Vitamins are essential micronutrients for both plants and humans. Their antioxidant properties have also been shown to correlate with various stress resistance responses in plants. The project investigates the regulation of vitamins B1 and B6 biosynthesis pathways in cassava and rice and their potential to engineer enhances stress resistance in these two important staple crops.
There has been renewed interest in vitamin B1 and B6 because recent studies suggest that both vitamins reduce reactive oxygen species (ROS) during abiotic stress conditions. Exogenous application of thiamine (vitamin B1) protects plants to pathogen infections and ROS damage. However, the molecular mechanisms underlying these observations have not yet been investigated. Similarly, vitamin B6 has been postulated to efficiently quench ROS comparable to ascorbic acid (vitamin C) and α-tocopherol (vitamin E). There has been some debate as to whether the antioxidant capacity of vitamins is a direct or indirect effect, i.e., can the vitamin quench ROS in vivo (singlet oxygen in particular) or are reported observations the result of modulation of enzymes involved in ROS scavenging that are dependent on the vitamin as a cofactor.
The project investigates the transcriptional regulation of vitamin B1 and B6 biosynthesis pathways during specific biotic and abiotic stresses in rice and cassava, two important staple crops for human nutrition and food security. Identification and characterization of rice and cassava genes involved in vitamin B1 and B6 biosynthesis will be instrumental to generate transgenic plants over-producing these two vitamins. Transgenic lines accumulating high levels of vitamin B1 or B6 will be evaluated for their response to stress conditions.
Vitamin B1 and B6 biosynthesis and accumulation in crops is highly relevant for both plant responses to changing environmental conditions and human nutrition. The use of cassava and rice to study vitamin B1 and B6 biosynthesis under stress conditions will be instrumental to generate cassava and rice with ameliorated agronomical performance and improved vitamin content. The study has the potential to improve vitamin B deficiencies in populations dependent on cassava and rice as staple food.