Department of Plant Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Science. 2013 Jul 12;341(6142):175-9. doi: 10.1126/science.1240230. Epub 2013 Jun 20.
Steroidal glycoalkaloids (SGAs) such as α-solanine found in solanaceous food plants--as, for example, potato--are antinutritional factors for humans. Comparative coexpression analysis between tomato and potato coupled with chemical profiling revealed an array of 10 genes that partake in SGA biosynthesis. We discovered that six of them exist as a cluster on chromosome 7, whereas an additional two are adjacent in a duplicated genomic region on chromosome 12. Following systematic functional analysis, we suggest a revised SGA biosynthetic pathway starting from cholesterol up to the tetrasaccharide moiety linked to the tomato SGA aglycone. Silencing GLYCOALKALOID METABOLISM 4 prevented accumulation of SGAs in potato tubers and tomato fruit. This may provide a means for removal of unsafe, antinutritional substances present in these widely used food crops.
甾体糖苷生物碱（SGAs），如茄科植物（如马铃薯）中的α-茄碱，是人类的抗营养因子。通过对番茄和马铃薯的比较共表达分析，并结合化学分析，揭示了参与 SGA 生物合成的一系列 10 个基因。我们发现其中 6 个基因存在于 7 号染色体上的一个簇中，而另外 2 个基因位于 12 号染色体上的一个重复基因组区域中相邻。经过系统的功能分析，我们提出了一个从胆固醇到与番茄 SGA 苷元相连的四糖部分的修订版 SGA 生物合成途径。沉默 GLYCOALKALOID METABOLISM 4 可防止马铃薯块茎和番茄果实中 SGA 的积累。这可能为去除这些广泛使用的粮食作物中存在的不安全、抗营养物质提供了一种方法。
