Omics of Plastoglobule Lipid Droplets from the “Resurrection Plant” Eragrostis nindensis

Abstract

Eragrostis nindensis is a perennial grass species which grows in semiarid regions. As a resurrection plant, E. nindensis survives extended desiccation through massive remodeling of membranes and molecular machinery, including a nearly complete dismantling of photosynthetically-active thylakoid membranes. Growing evidence has implicated plastoglobule lipid droplets of chloroplasts as mediators of thylakoid membrane remodeling and ultrastructural analysis demonstrates these plastoglobules swell immensely in size as E. nindensis enters desiccation. This has led us to hypothesize a central role for plastoglobules in the remodeling of the thylakoid during entry into and exit from desiccation. To test this hypothesis and establish the functional role(s) of plastoglobules in the survival of severe drought, we have compared the quantitative and qualitative protein and prenyl-lipid composition of isolated plastoglobule and thylakoid samples during a desiccation time course. Preliminary data shows anticipated changes in the prenyl-lipids from thylakoid and plastoglobules. Proteomics data also indicate some interesting changes in proteome during different stages of the desiccation and “resurrection”. Results from the current research could be used in development of crops with improved stress resilience and provide a framework for future studies of plastoglobules in plant species