The Jatropha curcas KASIII gene alters fatty acid composition of seeds in Arabidopsis thaliana

Abstract

Jatropha curcas L. is a perennial, drought-resistant, and non-food oilseed crop. The fatty acid composition of seed oil, especially the ratio of 16- to 18-carbon fatty acids, has a direct impact on the biodiesel quality. In plants, fatty acid chain lengths are mainly determined by the plastidial fatty acid synthase complex which includes three β-ketoacyl-acyl carrier protein synthases (KASs), KASI, KASII, and KASIII. The KASIII is thought to play a rate-limiting role in fatty acid synthesis. Here, we report the functional characterization of a putative JcKASIII gene from Jatropha curcas using Arabidopsis thaliana L. as model system. The transcripts of JcKASIII were detected in all tissues examined and increased in seeds. Overexpression of JcKASIII in Arabidopsis led to an increased content of palmitic acid and a higher ratio of 16- to 18-carbon fatty acids. Moreover, functional analysis of JcAKSIII in kasI or kasII knock down Arabidopsis mutants revealed that the composition of seed oil changed. Taken together, these results suggest that heterologous JcKASIII could function as one of the major regulators of fatty acid composition.

Keywords

• fatty acid synthase
• mutants
• transgenic plants