摘要：

为了研究GRAS转录因子在大豆胞囊线虫(SCN)胁迫应答中起到重要的作用,将抗病品种东农L-10和感病品种黑农37分别接种SCN 3号生理小种。品红染色确定接虫成功后,提取植株根部进行转录组测序分析。整理共得到20个与SCN相关的候选基因。对编码蛋白的二、三级结构、磷酸化位点、亲水性和疏水性、启动子信息、基因进化关系等进行生物信息学分析研究。取植株的不同组织部位,根、茎、叶提取mRNA并反转录cDNA,对重点的候选基因进行RT-PCR。结果显示:该家族基因与MYB和MYC转录因子存在密切的关系。基因编码蛋白主要以α-螺旋、无规则卷曲为主,二级结构和三级结构高度一致;蛋白为可溶性蛋白,磷酸化位点以丝氨酸为主,RT-PCR表明在植物的不同组织部位均存在一定的表达量,主要以根部为主,在相同的大豆胞囊线虫胁迫下,抗病品种中GRAS表达量显著高于感病品种。上述结果表明,GRAS转录因子为SCN相关的抗性基因,为抗病胁迫响应应答反应提供了重要的基因来源。

关键词: 大豆, GRAS转录因子, RT-PCR, 生物信息学, 大豆胞囊线虫

Abstract:

GRAS transcription factors exist extensively in plant genomes and play an important role in both biological and abiotic stress in plants.To study the significant role of the response to stress in soybean cyst nematode (SCN).The susceptible and disease-resistant varieties Dongnong L-10 and Heinong 37 were inoculated with SCN 3 physiological subspecies respectively.After magenta staining was used to confirm the success of insect grafting,transcriptome sequencing was performed on plant roots.A total of 20 candidate genes related to SCN were obtained.The secondary and tertiary structures,phosphorylation sites,hydrophilicity and hydrophobicity,promoter information and gene evolution relationship of encoded proteins were analyzed and studied in bioinformatics.mRNA was extracted from different tissue parts of the plant,including roots,stems and leaves,and reverse transcription cDNA was performed for key candidate genes by RT-PCR.The results showed that the genes in this family were closely related to MYB and MYC transcription factors.The protein encoded by the gene was mainly α-helix and random coil,and the secondary structure and tertiary structure were highly consistent.Protein was a soluble protein,the phosphorylation site was mainly serine.RT-PCR showed that there were certain expression levels in different parts of plant tissues,mainly in roots.The GRAS expression level of resistant cultivars was significantly higher than that of susceptible cultivars under the same soybean cyst nematode stress.GRAS transcription factors were identified as SCN-related resistance genes,providing an important source of genes for resistance to stress response.

Key words: Soybeans, GRAS transcription factors, RT-PCR, Bioinformatics, Soybean cyst nematode