Carotenoids possess high nutritive values and also serve as anti-aging agents. Human body cannot synthesize these important compounds; hence, dietary intake becomes essential. Different food sources such as carrots are available for good supply of carotenoids in the food. Nonetheless, carrots are available in Pakistan only in winter season at affordable prices for majority of the population. In summer only imported carrots are available at very high prices. Other vegetables such as potatos are available in entire country at affordable prices round the year. Due to low prices, wide acceptability and synchronization with lots of recipes, it is an integral part of the menu of poor as well rich man. Although, it has micronutrients such as Vitamin C, yet devoid of or have carotenoids in traces. Carotenoids present in plants also protect plants from various environmental stresses, too.
Various attempts have been made to improve carotenoid contents of plants such as rice for nutritional purposes through genetic engineering. Potato plants were also improved by transformation of multiple genes of non-plant origin for improvements of cartotenoid contents. Recently, single gene cloned form sweet potato was transformed in potato depicted higher carotenoid contents. Single event of transformation studies is always desirable because it reduces the chances of any pleiotropic effects arising from positional effects of multiple transgene cassettes.
A selection marker gene is used for genetic transformation for selection of putative transforments, which losses it’s utility once transformation is confirmed over multiple generations. However, there are few selection marker genes available which can impart herbicide tolerance in the transformed plants, enabling scientists to improve multiple characteristics of plants for commercial uses.
In the current study, it is proposed to develop transgenic potato (Red skin late blight tolerant cultivar Sarpo Mira ) using Ipomoea batatas IbOr genes (Genbank accession No. HQ828087) under the control of tuber-specific promoter for carotenoid enhancement in tuber along with bar gene encoding phosphinithricin acetyl transferase under CaMV35S promoter for screening of transgenic lines during experimentation yet for non-selective herbicide tolerance in field cultivation.
|