苦荞bHLH93转录因子响应铝胁迫的功能研究OA北大核心CSTPCD

[Objective]Buckwheat is an important cereal and economic crop.Compared with other crops,buckwheat has strong aluminum tolerance.A transcription factor FtbHLH93 in response to aluminum stress was identified in transcriptome data of aluminum treatment.Exploring the function of FtbHLH93 will provide ideas and clues for solving the problem of aluminum toxicity in acidic soil and molecular breeding of new varieties of buckwheat with aluminum tolerant,and provide theoretical basis for the molecular mechanism of tolerance aluminum in buckwheat.[Method]The cDNA of Pinkul was used as a template to clone FtbHLH93.qRT-PCR was used to detect the expression of FTbHLH93 in different tissues of Tartary buckwheat and at different time points after aluminum treatment.Yeast system was used to identify the transcriptional activation activity.The localization of intracellular expression was determined by subcellular localization.The flavonoid content of the overexpressed materials was examined,and SOD and POD activities were measured under untreated and Al-treated conditions.The differentially expressed genes were analyzed by transcriptome analysis,potential downstream target genes were screened,and their promoters were predicted.The dual luciferase reporter gene assay was used to verify the results.[Result]The coding region of FtbHLH93 transcription factor was 573 bp in length,encoding 190 amino acid residues.The predicted molecular weight of FtbHLH93 was 21.759 kDa,and its isoelectric point was 8.64.qRT-PCR results showed that FtbHLH93 was highly expressed in roots.The expression level of FtbHLH93 is highest at 24 h after aluminum treatment.FtbHLH93 is localized in the nucleus without self-activating activity.Overexpression of FtbHLH93 in Tartary buckwheat hairy roots enhanced aluminum tolerance,and the activities of SOD and POD were significantly higher than those of the control group.The detection results of flavonoid metabolites in the overexpressed FtbHLH93 hairy roots showed that the contents of rutin,catechin,and fireworks were significantly higher than those of the control group.GO enrichment analysis showed that it was related to metal ion transport and cadmium and manganese ion entries,and KEGG enrichment analysis showed that it was related to ABC transporter.Three genes responsive to aluminum stress may be downstream target genes of FtbHLH93,and co-expression analysis showed that two of the candidate downstream target genes had a similar expression pattern to FtbHLH93.[Conclusion]FtbHLH93 transcription factor may alleviate aluminum toxicity by promoting the accumulation of flavonoids and the increase of SOD and POD activities.FtbHLH93 may act as an upstream regulator to regulate the expression of FtPinG0100930100.01,FtPinG0303102000.01 and FtPinG0403996200.01.