Exogenous Methyl Jasmonate Treatment Increases Glucosinolate Biosynthesis and Quinone Reductase Activity in Kale Leaf Tissue

Abstract

Methyl jasmonate (MeJA) spray treatments were applied to the kale varieties ‘Dwarf Blue Curled Vates’ and ‘Red Winter’ in replicated field plantings in 2010 and 2011 to investigate alteration of glucosinolate (GS) composition in harvested leaf tissue. Aqueous solutions of 250 µM MeJA were sprayed to saturation on aerial plant tissues four days prior to harvest at commercial maturity. The MeJA treatment significantly increased gluconasturtiin (56%), glucobrassicin (98%), and neoglucobrassicin (150%) concentrations in the apical leaf tissue of these genotypes over two seasons. Induction of quinone reductase (QR) activity, a biomarker for anti-carcinogenesis, was significantly increased by the extracts from the leaf tissue of these two cultivars. Extracts of apical leaf tissues had greater MeJA mediated increases in phenolics, glucosinolate concentrations, GS hydrolysis products, and QR activity than extracts from basal leaf tissue samples. The concentration of the hydrolysis product of glucoraphanin, sulforphane was significantly increased in apical leaf tissue of the cultivar ‘Red Winter’ in both 2010 and 2011. There was interaction between exogenous MeJA treatment and environmental conditions to induce endogenous JA. Correlation analysis revealed that indole-3-carbanol (I3C) generated from the hydrolysis of glucobrassicin significantly correlated with QR activity (r = 0.800, P<0.001). Concentrations required to double the specific QR activity (CD values) of I3C was calculated at 230 µM, which is considerably weaker at induction than other isothiocyanates like sulforphane. To confirm relationships between GS hydrolysis products and QR activity, a range of concentrations of MeJA sprays were applied to kale leaf tissues of both cultivars in 2011. Correlation analysis of these results indicated that sulforaphane, NI3C, neoascorbigen, I3C, and diindolylmethane were all significantly correlated with QR activity. Thus, increased QR activity may be due to combined increases in phenolics (quercetin and kaempferol) and GS hydrolysis product concentrations rather than by individual products alone.

Foliar application of methyl jasmonate induced physio-hormonal changes in Pisum sativum under diverse temperature regimes

“…Findings by Ku et al (2014) support our results of MeJA increasing endogenous JA under OT. Ku et al (2014) applied exogenous JA to kale plants grown consecutively for two years under open field conditions.…”

“…Findings by Ku et al (2014) support our results of MeJA increasing endogenous JA under OT. Ku et al (2014) applied exogenous JA to kale plants grown consecutively for two years under open field conditions. In the first year, when the plants experienced normal environmental conditions and little stress, they accumulated more endogenous JA in kale apical leaves.…”

Fatty Acids Profile, Phenolic Compounds and Antioxidant Capacity in Elicited Callus of<i>Thevetia peruviana</i> (Pers.) K. Schum

“…4 . This result agree with Gharechahi et al 29 in which MeJA, increase the C18:2 content in hairy root cultures of Silybum marianum L. Furthermore it has been found that JA or MeJA exogenously can induce the biosynthesis of JA endogenously 30 .…”

Glucosinolates, Carotenoids, and Vitamins E and K Variation from Selected Kale and Collard Cultivars

“…Glucosinolate composition in kale and collard has been reported [9,12], but glucosinolate composition in different collard cultivars is still relatively less reported. Additionally, glucosinolate composition can be affected by various biotic and abiotic factors, complicating comparison of the result of different studies.…”

“…The healthpromoting effects of glucosinolates are in fact from their hydrolysis products, and anticarcinogenic activities of such hydrolysis products have been reported in cell culture, preclinical, and clinical studies [3,6,7]. The profile of glucosinolates of kale has been shown to vary depending on crop, cultivar, maturity, or plant tissue [8,9]. However, the glucosinolate profile in collard has only been reported relatively recently and there is a large variation in glucosinolate content, partially due to different cultivars investigated [10][11][12].…”