Genetically-modified (GM) potatoes are likely to be on your plates soon. The Shimla-based Central Potato Research Institute (CPRI) has developed GM potato varieties with the Ama1 gene acclaimed for improved nutritional efficiency, that with RB gene for late blight resistance, and along with the Bt potato for insect resistance. The institute has also developed transgenic potatoes for reduction of cold-induced sweetening.
?All these GM potato varieties are in advanced stages and ready for limited field trials under the Review Committee on Genetic Manipulation (RCGM),? said CPRI director SK Pandey. India has joined Global Potato Genome Sequencing Project which was initiated in mid-2006 and coordinated by Netherland-based Waggeningen University.
Ama1, a storage albumin protein gene sourced from amaranthus hypochondriacus by the Delhi University at its south Delhi campus, has been used by CPRI to develop a GM potato variety in collaboration with Delhi-based National Institute for Plant Genome Research. CPRI has claimed that the protein content in this GM potato variety has increased by 40%.
For late blight resistance, the RB gene cloned from S bulbocastanum by the University of Wisconsin, has been used by CPRI under the collaborative Agricultural Biotechnology Support Project-II for developing promising genotypes by genetic transformation and by crossing with RB-transgenic Katahdn lines. CPRI, along with the National Research Centre on Plant Biotechnology had developed transgenic lines of four potato cultivars encoding the synthetic cry1 Ab gene of bacillus thuringgiensis (Bt).
According to CPRI?s SK Chakrabarti, though reduction in leaf mining was observed in GM varieties Kufri Badshah and Kufri Lauvkar, they failed to show any appreciable gain of resistance. In the meantime, cry9 Aa2 proved to be the most effective Bt toxin for the potato tuber moth (PTM). A plastid transformation vector encoding cry9 Aa2 gene was designed and transplastomic tobacco lines expressing this gene showed high levels of resistance to PTM.
Four selected transgenic lines of Kufri Chipsona-1 expressing Ni-Inhh gene have been developed by CPRI for reducing cold-induced sweetening in storage. The reduction of cold-induced sweetening has been attempted by inhibiting the activity of potato vacuolar invertase through over-expression of tobacco invertase inhibitor, Ni-Inhh, under the control of constitutive promoter, CaMV 35S.
This process was earlier attempted with the popular potato variety, Kufri Badshah, but with not much success.
Kufri Chipsona-1 has been made an industrial product for processing. This variety has been subjected to another genetic modification by RNAi-mediated post-transcriptional silencing of the vacuolar acid invertase gene (INV) through introduction of introns containing inverted repeat gene construct (iIR-INV).
CPRI has developed the GM variety, Kufri Badshah, with resistance to apical leaf curl virus. The replication-associated protein gene, ACI of the virus was used to obtain pathogen-derived resistance. GM Kufri Sutlej and Kufri Pukhraj were been developed by inserting glgC gene of Eschlricha coli for increasing starch content. To produce dwarf plants, the GA20 oxidase gene has been inserted in Kufri Surya and Kufri Himalini.
The Institute of Himalayan Bioresorce Technology under the CSIR system has developed GM Kufri Giriraj by inserting a thaumatin-like protein (TLP) gene from Camellia sinensis for developing resistance to drought. It has also inserted cytosolic Cu-Zn superoxide dismutase gene from Potentilla astrosanguinea with the promoter CaMV 35S in Kufri Sutlej for making it resistant to drought and salinity.