A biotechnological approach for reduction of cold-induced sweetening in potato tubers

Cold-stored potatoes, in general, produce inferior quality potato chips because of accumulation of reducing sugars at low temperature. Cold-induced hexose accumulation is mediated by breakdown of sucrose by acid invertase in vacuole. Inhibition of vacuolar invertase activity by overexpression of invertase inhibitor has been undertaken to circumvent this problem. Tobacco invertase inhibitor gene (Nt-Inhh) had been cloned by PCR amplification trom the genomic DNA. Nt-Inhh, under the control of either constitutive or tuber-specific promoter, is being used for transformation of Indian potato cultivars. Cloning of this gene analogue from the Gene-RACER library of a wild potato species is also underway. This approach has both industrial and academic implications.