紫花苜蓿MtNAC51转录因子生物信息学和表达特性分析

Bioinformatics and Expression Specificity Analysis of MtNAC51 Transcription Factor in Medicago sativa L.

NAC是植物特异性转录因子其家族基因功能丰富,参与植物生长发育过程中的多种生物学过程,包括生殖器官和营养器官的发育、侧根形成、激素传导、组织衰老、以及生物和非生物胁迫应答等。本研究从苜蓿转录组文库中筛选出1条NAC基因序列。结果预测表明,该NAC转录因子位于苜蓿第四条染色体上,编码360个氨基酸,分子量40 556.60 Da。理化性质分析显示,MtNAC51 (Medtr4g108760.1)蛋白是一个的亲水性蛋白,在N端具有一段保守结构域。在蛋白质二级结构预测中,无规则卷曲占比列最大,系统进化树分析表明,MtNAC51与同为豆科红车轴草TpNAC亲缘关系最近。通过顺式作用元件预测发现:该基因上游2 000 bp启动子序列中存在许多非生物胁迫响应元件,推测其对逆境胁迫有调节作用。实时荧光定量PCR分析显示,MtNAC51基因能够被低温、碱胁迫和干旱诱导表达。本研究表明苜蓿NAC51基因可能参与苜蓿的逆境响应,通过调控抗逆基因的表达来提高植物的抗逆性。

NAC is a plant-specific transcription factor which family genes are rich in functions and participate in a variety of biological processes in plant growth and development, including the development of reproductive and vegetative organs, lateral root formation, hormone conduction, tissue aging, and biological and abiotic stress responses. In this study, one NAC gene sequence was screened from the Medicago sativa transcriptome library.The results indicate that the NAC transcription factor distributed on the fourth chromosome of Medicago sativa,encoding 360 amino acids with a molecular weight of 40 556.60 Da. Physicochemical analysis showed that Mt NAC51(Medtr4 g108760.1) was a hydrophilic protein with a conserved domain at the N-terminal. the random coil occupy a relatively large proportion of Protein Secondary Structure Prediction(PSSP). Phylogenetic tree analysis concluded that MtNAC51 was closely related to TpNAC, It was predicted by homeopathic elements that there was a homeo pathic element of abiotic stress in the 2 000 bp promoter sequence upstream of the gene. It is speculated that it has a regulatory effect on stress. Quantitative analysis of fluorescence showed that MtNAC51 gene can be induced by low temperature, alkaline stress and drought. This study demonstrates that NAC51 gene of Medicago sativa may participate in Medicago sativa stress response and enhance the plant’s resistance by regulating the expression of stress-resistant genes.