Abstract

Jatropha curcas L. is one of the economic crops that are cultivated for biodiesel production. Here, the fatty acid and protein profiles of J. curcas kernels were evaluated during their development. The fruits were divided into eight developmental stages (stages I to VIII) based on their age and morphology. The fatty acid content was analyzed at each stage using gas chromatography after conversion to methyl esters. Fatty acid levels were found to differ between all eight developmental stages, although the major fatty acid in each stage was oleic acid followed by linoleic, palmitic and stearic acids, respectively, except in stage I where linoleic acid was more common than oleic acid. All fatty acids showed a maximum content at stage III, a rapid decline at stage IV and another peak at stage VII before declining. Significant changes were found in the relative abundance of 22 proteins during seed development, of which the expression levels for transcripts encoding for four of these proteins, acetyl CoA carboxylase, phosphoenolpyruvate carboxylase, mercaptopyruvate sulfurtransferase and 4-coumarate: coenzyme A ligase, as evaluated by quantitative RT-PCR, were altered between the developmental stages of the kernels in a broadly similar pattern as the level of most fatty acids.

Key words: Jatropha curcas L., FAME, ACCase, PEPC, MST, 4CL, quantitative real time PCR.