A Variation of Gene expression of Protein Translocon at the Outer Envelope of Chloroplast: a brief overview

Abstract

In plants, the chloroplast is the site for essential functions that are critical for many biosynthetic pathways. Due to the transfer of majority of its genes to the host nucleus during the endosymbiotic event, a host majority of the chloroplast proteins are nuclear encoded and post-translationally targeted into the chloroplast. Thus, protein trafficking into the chloroplast plays a pivotal role in regulation of chloroplast biogenesis. Among the various components of the translocon machinery, the translocon at the outer envelope of chloroplast (TOC) dictate the selectivity of the preproteins that have to be imported into the chloroplast for proper chloroplast function. Studies of the components of the TOC complex suggest that change in expression of the genes for TOC complex critically influence the chloroplast biogenesis and other related plant processes. Owing to the advancement in chloroplast biotechnology and increasing usage of chloroplast as a platform for crop improvement and production of biochemicals, it is of utmost importance to understand the expression pattern of the genes of the TOC complex. Using the publicly available gene expression database, we briefly discuss the expression pattern of the genes of TOC complex at different growth, development and stress conditions. An overview of the gene expression responses of the TOC complex will enhance our understanding of the chloroplast physiology which is fundamentals to chloroplast engineering for crop improvement and its industrial applications.