Black nightshade modified for reduced production of endogenous proteinase inhibitors

The genes pin1 and pin2b from Solanum nigrum each codes for a type II  serine proteinase inhibitors (PIN), which block the proteolytic activity of trypsin and chymotrypsin. Plants produce proteinase inhibitors as a strategy to protect themselves against the damage caused by herbivorous insects.

In the genetically modified plants S06-336, S06-353, S06-354 and S06-356 the synthesis of two of the plant's native proteinase inhibitors, PIN1 and PIN2b, is reduced by post-transcriptional gene silencing. For this purpose, an RNAi construct consisting of fragments of the pin1 and pin2b genes  from S. nigrum was developed.

As a result of the genetic modification, the targeted reduction of the production of the PIN2b and PIN1 proteins is expected to reduce the genetically modified plant's defences against herbivory.

Cultivar/breeding line: Sn 30

pSOL3PIN12

Fragments of the proteinase inhibitor genes pin1 and pin2b derived from S. nigrum were linked in a chimeric fragment of 728 bp. The plasmid pSOL3-PIN12 used for transformation includes a construct in which two of these 728 bp fragments 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, 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.