Abstract
Hormones play an important role in fruit ripening and in response to biotic stress. Nevertheless, analyses of hormonal profiling during plant development and defense are scarce. In this work, changes in hormonal metabolism in grapevine (Vitis vinifera) were compared between a susceptible (Trincadeira) and a tolerant (Syrah) variety during grape ripening and upon infection with Botrytis cinerea. Infection of grapes with the necrotrophic pathogen Botrytis cinerea leads to significant economic losses worldwide.Peppercorn-sized fruits were infected in the field and mock-treated and infected berries were collected at green, veraison and harvest stages for hormone analysis and targeted qPCR analysis of genes involved in hormonal metabolism and signaling. Results indicate a substantial reprogramming of hormonal metabolism during grape ripening and in response to fungal attack. Syrah and Trincadeira presented differences in the metabolism of abscisic acid (ABA), indole-3-acetic acid (IAA) and jasmonates during grape ripening that may be connected to fruit quality. On the other hand, high basal levels of salicylic acid (SA), jasmonates and IAA at an early stage of ripening, together with activated SA, jasmonates and IAA signaling, likely enable a fast defense response leading to grape resistance/ tolerance towards B. cinerea.The balance among the different phytohormones seems to depend on the ripening stage and on the intra-specific genetic background and may be fundamental in providing resistance or susceptibility. In addition, this study indicated the involvement of SA and IAA in defense against necrotrophic pathogens and gains insights into possible strategies for conventional breeding and/or gene editing aiming at improving grape quality and grape resistance against Botrytis cinerea.
Highlights
Hormones play a key role in the development and ripening of grapes and other fleshy fruits as well as in biotic stress response [1,2]
Peppercorn-sized fruits were infected in the field and mock-treated and infected berries were collected at green, veraison and harvest stages for hormone analysis and targeted qPCR analysis of genes involved in hormonal metabolism and signaling
For jasmonate analyses we focused on the bioactive form, jasmonoyl-isoleucine conjugate (JA-Ile) [41], and its biosynthetic precursor 12-oxo-phytodienoic acid (OPDA)
Summary
Hormones play a key role in the development and ripening of grapes and other fleshy fruits as well as in biotic stress response [1,2]. Grape ripening involves important physiological shifts including cell wall remodeling, accumulation of soluble sugars, aroma compounds and anthocyanins, decline of inducible host defense responses, among others. Most of these changes are thought to be regulated by a complex interplay of hormonal signals involving ethylene, ABA, brassinosteroids, jasmonates, polyamines, cytokinins and auxins [1,3]. Fleshy fruits can be classified into two groups, climacteric and nonclimacteric. Climacteric fruits such as tomato present an increase in respiration and ethylene biosynthesis upon initiation of ripening. No single master switch controlling ripening initiation, such as ethylene in climacteric fruits, has yet been identified for non-climacteric fruits [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
