Ultraviolet radiation exposure time and intensity modulate tomato resistance to herbivory through activation of jasmonic acid signaling

Abstract

Supplemental ultraviolet radiation increases tomato resistance to thrips herbivory through activation of jasmonic acid signaling, and without changes in the plant metabolome or the density of type-VI trichomes and their associated volatiles.

Ultraviolet radiation enhances salicylic acid-mediated defense signaling and resistance to Pseudomonas syringae DC3000 in a jasmonic acid-deficient tomato mutant

“…15 We did metabolomics, hormone and gene expression analyses, and used the cultivar 'Moneymaker', the tomato mutants defenceless-1 (def-1), impaired in jasmonic acid (JA) biosynthesis, odorless-2 (od-2), defective in the production of functional type-VI trichomes, and their wild-type 'Castlemart', to demonstrate that UV-mediated induction of tomato resistance to thrips was not explained by changes in the leaf metabolome or trichome-mediated defenses, but probably by the activation of JA signalling. 15 UV enhanced constitutive levels of JA-isoleucine (JA-Ile) and expression of JA-responsive genes, but it also induced SA signaling, before thrips herbivory. 15 In the present study, we have further investigated whether UV promotes a stronger tomato defense response after thrips infestation.…”

Ultraviolet radiation modulates both constitutive and inducible plant defenses against thrips but is dose and plant genotype dependent

“…This suggests a UV dose-dependent effect on leaf production of phenolics. Indeed, we have recently reported that exposure to low levels of supplemental UV (A + B) (i.e., 30 min day −1 , 0.34 kJ m −2 day −1 ) did not significantly alter the production of the main phenolic components of tomato leaves, i.e., rutin and chlorogenic acid (Escobar-Bravo et al 2019a). Experimental conditions such as photosynthetically active radiation (PAR) levels and temperature might modulate UV-associated plant responses (Cen and Bornman 1990;Gӧtz et al 2010).…”

“…The fact that this UV dose-dependent effect was only evident in this genotype might be explained by a higher sensitivity to UV in comparison with the other chrysanthemum cultivars. UV sensitivity can be correlated with differences in anatomical and biochemical leaf traits, including thickness, trichomes and composition and concentration of UV-absorbing compounds (Murali et al 1988;Yan et al 2012;Escobar-Bravo et al 2019a). Further analysis to determine whether these parameters can determine differences in chrysanthemum responses to UV are thus needed.…”

“…Fluctuations in light influence plant physiology, and plant adaptive responses to biotic stresses, modulating the plant interactions with herbivorous enemies. Both light quantity and quality have been shown to alter plant constitutive and inducible defenses against arthropod herbivores (Escobar-Bravo et al 2018, 2019a. In particular, variation in ultraviolet radiation (λ 290-400 nm) levels, a relatively small component of the solar light spectrum reaching the terrestrial ecosystems, has been reported to affect plant protection against herbivory (Ballaré 2014).…”

“…This has led to the conception of UV-B as an 'eustress,' a positive form of stress with beneficial effects on plant health and adaptation to more severe stress conditions (Wargent and Jordan 2013). Indeed, UV-B exposure has been shown to confer cross-tolerance to light stress, drought and high temperatures (Wargent et al 2011(Wargent et al , 2015Robson et al 2015;Escobar-Bravo et al 2017a) and to promote plant resistance to aboveground arthropod herbivores (Foggo et al 2007;Demkura et al 2010;Kuhlmann and Müller 2010;Đinh et al 2013;Zavala et al 2015;Dillon et al 2018a, b;Escobar-Bravo et al 2019a). In addition to UV-B, UV-A has beneficial effects on plants by stimulating seed germination, photosynthesis and growth (Li and Kubota 2009;Mariz-Ponte et al 2018), although these effects are environment and genotype dependent (Verdaguer et al 2017).…”