ISSN: E 2347-226X, P 2319-9857
Role of Plant Fatty acid Elongase (3 keto acyl-CoA Synthase) gene in Cuticular Wax Biosynthesis
Plant surfaces are ensheathed by cuticular wax, amorphous intra-cuticular embedded in cutin polymer and crystalloid epi-cuticular that imparts a whitish appearance, confers drought resistance by reducing stomatal transpiration and also protects from U.V Radiation, phytophagous insects etc. Very long chain fatty acids acts as precursors for cuticular wax bio-synthesis. Wax bio-synthesis begins with fatty acid synthesis in the plastid (de novo synthesis of C16 and C18) and elongation of fatty acids in endoplasmic reticulum (C20 – C34) by four distinct enzymes 3-ketoacyl-CoA synthase, 3-ketoacyl-CoA reductase, 3-hydroxacyl-CoA dehydratase, trans-2,3-enoyl-CoA reductase (KCS, KCR, HCD, ECR). The KCS, a fatty acid elongase, determines the chain length and substrate specificity of the condensation reaction, a rate limiting step and the subsequent elongated products alkanes, aldehydes, primary alcohols, secondary alcohols, ketones and wax esters. 21 KCS genes were annotated in Arabidopsis thaliana Genome of which some KCSs were identified involved in cuticle formation (CER6) (CUT1), KCS1, KCS2, (DAISY), KCS20 and FDH).The current review will focus on the bio-chemical, genetic and molecular approaches on KCSs genes, predominantly KCS1 in plants particularly useful in identifying and characterizing gene products involved in wax bio-synthesis, secretion and function for developing transgenic crops that combat various stresses. INTRODUCTION
Uppala Lokesh, Kurnool Kiranmai, Merum Pandurangaiah, Owku Sudhakarbabu, Ambekar Nareshkumar and Chinta Sudhakar