Cultivar-Specific Changes in Primary and Secondary Metabolites in Pak Choi (Brassica Rapa, Chinensis Group) by Methyl Jasmonate

Abstract

Glucosinolates, their hydrolysis products and primary metabolites were analyzed in five pak choi cultivars to determine the effect of methyl jasmonate (MeJA) on metabolite flux from primary metabolites to glucosinolates and their hydrolysis products. Among detected glucosinolates (total 14 glucosinolates; 9 aliphatic, 4 indole and 1 aromatic glucosinolates), indole glucosinolate concentrations (153–229%) and their hydrolysis products increased with MeJA treatment. Changes in the total isothiocyanates by MeJA were associated with epithiospecifier protein activity estimated as nitrile formation. Goitrin, a goitrogenic compound, significantly decreased by MeJA treatment in all cultivars. Changes in glucosinolates, especially aliphatic, significantly differed among cultivars. Primary metabolites including amino acids, organic acids and sugars also changed with MeJA treatment in a cultivar-specific manner. A decreased sugar level suggests that they might be a carbon source for secondary metabolite biosynthesis in MeJA-treated pak choi. The result of the present study suggests that MeJA can be an effective agent to elevate indole glucosinolates and their hydrolysis products and to reduce a goitrogenic compound in pak choi. The total glucosinolate concentration was the highest in “Chinese cabbage” in the control group (32.5 µmol/g DW), but indole glucosinolates increased the greatest in “Asian” when treated with MeJA.

Targeted Metabolomic and Transcriptomic Analyses of “Red Russian” Kale (Brassicae napus var. pabularia) Following Methyl Jasmonate Treatment and Larval Infestation by the Cabbage Looper (Trichoplusia ni Hübner)

“…Alanine was the only amino acid whose concentration differed among the treatment groups (VIP score = 1.4). MeJA treatments have been reported to change the levels of sugars, organic acids, amino acids, and certain GSs in Brassica crops [ 41 , 42 ]. The changes in these primary metabolites were found cutivar-specific in pak choi [ 42 ].…”

“…MeJA treatments have been reported to change the levels of sugars, organic acids, amino acids, and certain GSs in Brassica crops [ 41 , 42 ]. The changes in these primary metabolites were found cutivar-specific in pak choi [ 42 ]. Mono- and disaccharide sugar concentrations were decreased by MeJA spray treatment in “Red Russian” kale, as previously reported [ 42 ].…”

“…To synthesize defense compounds, plants need to utilize energy or precursor compounds including sugars and amino acids [ 39 ]. Reduced sugar concentrations in response to MeJA treatment have been observed in Brassica oleracea and Brassica rapa [ 41 , 42 ]. It also has been suggested that a hidden transcriptional network operates to reduce growth following JA signaling in lieu of depleting energy from carbon sources [ 36 ], thus influencing vegetable eating quality.…”

Health-Promoting Phytochemicals from 11 Mustard Cultivars at Baby Leaf and Mature Stages

“…Glucosinolate hydrolysis products were analyzed using a gas chromatography-mass spectrometry (GC-MS) following the method of Kim et al [ 44 ]. Freeze-dried mustard powder (50 mg) was mixed with 1 mL of deionized distilled water.…”

Effect of the Treatment of the Olive Tree (<i>Olea europaea </i>L.) on the Phenolic Content and Antioxidant Properties in Olive Fruits

“…This is not the first time that varietal differences in the MJ treatment effects are observed. Bibliographic reports have proven that exogenous MJ effect can differ according to the variety in pak choi and plums [30,31]. In summary, the exogenous MJ application to olive tree affects differently to the phenolic composition in olive fruits according to the cultivar.…”