Cyanobacteria isolated from extreme environments as biostimulants in plant cultivation in response to climate change

• Grant number: 23/09261-3
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2023
• End date: October 31, 2025
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Marli de Fátima Fiore
• Grantee: Marli de Fátima Fiore
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Annick Wilmotte ; Ernani Pinto Junior ; Francisco Dini Andreote
• Associated scholarship(s): 24/02448-3 - Analysis of the impact of cyanobacteria inoculation on the maize rhizosphere community, BP.TT

Abstract

The effects of global warming influence the productivity of the world's main crops and can trigger shortages of food and other products, causing social and economic damage. Several studies have been carried out to characterize the physiological and morphological changes of crops in response to environmental changes. More recently, the manipulation of the microbial community associated with these cultures highlighted the potential in these relations to provide resistance to biotic and abiotic stresses. The association between host plants and microorganisms, resulting in thousands of years of evolution, made them share an intimate physiological and genetic relationship. Thus, biofertilizers and plant biostimulants (PBs) are being developed from microbial consortia, seeking to generate greater resistance to environmental stresses such as high temperatures and water stress (drought). BPs improve the productivity and quality of crops in general, increasing the availability and absorption of nutrients, and promoting the degradation and solubilization of organic substances in the soil. In this sense, the rhizosphere is an initial reservoir of microbial diversity in the soil. This environment harbours a high species richness, which interacts not only with the host plant in response to its exudates but also with each other, creating a complex communication network. Recent studies have underlined the ability of plant-associated microbiomes to influence traits such as growth, drought tolerance, and disease resistance. Among the beneficial microorganisms for plants, cyanobacteria can fix atmospheric carbon and nitrogen and promote the solubilization of phosphorus and iron. These organisms also produce a variety of biologically active molecules, such as plant hormones (auxins and gibberellins), antimicrobials, and exopolysaccharides (capable of acting in moisture retention). Consequently, they can positively influence plant fitness and increase their tolerance to abiotic stresses. Thus, they are a promising source for the development of new PBs. Despite this potential, this group of organisms is still underexplored, mainly concerning its role in association with microbiomes and crops under climatic stress conditions, such as drought or higher temperatures. Microorganisms from extreme environments naturally have a potential metabolic response to abiotic stress. Thus, the evaluation of cyanobacteria from environments such as Antarctica, desert soils (Desert of Atacama and Brazilian Caatinga), and alkaline lakes of the Pantanal, may reveal this potential response to low temperatures, drought, and high pH, respectively. In this scenario, this project aims to evaluate the biostimulant effect of cyanobacterial extracts on crops of commercial and economic importance, such as wheat and corn, exposed to abiotic stress (drought). The information generated will allow the detection and characterization of molecules with biostimulant potential. In addition, the effect of extremophile cyanobacterial metabolites on the microbial community of the rhizosphere will be evaluated. (AU)