2016-3-8 Nature Genetics: A novel gene GLW7 controls large grain
Although genetic diversity has a cardinal role in domestication, abundant natural allelic variations across the rice genome that cause agronomically important differences between diverse varieties have not been fully explored.
Recently, a team led by Bin Han, at the CAS Center for Excellence of Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology (SIPPE), Shanghai Institutes for Biological Sciences reported identiﬁcation of a major QTL (GLW7) from japonica rice, which is responsible for the large grain size in tropical japonica.
The major quantitative trait locus, GLW7, was cloned from japonica rice through an integrating genome-wide association study with functional analysis on grain size in a diverse rice population. GLW7, encoding the plant-specific transcription factor OsSPL13, positively regulates cell size in the grain hull, resulting in enhanced rice grain length and yield. They determine that a tandem-repeat sequence in the 5’UTR of OsSPL13 alters its expression by affecting transcription and translation and that high expression of OsSPL13 is associated with large grains in tropical japonica rice. Further analysis indicates that the large-grain allele of GLW7 in tropical japonica rice was introgressed from indica varieties under artificial selection. Their study demonstrates that new genes can be effectively identified on the basis of genome-wide association data.
(Figure, above, Transcriptional and protein levels of GLW7 in 4 small-grain and 4 large-grain varieties)
This work entitled "OsSPL13 controls grain size in cultivated rice" was published online in Nature Genetics on March 7th, 2016.
This work was supported by grants from the Chinese Academy of Sciences, the National Natural Science Foundation of China and the Ministry of Science and Technology of China.