Mechanisms of far-red light-mediated dampening of defense against Botrytis cinerea in tomato leaves. Issue 3 (24th July 2021)

• Record Type: Journal Article
• Authors: Courbier, Sarah; Snoek, Basten L; Kajala, Kaisa; Li, Linge; van Wees, Saskia C M; Pierik, Ronald
• Is Part Of: Plant physiology. Volume 187:Issue 3(2021)
• Page Start: 1250
• Page End: 1266
• Publication Date: 2021-07-24
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1093/plphys/kiab354
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract: Plants detect neighboring competitors through a decrease in the ratio between red and far-red light (R:FR). This decreased R:FR is perceived by phytochrome photoreceptors and triggers shade avoidance responses such as shoot elongation and upward leaf movement (hyponasty). In addition to promoting elongation growth, low R:FR perception enhances plant susceptibility to pathogens: the growth–defense tradeoff. Although increased susceptibility in low R:FR has been studied for over a decade, the associated timing of molecular events is still unknown. Here, we studied the chronology of FR-induced susceptibility events in tomato ( Solanum lycopersicum ) plants pre-exposed to either white light (WL) or WL supplemented with FR light (WL+FR) prior to inoculation with the necrotrophic fungus Botrytis cinerea ( B.c. ). We monitored the leaf transcriptional changes over a 30-h time course upon infection and followed up with functional studies to identify mechanisms. We found that FR-induced susceptibility in tomato is linked to a general dampening of B.c.- responsive gene expression, and a delay in both pathogen recognition and jasmonic acid-mediated defense gene expression. In addition, we found that the supplemental FR-induced ethylene emissions affected plant immune responses under the WL+FR condition. This study improves our understanding of the growth–immunity tradeoff, while simultaneously providing leads to improve tomato resistance against pathogens in dense cropping systems. Abstract : The low red:far-red ratio enhances tomato susceptibility to the necrotrophic fungus Botrytis cinerea via delayed early pathogen detection and dampening of jasmonic acid-mediated defense activation.