Reverse Genetic Application in functional study of Arabidopsis thaliana strictosidine synthase Like-6 gene under salt stress

Strictosidine synthase-like (SSL) is a group of gene family in the Arabidopsis thaliana genome, which their orthologous in other plants, such as Catharanthus roseus, are key enzymes in the monoterpenoid indole alkaloid biosynthesis pathway. Arabidopsis SSL6 gene, a member of SSL family, has been induced significantly by various stresses and signaling molecules. In this study, the reverse genetics approaches (T-DNA insertion) are used to determine the function of the SSL6 gene in response to the salt stress. The experiment was conducted using a factorial experiment based on the completely randomized design with two factors and three replications. These factors were included two genotypes (Col-0 and ssl6) and three NaCl treatments (0 mM, 100mM and 200 mM). Compared with the wild-type, the ssl6 mutant shows significantly increased proline accumulation, anthocyanin content and reduced malondialdehyde (MDA) content in response to the salt stress. Real-Time PCR analysis revealed that the expression levels of SOS genes were upregulated significantly in ssl7 compared with the expression in Col-0 in response to 150 mM NaCl at 3 h and 6 h after the treatment. Totally, these results suggest that SSL6 might have a negative regulatory role in response to salt stress in Arabidopsis.