Development of high-lysine rice via endosperm-specific expression of a foreign LYSINE RICH PROTEIN gene. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Liu, Xin; Zhang, Cuicui; Wang, Xiurong; Liu, Qiaoquan; Yuan, Dingyang; Pan, Gang; Sun, Samuel; Tu, Jumin
• Is Part Of: BMC plant biology. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 13
• Publication Date: 2016-12
• Subjects: Lysine -- LYSINE RICH PROTEIN (LRP) -- Rice (Oryza sativa L.) -- High-lysine rice; Plant molecular biology -- Periodicals; Botany -- Periodicals; 580.5
• DOI: 10.1186/s12870-016-0837-x
• Languages: English
• ISSNs: 1471-2229

Abstract

Abstract Background Lysine (Lys) is considered to be the first limiting essential amino acid in rice. Although there have been extensive efforts to improve the Lys content of rice through traditional breeding and genetic engineering, no satisfactory products have been achieved to date. Results We expressed aLYSINE-RICH PROTEIN gene (LRP ) fromPsophocarpus tetragonolobus (L.) DC using an endosperm-specificGLUTELIN1 promoter (GT1) in Peiai64S (PA64S), an elite photoperiod-thermo sensitive male sterility (PTSMS) line. The expression of the foreign LRP protein was confirmed by Western blot analysis. The Lys level in the transgenic rice seeds increased more than 30 %, the total amount of other amino acids also increased compared to wild-type. Persistent investigation of amino acids in 3 generations showed that the Lys content was significantly increased in seeds of transgenic rice. Furthermore, Lys content in the hybrid of the transgenic plants also had an approximate 20 % increase compared to hybrid control. At the grain-filling stage, we monitored the transcript abundance of many genes encoding key enzymes involved in amino acid metabolism, and the results suggested that reduced amino acid catabolism led to the accumulation of amino acids in the transgenic plants. The genetically engineered rice showed unfavorable grain phenotypes compared to wild-type, however, its hybrid displayed little negative effects on grain. Conclusions Endosperm-specific expression of foreignLRP significantly increased the Lys content in the seeds of transgenic plant, and the the Lys increase was stably heritable with 3 generation investigation. The hybrid of the transgenic plants also showed significant increases of Lys content in the seeds. These results indicated that expression ofLRP in rice seeds may have promising applications in improving Lys levels in rice.