Plant Genomics

Biography

Biography: Bushra Hafeez Kiani

Abstract

The rol ABC genes have been shown to enhance production of secondary metabolites in plants, possibly through stimulation of the defense pathway. This report examines the effect of transformation of A. annua with the rol ABC genes expressing in A. tumefaciens and A. rhizogenes. The artemisinin content, trichome density and expression of key genes in the biosynthetic pathway of artemisinin were measured. Artemisinin content was significantly increased in transformed material of both Artemisia species when compared to un-transformed plants. The artemisinin content within leaves of transformed lines was increased by a factor of ten, indicating that the plant is capable of synthesizing much higher amounts than has been achieved so far through traditional breeding. Expression of all artemisinin biosynthesis genes was significantly increased, although variation between the genes was observed. Cytochrome P450 (CYP71AV1) and aldehyde dehydrogenase 1 (ALDH1) expression levels were higher than that of amorpha-4, 11 diene synthase (ADS). Levels of the trichome development and sesquiterpenoid biosynthetic gene (TFAR1) expression were also increased in all transgenic lines. Trichome density was also significantly increased in the leaves of transformed plants, but no trichomes were found in control roots or transformed roots. The detection of significantly raised levels of expression of the genes involved in artemisinin biosynthesis in transformed roots correlated with the production of significant amounts of artemisinin in these tissues. This suggests that synthesis is occurring in tissues other than the trichomes which contradict previous theories. This elucidation will help to increase production to meet the increasing demand of artemisinin because of its pharmacological importance.