An allelic variant of GAME9 determines its binding capacity with the GAME17 promoter in the regulation of steroidal glycoalkaloid biosynthesis in tomato. (14th January 2020)

• Record Type: Journal Article
• Authors: Yu, Gang; Li, Changxing; Zhang, Lei; Zhu, Guangtao; Munir, Shoaib; Shi, Caixue; Zhang, Hongyan; Ai, Guo; Gao, Shenghua; Zhang, Yuyang; Yang, Changxian; Zhang, Junhong; Li, Hanxia; Ye, Zhibiao
• Editors: Hancock, Robert
• Is Part Of: Journal of experimental botany. Volume 71:Number 9(2020)
• Page Start: 2527
• Page End: 2536
• Publication Date: 2020-01-14
• Subjects: GAME9 -- GAME17 -- genome-wide association study -- tomato -- steroidal glycoalkaloids -- variation; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/eraa014
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : An allelic variant of the transcription factor GAME9 reduces accumulation of toxic steroidal glycoalkaloids in ripe tomato fruit via altered binding to the promoter of a steroidal glycoalkaloid biosynthesis gene. Abstract: Steroidal glycoalkaloids (SGAs) are cholesterol-derived molecules found in the family Solanaceae. SGA content varies among different plant species and varieties. However, the genetic mechanisms regulating SGA content remain unclear. Here, we demonstrate that genetic variation in GLYCOALKALOID METABOLISM 9 ( GAME9 ) is responsible for the variation in SGA content in tomato ( Solanum lycopersicum ). During a sequential analysis we found a 1 bp substitution in the AP2/ERF binding domain of GAME9 . The 1 bp substitution in GAME9 was significantly associated with high SGA content and determined the binding capacity of GAME9 with the promoter of GAME17, a core SGA biosynthesis gene. The high-SGA GAME9 allele is mainly present in S. pimpinellifolium and S. lycopersicum var . cerasiforme populations and encodes a protein that can bind the GAME17 promoter. In contrast, the low-SGA GAME9 allele is mainly present in the big-fruited varieties of S. lycopersicum and encodes a protein that shows weak binding to the GAME17 promoter. Our findings provide new insight into the regulation of SGA biosynthesis and the factors that affect the accumulation of SGA in tomato.