Study of ethylene action and methyl jasmonate influence on pepper ripening by metabolomic and differential proteomic

• Grant number: 15/06336-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2015
• End date: August 29, 2019
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Eduardo Purgatto
• Grantee: Isabel Louro Massaretto
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 17/12311-1 - Salinity stress impact on the tomato quality: the role of plastids and jasmonate., BE.EP.PD

Abstract

Nutritional and sensory characteristics of each fruit are developed during ripening due to the biosynthesis of certain metabolites as a result of enzymes activities in different metabolic pathways. Ethylene is considered the critical regulator in the maturation process of climateric fruits, whereas in non-climacteric its function is not evident. Furthermore, other phytohormones such as jasmonates, auxin and abscisic acid are also involved in this process. This project aims to study the regulation of ripening in pepper, a non-climacteric fruit, which belongs to the same family as the well-characterized climacteric tomato (Solanaceae). Pepper can be a potential model for non-climacteric fruits ripening studies, due to its great diversity of species and varieties, the plant short life cycle and because its genome was recently sequenced. Capsicum baccatum ("dedo-de-moça") and Capsicum chinense ("habanero") fruits will be divided in groups and treated with: ethylene, methyl jasmonate and 1-methylcyclopropene, and compared to an untreated control group. During ripening, the fruits will be analyzed for respiration, ethylene production, color and profile of volatile compounds at the starting point and after four periods of time. At starting point and one of the selected periods, treated and control groups will be analyzed as follows: targeted metabolomics, to evaluate the production of secondary metabolites related to pepper quality (carotenoids, capsaicionoids and volatile aroma compounds); non-targeted metabolomics to assess qualitative and quantitative changes in the primary metabolism, whose compounds are precursors of secondary metabolites; and proteomics to verify changes in protein expression in various biochemical pathways, especially those relating to the biosynthesis of secondary metabolic compounds. The idea is to highlight potential points of hormones regulation through metabolic pathways related to the biosynthesis of primary and secondary metabolites and elucidate whether these processes are conserved between the species. Pepper breeding programs and post-harvest technology applications can be developed from this knowledge, which also can be a base to understand the relation between biochemical regulation and quality-related characteristics in non-climacteric fruits. (AU)