High Beta-Carotene Rice in Asia: Techniques and Implications

Vitamin A deficiency is one of the major problems not only in Asia but also in many countries worldwide. It seriously affects the reproductive and immune systems and mostly leads to blindness in children, maternal mortality, and ultimately death. Its deficiency is widespread among the poor whose dietary source is based mostly on rice or other carbohydrate-rich food, because rice is devoid of vitamin A. So, the concept was perceived to provide the supplementary vitamin A in their staple food, rice. Initially, vitamin-A overproducing Golden Rice developed by inserting only two genes, a plant phytoene synthase (PSY) gene from daffodil (Narcissus pseudonarcissus) and the carotene desaturase (CRTI) gene from the bacterium Pantoea ananatis. The vitamin A derived initially in the first phase (Golden Rice 1, GR1) was not sufficient. So, the second generation Golden Rice (GR2) was developed by overexpressing Zea mays PSY gene regulated under maize polyubiquitin promoter in place of daffodil PSY. The GR2 brought a remarkable improvement by accumulating high quantity of carotenoids (up to 37 μg/g) and β-carotene (31 μg/g), which is enough for vitamin A enrichment. Bioavailability studies showed that around 60 g of rice could be sufficient for 50–60 % daily recommended quantity of vitamin A in children which is enough to prevent death and blindness. Effort is under way for introgression of GR2 into the popular indica varieties with confined field trials in some countries. However, there are pro- and anti-lobby for this rice because it is a GM crop; hence, it has not reached the farmers and common man yet. In this chapter, an attempt was made to discuss the details of the techniques and implications of high beta-carotene in rice on Asian context.