Altering glucosinolate profiles modulates disease resistance in plants

Abstract

SummaryPlant diseases are major contributing factors for crop loss in agriculture. Here, we show that Arabidopsis plants with high levels of novel glucosinolates (GSs) as a result of the introduction of single CYP79 genes exhibit altered disease resistance. Arabidopsis expressing CYP79D2 from cassava accumulated aliphatic isopropyl and methylpropyl GS, and showed enhanced resistance against the bacterial soft-rot pathogen Erwinia carotovora, whereas Arabidopsis expressing the sorghum CYP79A1 or over-expressing the endogenous CYP79A2 accumulated p-hydroxybenzyl or benzyl GS, respectively, and showed increased resistance towards the bacterial pathogen Pseudomonas syringae. In addition to the direct toxic effects of GS breakdown products, increased accumulation of aromatic GSs was shown to stimulate salicylic acid-mediated defenses while suppressing jasmonate-dependent defenses, as manifested in enhanced susceptibility to the fungus Alternaria brassicicola. Arabidopsis with modified GS profiles provide important tools for evaluating the biological effects of individual GSs and thereby show potential as biotechnological tools for the generation of plants with tailor-made disease resistance.

Exogenous glucosinolate produced by Arabidopsis thaliana has an impact on microbes in the rhizosphere and plant roots

“…Differential effects on microbial populations that we observed could result from variable direct susceptibility of populations towards antimicrobial properties of hydrolysis products of glucosinolates (Smith and Kirkegaard, 2002;Kliebenstein et al, 2005;Brader et al, 2006). Beside their antimicrobial effect, glucosinolates and their hydrolysis products could also stimulate microbial growth.…”

“…Kristensen et al (2005) showed that insertion of CYP79A1 gene and accumulation of the novel glucosinolate had only marginal inadvertent effects on the plant transcriptome and metabolome compared with wild type. However, Brader et al (2006) showed that the accumulation of the novel glucosinolate could reduce the induction of jasmonate-mediated pathway but led to increased levels of salicylic acid. These plant defense pathways could modify the soil bacterial community structure (Kniskern et al, 2007;Hein et al, 2008).…”

The Plastidic Bile Acid Transporter 5 Is Required for the Biosynthesis of Methionine-Derived Glucosinolates inArabidopsis thaliana

“…These compounds and their breakdown products, for example, isothiocyanates, protect plants against herbivores and pathogens (Giamoustaris and Mithen, 1995;Mari et al, 1996;Manici et al, 2000;Reymond et al, 2004;Chung et al, 2005;Mewis et al, 2005;Brader et al, 2006) and are known to serve as human anticancer agents (Talalay and Fahey, 2001;Traw et al, 2003;Hayes et al, 2008). After Met-derived glucosinoates, indolic and benzyl glucosinolates are the most abundant glucosinolates in Arabidopsis.…”

Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation

“…4-Methylsulphinylbutyl isothiocyanate was found to inhibit a wide range of fungi and bacteria (Tierens et al, 2001). Increased accumulation of aromatic GSs was shown to stimulate salicylic acid (SA)-mediated defenses, while suppressing jasmonic acid (JA)-dependent defenses (Brader et al, 2006). On the other hand, the GS metabolism was tightly related to some physiological processes under abiotic stresses, such as salinity, drought, heat, light, and nutrient deprivation (del Carmen Martínez-Ballesta et al, 2013).…”

“…Upon tissue damage occurring, GSs are hydrolyzed into bioactive isothiocyanates, thiocyanates, or nitriles by the action of myrosinase (Ratzka et al, 2002;Borgen et al, 2010). These GS hydrolysis products are toxic to fungi, bacterial pathogens, or herbivores (Agrawal and Kurashige, 2003;Wittstock et al, 2003;Brader et al, 2006;Burow et al, 2006;Mumm et al, 2008;Redovniković et al, 2008).…”