Development of High-Lysine Rice via Expression of a LYSINE RICH PROTEIN Transgene

Lysine (Lys) is an essential amino acid in rice. There have been efforts on improving Lys content in rice, but no products have been developed to date. Thus, researchers from the Zhejiang University and the Chinese University of Hongkong led by Xin Liu and Cuicui Zhang expressed a LYSINE-RICH PROTEIN gene (LRP) from Psophocarpus tetragonolobus (L.) in Peiai64S (PA64S), an elite photoperiod-thermosensitive male sterility (PTSMS) rice line.

The level of Lys in transgenic rice seeds increased more than 30 percent. The amount of other amino acids also increased compared to wild types. Evaluation of amino acids in 3 generations showed that the Lys content was significantly increased in seeds of transgenic rice. Furthermore, Lys content in the hybrids of these transgenic plants also had significant increases in Lys.

However, the transgenic rice also showed unfavorable grain phenotypes. Researchers then tested the endosperm-specific expression of foreign LRP. This significantly increased the Lys content in the seeds of transgenic plant, and the Lys increase is stably heritable in three generations.

For more information on the study, read the full article in BMC Plant Biology.