Key Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, China.
J Exp Bot. 2013 Feb;64(4):1097-109. doi: 10.1093/jxb/ers399. Epub 2013 Jan 16.
The effects of glucose on aliphatic glucosinolate biosynthesis in Arabidopsis thaliana were investigated in this study by using mutants related to aliphatic glucosinolate biosynthesis and regulation, as well as glucose signalling. The results showed that glucose significantly increased the contents of individual and total aliphatic glucosinolates. Expression of MYB28 and MYB29, two key transcription factors in aliphatic glucosinolate biosynthesis, was also induced by glucose. Consistently, the increased accumulation of aliphatic glucosinolates and the up-regulated expression of CYP79F1 and CYP79F2 induced by glucose disappeared in the double mutant myb28myb29. MYB28 and MYB29 synergistically functioned in the glucose-induced biosynthesis of aliphatic glucosinolates, but MYB28 was predominant over MYB29. Interestingly, the content of total aliphatic glucosinolates and the expression level of MYB28 and MYB29 were substantially reduced in the glucose insensitive mutant gin2-1 and the ABA insensitive 5 (abi5-7) mutant compared with the wild type. In addition, total aliphatic glucosinolates accumulated much less in another sugar-insensitive RGS1 (regulator of G-protein signaling 1) mutant (rgs1-2) than in the wild type. These results suggest that glucose-promoted aliphatic glucosinolate biosynthesis is regulated by HXK1- and/or RGS1-mediated signalling via transcription factors, MYB28, MYB29, and ABI5.
本研究通过使用与脂肪族芥子油苷生物合成和调控以及葡萄糖信号相关的突变体，研究了葡萄糖对拟南芥脂肪族芥子油苷生物合成的影响。结果表明，葡萄糖显著增加了单个和总脂肪族芥子油苷的含量。两个关键的转录因子 MYB28 和 MYB29 在脂肪族芥子油苷生物合成中的表达也被葡萄糖诱导。一致地，葡萄糖诱导的脂肪族芥子油苷的积累增加和 CYP79F1 和 CYP79F2 的上调表达在 myb28myb29 双突变体中消失。MYB28 和 MYB29 在葡萄糖诱导的脂肪族芥子油苷生物合成中协同作用，但 MYB28 比 MYB29 占主导地位。有趣的是，与野生型相比，葡萄糖不敏感突变体 gin2-1 和 ABA 不敏感 5 （abi5-7）突变体中的总脂肪族芥子油苷含量和 MYB28 和 MYB29 的表达水平显著降低。此外，另一个糖不敏感的 RGS1（G 蛋白信号调节因子 1）突变体（rgs1-2）中的总脂肪族芥子油苷积累比野生型少得多。这些结果表明，葡萄糖促进的脂肪族芥子油苷生物合成是通过 HXK1-和/或 RGS1 介导的信号转导通过转录因子 MYB28、MYB29 和 ABI5 来调节的。
