Researchers Find Out Why Rice Can't Get Along with Other Plants

Researchers in the Jander laboratory at Boyce Thomson Institute for Plant Research (BTI) have discovered a new compound in certain rice varieties that may slow the growth of nearby plants. The research team, composed of researchers from the Chinese Academy of Sciences, Yamagata University and Kyoto University in Japan, and Cornell University, identified the compound, called b-tyrosine. It curtails root growth in other plants in laboratory tests, and may also have antibacterial properties.

According to BTI Professor Georg Jander, b-tyrosine was completely unknown as a rice metabolite or even as a plant metabolite. He suspects that rice plants use b-tyrosine for allelopathy. b-tyrosine could reduce root growth in multiple different plant species. Rice varieties that generate b-tyrosine, as well as other grasses, were immune to its effects, but the compound was especially effective against dicots.

The researchers used genetic mapping to show that b-tyrosine biosynthesis is encoded on rice chromosome 12, where they discovered the responsible gene, called TAM1. It encodes tyrosine aminomutase, an enzyme that converts a-tyrosine into b-tyrosine. They also found b-tyrosine in a majority of the japonica, or short-grain, varieties that they tested, but the compound was absent in the long grain indica and aromatic varieties.

For more information, read the news release at the BTI website.