Light signaling-dependent cuticle formation in tomato fruits

• Grant number: 21/10498-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2022
• End date: October 31, 2024
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Luciano Freschi
• Grantee: Letícia Danielle Longuini Gomes
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The cuticle contributes in multiple ways to the adaptation of plants under different environmental conditions. In fleshy fruits, such as tomatoes (Solanum lycopersicum), the control of cuticle formation has a high relevance for both fruit physiology and agronomic/commercial aspects. Recently, studies carried out on A. thaliana plants and maize leaves have demonstrated a possible activation of genes involved in cuticle biosynthesis in response to phytochrome(PHY)-dependent light stimuli perception, whit consequences for the cuticular wax biosynthesis and deposition in vegetative tissues. However, role of PHYs in controlling cuticle formation in fleshy fruits remains elusive. Therefore, this project aims to characterize the possible role played by PHYs and PHY-related signaling elements (e.g. PIFs) in controlling fruit cuticle biosynthesis and its consequences for the agronomic/commercial aspects in tomato fruits. To investigate these interactions, we propose to: (1) evaluate the impacts of light spectra composition (simulated shade versus unshaded conditions) on the fruit cuticle formation in wildtype plants, (2) characterize the involvement of the PHYs-PIFs module on cuticle formation via genetic approaches (mutants and transgenics), (3) identify cuticle formation-related genes regulated by the PHYs-PIFs signaling module through gene expression profiling as well as transactivation and ChIP-qPCR assays. The project will utilize tomato mutants and transgenic lines already available in our laboratory, whose ripe fruits will be used for a comprehensive analysis of cuticle composition and structure, post-harvest water loss and resistance to pathogen attack. Moreover, immature green and breaker fruits will be used for assessing the expression profile of key genes related to cuticle formation and deposition. By using these approaches, we expect to generate comprehensive knowledge about the role of PHYs and PIFs signaling on the cuticle formation in fleshy fruits, which may facilitate identifying new biotechnological alternatives to minimize the economic losses caused by losses due to excessive postharvest water loss and rotting during production and transport of these fruits.