Cytokinin in rice

More than half the world depends on rice for daily sustenance, making it one of the most important crops for humanity. The US is a top producer of rice, which is grown mainly in Arkansas, Louisiana, Texas, Louisiana, and California. Improving rice plant productivity, its ability to resist disease, its tolerance for stress, and the nutritional quality of rice grains will have huge positive impact in United States and beyond.

The grain-producing organ in rice is the inflorescence, called a panicle, which consists of a central stem that produces several primary branches and then halts growth. Flowers form on the primary branches, which also produce secondary branches, which in turn form even more flowers. If all goes well, each flower becomes a single grain of rice. Thus, the number and size of branches dictate the number of flowers produced per plant, which in turn dictate the amount of rice produced on a plant.

Cytokinin helps to regulate the number of flowers that form on the rice panicle as well as the size of rice grains.  Since 2011, we have been working with the groups of Joe Kieber (UNC Chapel Hill) and Eric Schaller (Dartmouth) to find out how cytokinin hormones regulate productivity of the rice plant.