锂离子束辐照小麦诱发DNA损伤与特异基因调控网络解析

Analysis of DNA Damage and Specific Gene Regulatory Network Induced by Lithium Ion Beam Irradiation in Wheat(Triticum aestivum L.)

锂(^(7)Li)离子束作为一种新型诱变剂在作物诱变育种中发挥着越来越重要的作用。本研究利用彗星电泳技术探索了^(7)Li离子束辐照小麦诱导的DNA损伤特点,并结合转录组分析初步解析了特异基因表达调控网络。结果表明,与传统诱变因素伽马(γ)射线相比,^(7)Li离子束辐照引起的小麦幼苗生长抑制程度低,幼苗叶脉失绿至开裂。对辐照诱导的差异表达基因进行GO和KEGG功能分析显示,^(7)Li离子束辐照诱导的差异表达基因主要富集在细胞壁合成与代谢和甘油脂类代谢通路,而γ射线辐照诱导的差异表达基因主要富集在光合作用代谢通路中,推测细胞壁合成与代谢和甘油脂类代谢通路途径与响应^(7)Li离子束辐照引起的损伤密切相关,而光合作用代谢途径与响应γ射线辐照引起的损伤密切相关。两种辐射诱导的差异表达基因的转录因子分析结果显示,^(7)Li离子束辐照诱导的MYB、WRKY、bHLH和NAC等转录因子家族可能在响应^(7)Li离子束辐照过程中具有重要作用,^(7)Li离子束辐照特异诱导Whirly家族转录因子调控DNA损伤修复,而γ射线辐照诱导E2F/DP家族转录因子调控DNA损伤修复。

As a new mutagen,lithium(^(7)Li)ion beam plays an increasingly important role in crop mutation breeding.In this study,the characteristics of wheat DNA damage induced by^(7)Li ion beam irradiation treatment were explored by comet assay,and the transcriptional re-programming was preliminarily analyzed by transcriptome analysis.The wheat seedlings showed lower growth inhibition of wheat seedlings caused by^(7)Li ion beam irradiation,but seedlings leaf vein chlorosis to cracking,if compared with those treated by the conventional mutagenic gamma ray(γ).Based on GO and KEGG functional analysis of differentially expressed genes(DEGs)induced by irradiation,DEGs induced by^(7)Li ion beam irradiation were mainly enriched in cell wall synthesis and metabolism and glycerolipid metabolic pathways,while DEGs induced byγray irradiation were mainly enriched in photosynthetic metabolic pathways.That suggested that cell wall synthesis and metabolism and glycerolipid metabolic pathways are likely modulated by^(7)Li ion beam irradiation,while photosynthetic metabolic pathways are likely modified byγray irradiation.Gained from the results of transcription factor analysis of two radiation-induced DEGs,several transcription factor families,such as MYB,WRKY,bHLH and NAC,might specifically respond to^(7)Li ion beam irradiation.The results of this study implied that^(7)Li ion beam irradiation specifically modify the transcriptional re-programming of Whirly family transcription factors to regulate DNA damage repair,while the conventionalγray irradiation likely induced the E2F/DP family transcription factors to regulate DNA damage repair.