玉米葡萄糖苷酶新突变类型的发现及其基因的分子鉴定

Discovery and Molecular Identification of a New Mutant of Maize β-Glucosidase

寻找并鉴定玉米葡萄糖苷酶2(Glu2)新的突变类型。以单粒玉米自交系种子发芽5￣15d的幼苗为试材,提取葡萄糖苷酶进行电泳检测,对所发现的新的异型材料,提取正在表达高峰时期的RNA,并对其进行逆转录、克隆和测序。测序结果与发表过的Glu2的DNA序列相比较,发现有99.58%是相同的。将其翻译成氨基酸序列相比较,有99.64%是相同的。只不过是在第58个氨基酸由谷氨酰胺突变成谷氨酸;第212个氨基酸由谷氨酰胺突变成组氨酸。DNA序列分析是区别不同遗传性状以及新突变类型的根本方法,再加上氨基酸序列分析就能更进一步解释了造成遗传性状差异的根本原因。为深入研究性状变异和有目的的改良性状,起到积极的指导作用。

The objective of this study was to find and identify the new allozyme of Glu2. The extraction and electroghoresis of β- Glucosidase from 5-15 days＇ corn inbreed line seedlings was made to find different mutants, identify the mutant through separating RNA and RT-PCR as well as cloning procedure. There are 99.58% of Glu2 DNA sequences and 99.64% of Glu2 amino acid sequences identity between the new alloyme and the normal Glu2. The 58th amino acid changes from gluamine to glutamic, the 212th from gluamine to histidine on Glu2 enzyme amino acid sequence. DNA sequencing is the main method to distinguish and explain the genetic characters and mutants.