烟草MRS2/MGT基因家族的鉴定与表达分析  

Identification and Expression Analysis of MRS2/MGT Gene Family in Tobacco

作　　者：吴题 魏晓玲 冯常青 黄云侠 徐时长 邱福祥 郑英洁 李文卿 何华勤[1] WU Ti;WEI Xiaoling;FENG Changqing;HUANG Yunxia;XU Shichang;QIU Fuxiang;ZHENG Yingjie;LI Wenqing;HE Huaqin(College of Life Science,Fujian Agriculture and Forestry University,Fuzhou 350002;Tobacco Science Research Institute,Fujian Tobacco Monopoly Administration,Fuzhou 350003)

机构地区：[1]福建农林大学生命科学学院,福州350002 [2]福建省烟草专卖局烟草科学研究所,福州350003

出　　处：《中国农学通报》2022年第16期18-26,共9页Chinese Agricultural Science Bulletin

基　　金：福建省烟草专卖局项目“镁营养对福建烤烟生长和品质的影响研究”(20193500002400009)。

摘　　要：为鉴定烟草基因组中的镁转运蛋白(MGT)基因,探讨MGT对烟株镁离子运输的机制,首先以水稻和拟南芥基因组中的镁转运蛋白家族基因为参考序列,应用同源序列比对方法,从烟草基因组中鉴定获得7个NtMGTs,均具有保守的Gly-Met-Asn三肽基序。再设计不同镁供应水平和光强处理的实验,结果发现NtMGTs的表达具有组织特异性且受光诱导表达。强光处理使烟株根中NtMGT1与叶片中的NtMGT2、NtMGT4、NtMGT5的表达量上升。随着镁供应浓度的上升,根系NtMGT1基因表达量提高且与根系镁含量变化趋势一致,推断NtMGT1基因主要介导烟株根系对镁的吸收;而叶片中NtMGT2、NtMGT4与NtMGT5基因表达量先上升后降低,说明3个基因属于高亲和镁离子转运系统。高温强光胁迫下,适当施镁能提高烟株地下部NtMGT1表达,促进根系吸收镁离子;提升地上部NtMGT2、NtMGT4与NtMGT5基因表达,促进镁离子的转运,保障烟株正常的生长发育。研究结果可为烟草生产上合理施镁提供理论指导。To identify magnesium transporter(MGT) gene in tobacco genome and explore the mechanism of magnesium ion transport by MGT in tobacco plant, seven NtMGTs with conservative Gly-Met-Asn tripeptide motifs were identified from tobacco genome by homologous sequence alignment using the magnesium transporter family genes in rice and Arabidopsis genomes as reference sequences. The results showed that the expression of NtMGTs was tissue-specific and light-induced under different magnesium supply levels and light intensities. The expression of NtMGT1 in roots and NtMGT2, NtMGT4 and NtMGT5 in leaves of tobacco plants increased under strong light intensity. With the increase of magnesium supply, the expression of NtMGT1 gene in the root system increased, which was consistent with the change trend of magnesium content in the root system, suggesting that NtMGT1 gene mainly mediated the absorption of magnesium in the root system of tobacco plant. The expression levels of NtMGT2, NtMGT4 and NtMGT5 genes in leaves increased first and then decreased, indicating that the three genes belonged to a high affinity magnesium ion transport system. These results implied that under the stress of high temperature and strong light intensity, appropriate magnesium supply could increase the expression of NtMGT1 in the root part of tobacco plants, promote the absorption of magnesium ion by the root system, enhance the gene expression of NtMGT2, NtMGT4 and NtMGT5 in shoot part of tobacco plants, promote the transport of magnesium ion, and ensure the normal growth and development of tobacco plants. The results of this study can provide theoretical guidance for reasonable application of magnesium in tobacco production.

关 键 词：烟草 镁营养 镁转运蛋白 MRS2/MGT基因家族 高温强光胁迫 

分 类 号：Q94[生物学—植物学] S572[农业科学—烟草工业]