DYNAMICS OF REACTIVE OXYGEN SPECIES AND ANTIOXIDANT IN RED BEET SUBMITTED TO CUTTING AND APPLICATION OF CITRIC ACID

• Grant number: 23/06138-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2023
• End date: May 31, 2024
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Ricardo Alfredo Kluge
• Grantee: Fernanda Tiemi Kito
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Abiotic stress induces cellular defense metabolites in plants. These metabolites are produced in secondary metabolism and are responsible for the antioxidant action and combating cell damage. However, when the plant is under stress, not all products are beneficial and their damage is not always fully controlled. In the case of vegetables such as red beets, which have an efficient antioxidant feedback, due to the presence of betalains and polyphenols, an increase in these compounds is expected after cutting. This action is triggered by stress signaling through an increase in reactive oxygen species (ROS). From this signaling, specific tissue responses can occur, such as ethylene production, synthesis of compounds and action of antioxidant enzymes, increase in respiratory rate and induction of jasmonic acid. Although these responses to ROS are still not well elucidated in the tissues of the swollen hypocotyl of beetroot, the antioxidant response has already been demonstrated in red beets subjected to stress induced by cutting. Furthermore, there is a gap regarding the participation of ethylene in this process since underground tissues are known to be low producers of ethylene. Processing increases the perishability of the vegetable and to maintain its freshness conservation methods are applied, among them additives. There is evidence that the citric acid additive acts in the conservation of red beet tissues and betalains, however, it is not yet fully elucidated whether these results come from a direct antioxidant response or are related to the modulation of responses to oxidative stress. In view of this, the research aims to understand the metabolic responses to abiotic stress of beets after cutting, in association with the application of citric acid and the monitoring of stress signaling and antioxidant feedback in tissues.