Rhizosphere microbiome of the drought tolerant common bean

Abstract

The drought is considered one of the major problems in agricultural production in the world, since the main world's agricultural regions are affected by water stress, with a negative impact on the economy and society. Genetic breeding of crops for drought tolerance has received much attention in recent years and new research has provided information on the ability of specific soil microorganisms to influence the water stress tolerance in plants. However, in nature, plants interact simultaneously with a myriad of beneficial and pathogenic microorganisms, revealing the need to understand the cumulative effect of these multiple interactions on the plant's ability to overcome abiotic stresses. Recent studies have revealed that the rhizosphere microbiome plays a fundamental role in the functioning of plants, influencing their physiology and development. Although its importance for plant growth is widely known, for the vast majority of microorganisms in the rhizosphere there is still no information. In this context, this project seeks to evaluate the common bean rhizosphere microbiome in order to identify potential microbial groups that help the plant to overcome the water stress. For this purpose, tolerant and drought susceptible common bean cultivars will be grown in greenhouse experiments under normal conditions and under water stress. The evaluation of the community will be done through DNA sequencing of the communities of bacteria, archaea, fungi, and protists, as well as the functional profile through metagenomics. The microbiome data will be integrated with the physicochemical properties of the soil, and data from the physiology and genetics of the plants, aiming at understanding the genetic control of the host plant in the assembly of the rhizosphere microbiome during water stress. The results will contribute significantly to the understanding of plant-microorganism interactions and their role in helping the plant to tolerate water stress, also aiming to identify microbial groups and functions with potential biotechnological use. Considering the importance of soil microorganisms in the biogeochemical cycles, as well in health promotion and plant growth, the approach of a study focused on microbial ecology is urgently needed for the development of new methods that support agricultural productivity. For the development of the research project, the infrastructure available at CENA-USP will be used, as well the implementation of modern analytical, computational and molecular methods. Drought tolerance in common bean has been the subject of studies in the 'Agroindustrial and Food Productivity Division' at CENA-USP in the last years, where the research has being focused on the physiological and genetic response of the plant. However, this proposal tends to bring an unprecedented approach to the Center, adding the study of the microbiome in association with the genetic and physiological aspects of the plant, establishing a new line of research in 'plant-associated microbiomes'. The development of this proposal will integrate three different laboratories, expanding the analytical capacity of the Division and promoting scientific knowledge in the interface of plant-microbe interaction. The project was structured in order to stimulate cooperation and exchange of experiences among research teams that use different but complementary scientific approaches and methodologies in the environmental and agricultural context. With this project, we hope to obtain data and information that will increase our knowledge about the role of the rhizosphere microbiome in mitigating the effects of drought in plants, providing subsidies for more sustainable use of the ecosystem. (AU)