VvMATE1 and VvMATE2 encode putative proanthocyanidin transporters expressed during berry development in Vitis vinifera L.

Abstract

VvMATE1 and VvMATE2 encode putative PA transporters expressed during seed development in grapevine. The subcellular localization of these MATE proteins suggests different routes for the intracellular transport of PAs. Proanthocyanidins (PAs), also called condensed tannins, protect plants against herbivores and are important quality components of many fruits. PAs biosynthesis is part of the flavonoid pathway that also produces anthocyanins and flavonols. In grape fruits, PAs are present in seeds and skin tissues. PAs are synthesized in the cytoplasm and accumulated into the vacuole and apoplast; however, little is known about the mechanisms involved in the transport of these compounds to such cellular compartments. A gene encoding a Multidrug And Toxic compound Extrusion (MATE) family protein suggested to transport anthocyanins-named VvMATE1-was used to identify a second gene of the MATE family, VvMATE2. Analysis of their deduced amino acid sequences and the phylogenetic relationship with other MATE-like proteins indicated that VvMATE1 and VvMATE2 encode putative PA transporters. Subcellular localization assays in Arabidopsis protoplasts transformed with VvMATE-GFP fusion constructs along with organelle-specific markers revealed that VvMATE1 is localized in the tonoplast whereas VvMATE2 is localized in the Golgi complex. Major expression of both genes occurs during the early stages of seed development concomitant with the accumulation of PAs. Both genes are poorly expressed in the skin of berries while VvMATE2 is also expressed in leaves. The presence of putative cis-acting elements in the promoters of VvMATE1 and VvMATE2 may explain the differential transcriptional regulation of these genes in grapevine. Altogether, these results suggest that these MATE proteins could mediate the transport and accumulation of PAs in grapevine through different routes and cellular compartments.

Flavonoid transport mechanisms: how to go, and with whom

“…However, AM1-and AM3-GFP mainly localized to small prevacuole-like vesicles actively moving alongside the central vacuoles in hairy roots, where larger amounts of acylated anthocyanins were produced [4]. Grapevine VvMATE1-and VvMATE2-GFP are localized to the tonoplast and the Golgi complex, respectively [28]. Their expression at the early stages of seed development parallels the accumulation of PAs, suggesting putative functions in PA transport [28].…”

“…Grapevine VvMATE1-and VvMATE2-GFP are localized to the tonoplast and the Golgi complex, respectively [28]. Their expression at the early stages of seed development parallels the accumulation of PAs, suggesting putative functions in PA transport [28]. In M. truncatula, MATE1 transports epicatechin 3-O-glucoside associated with the synthesis of PAs, whereas MATE2 preferentially transports anthocyanin malonates [3,27].…”

“…Flavonoid accumulation-dependent subcellular localization may be a feature of flavonoid transporters, such as grapevine multidrug and toxic compound extrusion (MA-TE)-type anthocyanin transporters anthoMATE1 (AM1) and AM3, VvMATE1 and 2, barrel medic (Medicago truncatula) MtMATE1 and 2, and Arabidopsis MATE transporter TT12 [3,4,[26][27][28][29] (Table 1).…”

The Phenylpropanoid Pathway Is Controlled at Different Branches by a Set of R2R3-MYB C2 Repressors in Grapevine

“…ANR, the putative PA transporters MULTIDRUG AND TOXIC COMPOUND EXTRUSION1 (MATE1) and MATE2 (Pérez-Díaz et al, 2014), and the three glucosyltransferases (GT1, GT2, and GT3) recently proposed to be involved in PA galloylation (Khater et al, 2012). Interestingly, several positive and negative regulators of the flavonoid pathway were found among the genes that were most negatively correlated to MYBC2-L3.…”

The multidrug and toxic compound extrusion (MATE) family in plants

“…Two grapevine MATE transporters, Vitis vinifera MATE1 and 2, with 71.3% and 72.8% to AtTT12, respectively, were also isolated, VvMATE1 as a gene co-regulated with proanthocyanidin biosynthesis genes during the overexpression of VvMYBPA, a transcriptional regulator of the proanthocyanidin pathway ), and VvMATE2 from its sequence similarity with VvMATE1 (Perez-Diaz et al 2014). These VvMATEs differ in localization, with VvMATE1 localizing to tonoplasts and VvMATE2 to the golgi, indicating that these MATE transporters are involved in the accumulation of proanthocyanidins via different pathways (Perez-Diaz et al 2014).…”