Quiescence in rice submergence tolerance: an evolutionary hypothesis.

Area of Science:

• Plant genetics
• Crop science
• Evolutionary biology

Background:

• Rice (Oryza sativa) exhibits varied submergence tolerance, linked to the SUB1A gene.
• The SUB1A gene is present in AA genome wild rice, landraces, and O. sativa.
• CC genome wild rice also shows submergence tolerance, indicating diverse genetic mechanisms.

Purpose of the Study:

• To investigate the evolutionary origin and introgression of the SUB1A gene in rice.
• To explore the geographical spread of submergence tolerance traits in rice.
• To understand alternative submergence tolerance mechanisms in different rice genome types.

Main Methods:

• Phylogenetic analysis of rice species.
• Geographical and historical data analysis.
• Comparative genomics of AA and CC genome wild rice.

Main Results:

• Hypothesized introgression of SUB1A-1 from wild rice into O. sativa.
• Likely origin of SUB1A-1 introgression in the Ganges Basin.
• Evidence of SUB1A-1 spread via human migration in South Asia.
• Absence of SUB1A in CC genome wild rice with submergence tolerance.

Conclusions:

• The SUB1A-1 gene was likely introgressed from wild rice into domesticated rice.
• The Ganges Basin is a probable center for SUB1A-1 introgression.
• Human migration facilitated the spread of submergence tolerance.
• CC genome wild rice possesses distinct submergence tolerance mechanisms.