摘要
NAC转录因子是植物中一个大的基因家族,在调控植物生长发育、信号传导、逆境胁迫响应等方面起重要作用。前期研究中,从芒果成花基因酵母文库筛选中分离获得1个NAC基因,命名为MiNAC7,本研究对该基因的生物信息学、表达模式和基因功能进行分析。生物信息学分析表明:MiNAC7基因位于10号染色体上,有4个内含子,5个外显子;MiNAC7基因编码区长度为1137 bp,编码379个氨基酸,理论等电点为4.88,蛋白质分子量为93.41 kDa,氨基酸序列中含有1个NAM保守结构域。系统进化树分析表明,芒果MiNAC7与阿月浑子PvNAC26亲缘关系最接近,同源性最高,氨基酸序列相似性为69.64%。启动子序列分析显示,MiNAC7基因的启动子区域包含光响应元件、赤霉素响应元件以及生长素响应元件等。表达分析显示,MiNAC7基因在童期组织的茎与芽中表达水平较高,在叶中表达很低,在成年期组织的茎中表达水平较高,在花和叶中表达很低。同时发现MiNAC7基因在营养生长期的叶片中表达水平较高,在成花转变期和花发育期的叶片中表达水平很低。超量表达的MiNAC7基因诱导转基因拟南芥出现晚花表型,在超量表达MiNAC7基因的拟南芥中显著降低了促花基因AtFT和AtAP1的表达水平,而AtFLC晚花基因的表达水平显著提高。逆境胁迫处理显示,超量表达MiNAC7基因的拟南芥提高了对干旱和盐的抗性,提高了对GA_(3)的抗性,但对ABA更敏感。本研究表明,芒果MiNAC7基因不仅影响成花也参与对非生物胁迫的应答,为深入研究MiNAC7基因参与调控芒果开花和逆境胁迫应答的基因调控网络奠定基础。
NAC transcription factors are a large gene family in plants which play important roles in regulating plant growth and development,signal transduction,stress response,etc.In the previous study,the NAC gene,named MiNAC7,was isolated by the yeast two-hybrid system.In this study,the bioinformatics,expression patterns and gene functions of genes were studied.Bioinformatics analysis showed that the MiNAC7 gene was located on chromosome 10,with 4 introns and 5 exons.The length of the coding region of the MiNAC7 gene was 1137 bp,encoding 379 amino acids,the theoretical isoelectric point was 4.88,the molecular weight of the protein was 93.41 kDa,and the amino acid sequence contained a conserved NAM domain.Phylogenetic tree analysis showed that mango MiNAC7 and pistachio PvNAC26had the closest genetic relationship and the highest homology,and the amino acid sequence similarity was 69.64%.Promoter sequence analysis showed that the promoter region of the MiNAC7 gene contained light response elements,gibberellin response elements and auxin response elements.Expression analysis showed that the expression level of the MiNAC7 gene was high in the stems and buds of juvenile tissues,low in flowers,high in the stems of adult tissues,and low in flowers and leaves.At the same time,it was found that the MiNAC7 gene maintained a high expression level in the leaves at the vegetative growth stage and a low expression level in the leaves at the flowering transformation stage and flower development stage.Overexpression of the MiNAC7 gene led to a late-flowering phenotype in transgenic Arabidopsis.The overexpression of the MiNAC7 gene in Arabidopsis significantly reduced the expression level of the floral-promoting genes AtFT and AtAP1,while the expression level of the late-flowering gene AtFLC was significantly increased.Stress treatment showed that Arabidopsis with excessive expression of the MiNAC7 gene improved its resistance to drought and salt and improved its resistance to GA_(3) but was more sensitive to ABA.This study shows that th
作者
黄星
徐欢欢
黎开奖
何新华
夏黎明
陆婷婷
梁容真
罗聪
HUANG Xing;XU Huanhuan;LI Kaijiang;HE Xinhua;XIA Liming;LU Tingting;LIANG Rongzhen;LUO Cong(College of Agriculture,Guangxi University/State Key Laboratory for Protection and Utilization of Subtropical Agricultural Bio-logical Resources/Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety,Nanning,Guangxi 530004,China)
出处
《热带作物学报》
CSCD
北大核心
2023年第11期2256-2264,共9页
Chinese Journal of Tropical Crops
基金
国家现代农业产业技术体系岗位项目“广西芒果创新团队栽培与病虫害防治”(No.nycytxgxcxtd-2021-06-2)
科技先锋队‘强农富农’‘六个一’专项行动(No.202204)
广西创新驱动发展专项(桂科AA22068098-2)。
