Impact of Alleles at the Yellow Burley (Yb) Loci and Nitrogen Fertilization Rate on Nitrogen Utilization Efficiency and Tobacco-Specific Nitrosamine (TSNA) Formation in Air-Cured Tobacco

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• 作者：Ramsey S. Lewis ; Robert G. Parker ; David A. Danehower ; Karen Andres ; Anne M. Jack ; D. Scott Whitley ; Lowell P. Bush
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2012
• 出版时间：June 27, 2012
• 年：2012
• 卷：60
• 期：25
• 页码：6454-6461
• 全文大小：451K
• 年卷期：v.60,no.25(June 27, 2012)
• ISSN：1520-5118

文摘

Tobacco-specific nitrosamine (TSNA) formation in tobacco is influenced by alkaloid levels and the availability of nitrosating agents. Tobacco types differ in their potential for TSNA accumulation due to genetic, agronomic, and curing factors. Highest TSNA concentrations are typically measured in burley tobaccos. One of the main genetic differences between burley and all other tobacco types is that this tobacco type is homozygous for recessive mutant alleles at the Yellow Burley 1 (Yb₁) and Yellow Burley 2 (Yb₂) loci. In addition, burley tobacco is typically fertilized at higher nitrogen (N) rates than most other tobacco types. This study utilized nearly isogenic lines (NILs) differing for the presence of dominant or recessive alleles at the Yb₁ and Yb₂ loci to investigate the potential influence of genes at these loci on TSNA accumulation. Three pairs of NILs were evaluated at three different nitrogen fertilization rates for alkaloid levels, nitrogen physiology measures, and TSNA accumulation after air-curing. As previously observed by others, positive correlations were observed between N application rates and TSNA accumulation. Recessive alleles at Yb₁ and Yb₂ were associated with increased alkaloid levels, reduced nitrogen use efficiency, reduced nitrogen utilization efficiency, and increased leaf nitrate nitrogen (NO₃-N). Acting together, these factors contributed to significantly greater TSNA levels in genotypes possessing the recessive alleles at these two loci relative to those carrying the dominant alleles. The chlorophyll-deficient phenotype conferred by the recessive yb₁ and yb₂ alleles probably contributes in a substantial way to increase available NO₃-N during curing and, consequently, increased potential for TSNA formation.

Keywords:

p://pubs.acs.org/action/doSearch?action=search&searchText=tobacco&qsSearchArea=searchText">tobacco; p://pubs.acs.org/action/doSearch?action=search&searchText=tobacco%5C-specific+nitrosamines+%5C%28TSNA%5C%29&qsSearchArea=searchText">tobacco-specific nitrosamines (TSNA); p://pubs.acs.org/action/doSearch?action=search&searchText=nitrogen+utilization+efficiency&qsSearchArea=searchText">nitrogen utilization efficiency; p://pubs.acs.org/action/doSearch?action=search&searchText=nitrosating+agents&qsSearchArea=searchText">nitrosating agents