Plant Plastid Engineering

Wani, Shabir H.; Haider, Nadia; Kumar, Hitesh; Singh, N.B.

One of the major advantages of introducing the Bt toxin into the plastid genome is the high levels of toxin accumulation (3% -5% of total leaf protein as compared to > 0.2% of total soluble protein through nuclear genome transformation) [82] . Achievement of stable transformation of the plastid genome and transforming plastids in species other than tobacco (Nicotiana tabacum) are some of the hurdles for widespread adaptation of this technique [81] . Despite of overwhelming odds, many attempts have been made to produce transplastomic plants expressing Bt toxin for increased resistance against insect pests. [83] generated soybean plastid transformants expressing Bacillus thuringiensis Cry1Ab protoxin. Similarly, Chakrabarti et al. [84] reported the control of potato tuber moth (Phthorimaea operculella) by incorporating a truncated Bacillus thuringiensis cry9Aa2 gene in the plastid genome. The authors observed high-level expression (about 10% of total soluble protein) of the cry gene from the plastid genome which resulted in severe growth retardation.