RESEARCH ARTICLE Regulation of OsmiR156h through Alternative Polyadenylation Improves Grain Yield in Rice

Substantial increases in grain yield of cereal crops are required to feed a growing human population. Here we show that a natural variant of SEMIDWARF AND HIGH-TILLERING (SDT) increases harvest index and grain productivity in rice. Gain-of-function sdtmutation has a shortened polyadenylation tail on theOsmiR156hmicroRNA precursor, which cause the up-regulation ofOsmiR156h. The plants carrying the semidominant sdt allele exhibit re-duced plant height, enhanced lodging resistance, increased tiller numbers per plant, and re-sulting in an increased grain yield. We also show that combining the sdt allele with the OsSPL14WFP allele can be effective in simultaneously improving tillering capacity and pani-cle branching, thereby leading to higher harvest index and grain yield. Most importantly, pyr-amiding of the sdt allele and the green revolution gene sd1 enhances grain yield by about 20 % in hybrid rice breeding. Our results suggest that the manipulation of the polyadenyla-tion status ofOsmiR156 represents a novel strategy for improving the yield potential of rice over what is currently achievable