白肋烟是普通烟草（Nicotiana tobacum. L）马里兰烟的缺绿突变类型。本研究在测定比较了白肋烟和马里兰烟叶片叶绿素酶活性的基础上，以18s rRNA为内参基因，采用实时定量PCR技术检测分析了成株期白肋烟和马里兰烟叶片中叶绿素酶基因的表达情况。酶活性测定结果发现白肋烟Burley21和马里兰烟Md609叶片中的叶绿素酶活性分别为525.17 nmol/(g?h)和257.60 nmol/(g?h)，前者为后者的2.03倍。实时定量PCR检测结果表明，Burley21中叶绿素酶基因相对表达量为Md609中的3.01倍。这表明白肋型烟草叶片中叶绿素酶活性及其基因表达量的升高，可能导致了叶绿素的快速降解，从而使白肋烟叶片呈现缺绿黄化性状表现。

Burley tobacco is the cholorophyll deficient mutant of Maryland tobacco. In this study, we analyzed the activities of chlorophyllase between Nicotiana tobacum. L varieties of Burley21 and Md609, and the expression of chlorophyllase gene were further detected using real-time quantitative PCR. The results indicated that the activities of chlorophyllase in Burley21 and Md609 were 31.31 nmol/(g?h) and 15.36 nmol/(g?h), respectively. The relative gene expression of Burley21 was 3.01 as compared to Md609. This indicated that the yellowing leaf phenotype of the Burley tobacco might due to the increased chlorophyllase activity as well as its gene expression.