as production of secondary metabolites (for example, plant development hormones, including auxins), production of siderophores, phosphate solubilization, and nitrogen fixation. Microorganisms have also received considerable attention because of their potential for use as agents for biological control of various plant fungal pathogens and bacterial diseases. There are numerous processes associated with plant–pathogen hostility. The competition for space and nutrients in the host plant, in the rhizospheric region, and in the soil can be fierce, as can the production of antimicrobial complexes that directly affect plant pathogens. These mainly include lytic enzymes, antibiotics, volatile organic compounds, and other compounds. This review discusses studies on the microorganism diversity that is present in well-established tropical crops, with examples of successful use of microorganisms in solving tropical problems, with the aim being to achieve more sustainable agriculture.