Resposta fisiológica, bioquímica, agronômica e molecular em amendoim submetido a déficit hídrico

Abstract

Climate changes are affecting the productivity of various crops; among these, the peanut (Arachis hypogaea L.) stands out for its great socio-economic value in tropical and sub-tropical regions to be the fifth most grown oilseed in the world. Water stress is one of the abiotic factors that affect productivity. Although the ecophysiological responses of this species are studied, little is known about the molecular events and their metabolic relationships. This study initially examined the physiological, biochemistry and agronomy response, using the method of canonical variables (VCA) and UPGMA in peanut genotypes subjected to water deficit, contributing to identify tolerant genotypes to drought. Physiological changes and activity of enzymes SOD, CAT and APX were measured in the vegetative stage eight peanut genotypes subjected to six days of total water suspension. From which waterings were re-established and analyzed the agronomic damage of stress. It was found that UPGMA method was more contributory to separate genotypes, especially the CNPA 166 AM early lineage, as the most promising for improvement work. Among the trailing lines to BR1xLViPE-06 (B) showed moderate behavior when subjected to water deficit. At the proteomic level, peptides differentially expressed by 1DE and 2DE, involved in several metabolic routes such as photosynthesis, energy metabolism, antioxidative defense and involved in the response to the water deficit present in different cell compartments were identified. Through the sequencing by MS of the peptides by 1DE the peptides ATP synthase, peroxidase, taraxerol synthase and clathrin involved in the response to the damage suffered in the sensitive genotype LViPE-06 and peptidyl-prolyl-cis trans isomerase, beta-1,3-galactosyltransferase , Phosphatase, cytochrome p450 involved in increased tolerance to drought in Senegal-55437. The tolerant genotype Senegal-55437 was chosen for identification of differentially expressed proteins related to drought tolerance through 2DE. A total of 52 differentially expressed proteins were found, of which 32 were identified in treatment with water stress and six were directly involved in drought tolerance routes. Proteins were involved in redox homeostasis, photosynthesis, beta-oxidation and osmoprotection. Seven proteins were found, all involved in several biotic and abiotic processes, including drought tolerance: kinesin, enoyl-CoA hydratase, photosystem I subunit, AP2 / ERF transcription factor, helicase and defensin-like protein. Pioneering studies for these peanut genotypes contributed to the knowledge and evaluation of the adaptive responses that led to metabolic changes in the identification of promising genotypes. At the same time, it opens perspectives for the validation of new markers that can be used in peanut breeding populations aiming at drought tolerance and maintenance of peanut productivity contributing to food stability in the face of climate change and meeting global demands.