马铃薯块茎变绿中StHY5对龙葵素合成的促进作用

Promotion of StHY5 in the Synthesis of SGAs during Tuber Turning-green of Potato

【目的】马铃薯因采后贮藏、运输及货架摆放等因素,容易造成块茎“绿变”,导致块茎中SGAs大量累积,而HY5是植物中光信号的重要传递因子,研究其在块茎变绿中的作用,为马铃薯采后环节因光照导致的龙葵素积累提供分子基础。【方法】通过基因表达分析、转录组分析、靶向代谢物分析、亚细胞定位、酵母单杂交、双荧光素酶等试验,阐明StHY5在光照后块茎变绿中的作用。【结果】StHY5在薯皮和薯肉中均有表达,但表达模式不同;绿变处理后,薯肉中StHY5的表达水平和SGAs含量的变化一致,与此同时,龙葵素合成基因StSGT1/GAME1和StGAME4表达显著上调;酵母单杂交试验和双荧光素酶试验证明,StHY5可以直接结合StSGT1/GAME1和StGAME4的启动子并激活其表达。【结论】在马铃薯绿变过程中,StHY5通过直接上调StSGT1/GAME1和StGAME4的表达,从而促进SGAs的积累。

【Objective】Post-harvest storage,transportation,shelving,and other factors can lead to the“turning green”of potato,resulting in a significant accumulation of SGAs in tuber.HY5 plays a crucial role as a key mediator of light signals in plants.Investigating its involvement in the turning-green of tuber can establish a molecular foundation for understanding SGAs accumulation induced by light in post-harvest potato.【Method】Through comprehensive gene expression analysis,transcriptome profiling,targeted metabolite analysis,subcellular localization studies,yeast single hybridization and double luciferase experiments,the involvement of StHY5 in tuber turning green following light exposure was preliminarily elucidated.【Result】The StHY5 gene was expressed in both the peel and flesh of potato,but with different expression patterns.During the treatment of potato greening,the expression of the StHY5 gene in potato meat correlated with changes in SGAs content,while the expression of SGAs synthesizing genes StSGT1/GAME1 and StGAME4 was significantly up-regulated.Yeast single hybridization and double luciferase experiments demonstrated that StHY5 directly up-regulated the expression of StSGT1/GAME1 and StGAME4.【Conclusion】During the process of potato greening,the StHY5 plays a role in promoting the accumulation of SGAs by directly up-regulating the expression of StSGT1/GAME1 and StGAME4.This finding provides a solid foundation for further investigation into the function of StHY5 in potato greening.