Submergence-tolerant varieties released. To date, CURE and its NARES partners have released a total of 21 submergence-tolerant varieties.
List of submergence-tolerant varieties with the sub1 gene released from 2009-2013.
The sub1 gene. Submergence-tolerant rice contains the submergence 1 (SUB1) gene that allows it to survive 10–14 days of complete submergence and to renew growth when the water subsides.
SUB1, or more specifically the Sub 1A gene, is an ethylene-response-factor-like gene that confers submergence tolerance on rice. It acts mainly by decreasing rice sensitivity to ethylene, a plant hormone that promotes processes causing plants to elongate, lose their stored energy, and degrade their chlorophyll.
However, the duration of survival is also influenced by environmental factors such as water turbidity, temperature, and light, and other factors such as seedling age. Plants become more tolerant as they get older.
Countries. India, Bangladesh, Thailand, Indonesia, Cambodia, Myanmar, Nepal, Philippines, and Vietnam