The processing body component VARICOSE plays a multiplayer role towards stress management in Arabidopsis

Cytoplasmic processing bodies (P bodies) are the sites of messenger RNA decay in eukaryotes. An array of protein components make up the P bodies, whereby these complexes primarily associate with the messenger RNA and subsequently initiates the decay process. In eukaryotes including humans and plants, a few of the P body components are functionally characterized, whereas their role beyond the mRNA still remains to be unraveled. In the present context, the role of Varicose (VCS), a P body component is studied, essentially its involvement in Arabidopsis when exposed to both biotic and abiotic stress. VCS interacts with the Arabidopsis decapping factor5 (DCP5) and both the DCP5 and VCS co-localize in the P bodies when over-expressed. The transgenic Arabidopsis with ectopic expression of VCS confers resistance against Pseudomonas syrinage DC3000. Over-expression of VCS resulted in enhanced basal immunity, as evident from the early activation of pathogenesis-related protein 1 (PR1) with respect to the vcs mutant and the wild-type plants. In comparison with the wild-type plants, the vcs mutant exhibited reduced sensitivity to ABA-mediated inhibition of root length. This primafacie evidence highlights that VCS is involved in regulating seed germination and post-germinative growth in ABA signaling. It is also evident that the VCS promotes early flowering, seedling growth and confers reduced transpiration. Here we demonstrate that the less explored Arabidopsis VCS not only is involved as a component protein of the P bodies but also is involved in regulating multiple physiological processes resulting in tolerance to combined biotic and abiotic stresses. These findings suggest the potential to develop pathogen-resistant, stress-tolerant crop plants through VCS manipulation.