Rice is one of major food staples for mankind. Food security is becoming an ever more serious problem under the pressure from continuous population growth. Therefore, it is urgent to secure grain production. Recently, scientists from China National Rice Research Institute (CNRRI) of Chinese Academy of Agricultural Sciences (CAAS) have acquired progress on genetic mechanism of grain yield in rice.

In the study, CNRRI scientists characterized an abnormal flower and dwarf1 (afd1) mutant and AFD1 encoded a DUF640 domain protein. The afd1 mutant exhibited variable characteristics including the dwarfism, long panicles, low seed setting, small grains, and slender and thick hulls. This work would facilitate understanding of the molecular mechanism of vegetative and reproductive development, and provide insight into the functions of AFD1 gene on improving grain yield.

Phenotypes of wild type and afd1 mutant

The afd1 lemma and palea differed significantly from that of the wild type and the afd1 florets showed the slender and thick lemma and palea than that of the wild type. The grain and brown grain in size, 1000-grain weight and weight of 1000 brown grain were markedly decreased in the afd1 mutant. Meantime, the transcript levels of genes involved in regulation of cell proliferation and expansion were upregulated. These results suggested that AFD1 affected the enlargement of the hulls and grain yield.

Floral development of afd1 mutant

This work was supported by grants from National Natural Science Foundation of China (31401464 and 91435105416). The research result has been published online on Journal of Integrative Plant Biology on October 2015 (doi/10.1111/jipb.12441). More details are available on the links bellow: