龙葵素是马铃薯产生的天然毒素。马铃薯在采后运输、储藏和销售过程中特别容易绿变、发芽和积累龙葵素，严重影响薯块品质和食用安全。虽然目前已经知道马铃薯龙葵素生物合成途径的9个关键基因成簇串联排列在7号和12号染色体上，并受光照等信号诱导协同表达，但对控制龙葵素生物合成的转录因子及上游信号转导通路还未见报道。申请人前期研究发现雷帕激酶Target Of Rapamycin（TOR）在调控马铃薯块茎绿变、发芽和龙葵素合成过程中发挥着关键作用，而且TOR基因可能通过转录因子ABA insensitive 4 (ABI4)调控龙葵素代谢通路关键基因来影响龙葵素生物合成。基于这些前期研究基础，本项目将利用生物化学、遗传学、分子生物学和代谢组学等方法解析TOR和ABI4互作调控马铃薯采后龙葵素合成的分子机理。研究成果将为马铃薯采后品质保持、食用安全以及分子育种提供新的靶标基因。

Solanine is the natural product generated by potato. Potato tuber greening, sprouting and solanine accumulation can be widely observed during post-harvesting stage. It is well known that an array of 9 key genes that partake in solanine biosynthesis respectively locate as cluster on No.7 and No.12 chromosome and co-express in response to light exposure, but little is known about the transcription factors and signaling transduction pathways involving in solanine biosynthesis. Our previous studies showed that Target of Rapamycin（TOR）plays a key role in cell metabolism and latest studies have shown that potato tuber greening, sprouting and solanine accumulation can be significantly suppressed by TOR inhibitors such as AZD8055 and Torin1. Furthermore, ABA insensitive 4 (ABI4) was identified as a downstream negative effector of TOR signaling to regulate the expression of the key genes involving in sonanine biosynthesis. Based on these observations, we will dissect the underlying molecular mechanism in which TOR may interplay with ABI4 to control the biosynthesis of solanine in potato by integrating the biochemistry, genetics, molecular biology and metabolics approaches. The Project will provide novel target genes for maintaining tuber quality for extending shelf stage and reducing eddible risk through molecular breeding in potato.