增强马铃薯茎叶UV-B辐射促进块茎花色苷原位合成的分子机制

With the enhancement of the earth's UV-B radiation, the research on the impact of UV-B on crops is becoming more and more concerned. Our previous studies showed that colored potatoes have stronger UV-B tolerance, and UV-B radiation can also increase the accumulation of tuber anthocyanins. It was demonstrated through grafting techniques that tuber anthocyanin synthesis belongs to in situ dark synthesis. Therefore, how UV-B radiation signal promote the synthesis of tuber anthocyanins has become a scientific problem to be studied after potato stems and leaves were exposed to UV-B radiation. In our project, two red and white tuber potato lines with similar genetic background were used as materials, which were separated from the same seedling. We will alternatively graft the two strains and perform them with UV-B radiation. Then quantify anthocyanin components and quantitative real-time PCR analysis of respective synthetic key enzyme genes are performed, and the differences in gene expression and metabolic pathways of potato response to UV-B stress were analyzed by RNA sequencing. The present study aimed to reveal the molecular regulation mechanism of anthocyanin synthesis in tubers after potato shoot are exposed to UV-B radiation. This project will help people to understand the possible ecological adaptation mechanism of potato under global climate change conditions and provide guidance for the production of potato in the plateau. It also provides a theoretical basis for the role of colored potato anthocyanins in future resistance breeding such as anti-UV-B.

随着地球UV-B辐射的增强，UV-B对农作物的影响研究越来越受到关注。我们前期研究表明，彩色马铃薯具有更强的UV-B耐受性，同时，UV-B辐射也能增加块茎花色苷的积累。通过嫁接表明，花色苷合成属原位暗合成。因此，UV-B辐射马铃薯茎叶是如何促进块茎花色苷合成的机制成为了要究明的科学问题。本项目以从同一个实生株系分离得到红白块茎、遗传背景差异较小的两个品系为研究材料，通过嫁接技术将两个品系交互嫁接后对其进行UV-B胁迫处理，然后对花色苷合成相关的关键酶基因进行定量分析，通过RNA测序分析马铃薯响应UV-B胁迫的基因表达差异和代谢通路变化，旨在揭示UV-B辐射马铃薯叶片引起块茎花色苷合成增加的分子调控机制。项目实施有助于人们解析在全球气候变化背景下马铃薯可能的生态适应机制，为高原马铃薯生产提供指导，并为彩色马铃薯花色苷在未来抗UV-B等抗逆育种中发挥作用提供理论依据。

为了研究UV-B辐射马铃薯茎叶促进块茎花色苷合成的机制，通过嫁接技术证明了块茎花色苷合成属于原位合成，同时发现不同基因型马铃薯同源嫁接可显著提高彩色马铃薯砧木的块茎花色苷含量。并研究了马铃薯块茎花色苷合成、积累、组分及在块茎中的分布规律，进而研究了增强UV-B辐射对马铃薯生长及块茎花色苷组分和含量的影响。对马铃薯块茎花色苷合成相关酶基因进行qPCR分析，表明了StF3H和StDFR可能是增强UV-B辐射提高块茎天竺葵色素含量的关键酶基因。利用转录组学分析增强UV-B辐射下彩色马铃薯叶片与块茎差异基因，初步解析了UV-B辐射马铃薯茎叶促进块茎花色苷合成可能由于植物激素的调节以及植物激素由茎叶长距离移动到块茎进而调控花色苷原位合成，此外，与光反应相关mRNA或蛋白可能由茎叶长距离移动到块茎并调控花色苷合成相关的酶基因或转录因子进一步调控花色苷原位合成，相关验证工作正在进行中。本研究可为在未来全球气候变化背景下马铃薯可能的生态适应机制及高原马铃薯生产提供指导。项目资助发表论文10篇（SCI论文2篇，EI1篇，中文核心论文7篇）。培养博士4名，硕士7名。项目投入经费40.00万元，支出31.659096万元，各项支出与预算相符。剩余经费8.3410万元，剩余经费计划用于本项目后续研究支出。