Ethylene synthesis and perception during post harvest ripening of tomato fruit that does not accumulate carotenoids

• Grant number: 19/25682-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2020
• End date: January 31, 2021
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Ricardo Alfredo Kluge
• Grantee: Laura Claudino Maziero
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The color promoted by carotenoids is extremely important for maintaining the visual quality of tomato fruit, as well as for determining aroma, taste and nutritional properties. The carotenoid biosynthesis pathway begins with the formation of phytoene by the enzyme phytoene syntheses (PSY), which is the most limiting point of the pathway. Transcriptional control of genes involved in carotenoid synthesis is the main mechanism that regulates the accumulation of these pigments. In tomato, a climacteric fruit, PSY1 expression is mainly controlled by ethylene, as well as transcription factors considered master ripening regulators, such as Ripening Inhibitor (RIN). Although this regulation is well known recently, our research group has observed the occurrence of new pleiotropic effects in fruit of the mutant yellow flesh, characterized by the loss of PSY1 enzyme function. Despite the absence of carotenoids, fruits have high ethylene production, anticipation of climatic peak and accelerated ripening. This fact is intriguing, since there is no direct link between PSY1 and ethylene biosynthesis pathway. Considering the importance of carotenoids and ethylene for fruit quality, we decided to investigate the physiological mechanism by which PSY1 modification affected ethylene production. For this, two hypotheses will be investigated in order to understand if the ethylene synthesis pathway was affected, or if there were changes in the perception of the hormone. This proposal, besides being relevant as a basic research, may generate information of immediate applicability for post harvest fruit, a topic of great economic and strategic importance for food science. (AU)