烤烟烟碱转运蛋白基因与烟碱积累的相关性研究

Study on the Correlation between Nicotine Accumulation and Nicotine Transporter Genes in Flue-cured Tobacco

解析烟碱转运相关基因对烟碱积累的影响,可为定向改良烟碱性状提供理论指导。本研究对7份烟碱含量不同的烤烟进行水培,检测打顶前后烟碱含量、烟碱合成基因(NtPMT、NtQPT)、烟碱转运基因(NtNUP1、NtJAT1/2、NtMATE1/2)以及囊泡运输调节基因(NtGEF)的表达量变化。经相关分析、主成分分析和相关网络分析表明:(1)烟碱合成基因NtPMT、NtQPT与烟碱转运基因NtNUP1、NtMATE1/2相互促进表达;(2)根部和叶部的主效烟碱转运基因中,NtJAT1是腰叶的主要烟碱转运基因,NtNUP1、NtJAT1、NtMATE1/2在根部对烟碱转运都有贡献,且转运效率依次递减;(3)囊泡运输调节因子NtGEF也能间接影响叶部烟碱积累。因此,在对烟碱性状进行定向改良时,可考虑烟碱合成、转运以及囊泡运输调节因子对烟碱积累的贡献大小。

In order to provide theoretical guidance for high quality tobacco breeding,analysis of contribution from nicotine transport related factors to nicotine accumulation was conducted.Seven flue-cured tobacco germplasms with different nicotine contents were planted in hydroponics devices and were treated by topping.The nicotine content,and expression levels of 2 key nicotine biosynthetic genes(NtPMT,NtQPT)and 3 transporters genes(NtNUP1,NtMATE1/2,NtJAT1/2)and a vesicular traffic regulator gene(NtGEF)were detected and analyzed.Correlation analysis,principal component analysis and related network analysis were conducted.The results showed that:(1)expression of nicotinic biosynthetic genes(NtPMT and NtQPT)and nicotine transporter genes(NtNUP1 and NtMATE1/2)was promoted by each other;(2)nicotine transporter genes that play dominant roles in leaves and roots were different.NtJAT1 was the dominant transporter in middle leaves;NtNUP1,NtJAT1 and NtMATE1/2 genes were the main genes of nicotine transportation in the root,with their transporting efficiency decreased in the above listed order;(3)the vesicular traffic regulator gene(NtGEF)also indirectly affected the accumulation of nicotine in middle leaves.Therefore,when seeking directional improvement for nicotine content,breeders should consider the influence of nicotine synthesis genes,transporter genes and vesicle transport regulatory factors on nicotine accumulation.