Black nightshade modified for reduced production of endogenous prosystemin

Black nightshade was modified to reduce the synthesis of the plant's native prosystemin  by post-transcriptional gene silencing using an RNAi construct which was developed from fragments of the prosystemin gene from S. nigrum

The prosystemin gene codes for the 200 amino acid prosystemin peptide, which is the precursor of the active 18 amino acid systemin peptide. Systemin is a signaling molecule which plays an important role in mediating the systemic wound response in plant tissues.

The modification resulted in the targeted reduction of the production of the prosystemin peptide leading to a decrease in the plant's defences against herbivores/pathogen infestation.

Cultivar/breeding line: Sn 30

pSOL3SYS

The plasmid pSOL3SYS used for transformation includes a construct in which two complementary 404 bp fragments of the prosystemin gene (nigpro) derived from S. nigrum were arranged in sense and antisense orientation, separated by a spacer. The 785 bp long third intron of the pyruvate orthophosphate dikinase gene (pdk i3) of Flaveria trinervia (Asteraceae), of which splicing activity is suspected, was used as a spacer. The expression is controlled by the promoter and the termination signal of the 35S gene of cauliflower mosaic virus (CaMV).

The hygromycin phosphotransferase gene (hptII) of Escherichia coli expressed under the control of the promoter and termination signal of the nopaline synthase gene of Agrobacterium tumefaciens was used as a selection marker. The introduced nucleic acid is integrated in the genome of the recipient organism.