Expression Analysis of Mitogen-Activated Protein Kinases (MAPKs) Gene Family in Grapevine Berries

Plants, as sessile living organisms, are dependent on signalling mechanisms. Mitogen-activated protein kinases (MAPKs) are a highly conserved gene family that take a role in switching an extracellular signal into an intercellular signal. Ripening-related processes in non-climacteric fruits are not as well understood as in climacteric fruits. In this regard, studying MAPKs in grape berries during developmental stages may lead to a better understanding of physiological interactions during commercially relevant stages, such as pigmentation, ripening, and phenolics accumulation in the berries. Each MAPK cascade involves three or four MAPK proteins that facilitate signal transduction by phosphorylation of downstream targets. We examined the relative expression of VvMAP2Ks and VvMAP4Ks in berries at two-weekly intervals, from flowering to over-ripening. Expression analysis of 5 MAP2Ks and 7 MAP4Ks suggested that both gene families may play an active role in development of berries. Expression of VvMAP2K1 showed a correlation with abscisic acid (ABA) and ethylene accumulation. Moreover, the expression pattern of VvMAP2K2 and VvMAP2K3 shows a correlation with auxin, and ABA accumulation respectively. Furthermore, VvMAP2K4 may have a role in berry size increment and halting stomatal development. In addition, VvMAP2K5 may play a role in floral organ development. VvMAP4Ks expression pattern moves them forward to be excellent markers for monitoring the effect of for instance climate changerelated stress on berry development.