摘要
【目的】为明确烤烟上部叶脂质代谢对烟叶褐变的影响。【方法】以云烟87和中川208两个品种的上部叶为试验材料,利用转录组学、透射电镜、扫描电镜和荧光实时定量PCR(qRT-PCR)技术从细胞生物学和分子层面对脂质氧化与上部烟叶的褐变关系进行系统的研究。【结果】(1)相比云烟87,易褐变的中川208上部叶褐变速度更快,且叶片达五成的褐变时间更短,褐变反应更剧烈;进一步的转录组GO分析和KEGG富集分析结果显示中川208上部叶差异基因在脂类代谢(亚麻酸和亚油酸代谢)富集较多,表明脂质代谢与上部叶烟叶褐变密切相关。(2)对比云烟87,中川208上部叶成熟期角质层厚度明显增加,蜡质层破碎薄片明显增多,总脂肪酸含量、亚麻酸含量及脂氧合酶(LOX)酶活显著高于云烟87,表明中川208上部叶脂类代谢较旺盛,易发生脂质氧化。(3)qRT-PCR结果表明中川208上部叶中脂类代谢途径关键基因CYP76A2、LOX5、LTP4、MYB108、ALDH2B7等的表达量显著高于云烟87,其中脂质氧化关键基因LOX5表达量上调2.27倍。【结论】相比云烟87上部烟叶,中川208上部叶褐变反应更剧烈,烟叶中的脂肪酸代谢更旺盛,脂类物质更易发生氧化反应,表明脂肪酸代谢引起的脂质氧化是中川208上部烟叶易褐变的一个重要因素。
[Background and Objective]This study aims to clarify the effects of lipid metabolism in upper leaves of flue-cured tobacco on leaf browning.[Methods]In this study,the relationship between lipid oxidation and Browning of the upper leaves of Yunyan 87 and Zhongchuan 208 were systematically studied by means of transcriptomics,transmission electron microscopy,scanning electron microscopy and real-time quantitative PCR(RT-PCR)in cell biology and molecular level.[Results](1)Compared with Yunyan 87 tobacco leaves,Zhongchuan 208 tobacco leaves were browning faster,and the time for leaves to become 50%brown was shorter,and the browning reaction was more intense;Further transcriptomic GO analysis and KEGG enrichment analysis showed that the differential genes in the upper leaves of Zhongchuan 208 were enriched in lipid metabolism(linolenic acid and linoleic acid metabolism),suggesting that lipid metabolism was closely related to the browning of the upper leaves.(2)The cuticle was significantly thickened,the broken wax layer and thin slices were obviously increased in Zhongchuan 208 tobacco leaves.The total fatty acid content,linolenic acid content,and lipoxygenase(LOX)enzyme activity were significantly higher than those of the control,indicating that the lipid metabolism of easy-browning tobacco leaves is relatively vigorous and lipid oxidation is prone to occur.(3)The lipid metabolism genes CYP76A2,LOX5,LTP4,MYB108,ALDH2B7were screened out from the obtained differentially expressed genes,the expression of which were up-regulated in Zhongchuan 208 tobacco leaves according to qRT-PCR analysis.Among them,the expression of NtLOX5,a key gene of lipid oxidation,was up-regulated by 2.27 times.[Conclusion]Compared with the upper leaves of Yunyan 87,the browning reaction of the upper leaves of Zhongchuan 208 is more intense,and the fatty acid metabolism in the tobacco leaves is more vigorous and the lipids are more susceptible to oxidation reactions.The results indicate that lipid oxidation caused by fatty acid metabolism is an important factor for the browning of Zhongchuan 208 tobacco leaves.
作者
孙皓月
李文刚
俞世康
伍德洋
陈汉发
杨洁
宋朝鹏
贾宏昉
谢良文
SUN Haoyue;LI Wengang;YU Shikang;WU Deyang;CHEN Hanfa;YANG Jie;SONG Zhaopeng;JIA Hongfang;XIELiangwen(College of Tobacco,Henan Agricultural University,Zhengzhou 450000,China;Sichuan Tobacco Company,Chengdu 610000,China;Guangyuan Tobacco Company of Sichuan Province,Guangyuan 628000,Sichuan,China;Liangshan Tobacco Company of Sichuan Province,Xichang 615000,China)
出处
《中国烟草学报》
CAS
CSCD
北大核心
2022年第4期31-38,共8页
Acta Tabacaria Sinica
基金
四川省烟草公司科技重点项目“提升上部叶烘烤质量的关键技术研究与应用”(NO:SCYC202116)。
关键词
上部叶
脂质代谢
褐变
转录组学
upper tobacco leaves
lipid metabolism
browning
transcriptomics
