VvMJE1 of the grapevine (Vitis vinifera) VvMES methylesterase family encodes for methyl jasmonate esterase and has a role in stress response

Abstract

The known members of plant methyl esterase (MES) family catalyze the hydrolysis of a C-O ester linkage of methyl esters of several phytohormones including indole-3-acetic acid, salicylic acid and jasmonic acid. The genome of grapevine (Vitis vinifera) was found to contain 15 MES genes, designated VvMES1-15. In this report, VvMES5 was selected for molecular, biochemical and structural studies. VvMES5 is most similar to tomato methyl jasmonate esterase. E. coli-expressed recombinant VvMES5 displayed methyl jasmonate (MeJA) esterase activity, it was renamed VvMJE1. Under steady-state conditions, VvMJE1 exhibited an apparent Km value of 92.9 μM with MeJA. VvMJE1 was also shown to have lower activity with methyl salicylate (MeSA), another known substrate of the MES family, and only at high concentrations of the substrate. To understand the structural basis of VvMJE1 in discriminating MeJA and MeSA, a homolog model of VvMJE1 was made using the X-ray structure of tobacco SABP2, which encodes for methyl salicylate esterase, as a template. Interestingly, two bulky residues at the binding site and near the surface of tobacco SABP2 are replaced by relatively small residues in VvMJE1. Such a change enables the accommodation of a larger substrate MeJA in VvMJE1. The expression of VvMJE1 was compared in control grape plants and grape plants treated with one of the three stresses: heat, cold and UV-B. While the expression of VvMJE1 was not affected by heat treatment, its expression was significantly up-regulated by cold treatment and UV-B treatment. This result suggests that VvMJE1 has a role in response of grape plants to these two abiotic stresses.

Identification and analysis of key genes involved in methyl salicylate biosynthesis in different birch species

“…All eight Betula SABP2 displayed the conserved catalytic triad found in the hydrolase domain that was proved in the protein profiling of N. tobacco SABP2 [7]. The conserved catalytic triad is in agreement with previous analyses conducted with Arabidopsis and the grapevine [52,74]. Moreover, the 14 residues observed in Betula SABP2 that contact to SA were consistent with a previous structural study of tobacco SABP2 [5].…”

“…The Betula SABP2 protein sequences displayed multiple domains, including α/β hydrolase-1, α/β hydrolase-4 and Lipase-3. We observed the three conserved amino acids form the catalytic triad that is commonly found in the hydrolase domain and the residues that contact SA [52] (Fig 3).…”

“…Various studies have advocated the importance of SABP2 and SAMT genes in plant developmental stages and signaling cascades [3,7,50,52,68]. Considering their interaction with numerous molecules, SABP2 and SAMT displayed a higher percentage of polymorphism compared to previously analyzed genomic regions in Betula [64,69,70].…”

“…For the first time, the SABP2 enzyme was identified in tobacco [85] and was shown to be a MeSA esterase and an important protein that is required for SAR development [5,7]. In addition, the members of MES/SABP2 family have been isolated and characterized in many other plant species, including the grapevine [52], the potato [86], citrus [80] and poplars [53].…”

Genome-wide characterisation and expression profile of the grapevine ATL ubiquitin ligase family reveal biotic and abiotic stress-responsive and development-related members

“…The publication of the grapevine ( Vitis vinifera ) genome sequence in 2007 facilitated the functional analysis of a number of gene families characterised in other species to determine whether these could be used to improve the performance of this economically important fruit crop33343536373839. The E3 ubiquitin ligase family has not been investigated thus far, and only one grapevine RING-type E3 ubiquitin ligase has been functionally characterised: the EIRP1 protein from the wild species V. pseudoreticulata .…”