【摘要】 用16%PEG-6000对玉米耐旱自交系“81565”进行模拟干旱处理,用DD-PCR技术研究干旱与正常浇水对照的mRNA差异表达,发现3个干旱条件下差异表达的特异片段MD1、MD2和MD3。MD1和MD2在干旱条件下减量表达,MD3为干旱诱导表达。序列分析和同源性比对表明,MD1与玉米叶绿体基因组中编码参与RNA转录本Ⅱ型内含子剪切的成熟酶的matK基因有93%的相似性,MD2与极端耐旱的Sporobolus stapfianus的丝氨酸/苏氨酸2C型蛋白磷酸酶基因PP2C的相似性达99%,MD3与属天冬氨酸特异性半胱氨酸蛋白酶类的水稻metacaspase基因有99%的相似性。根据各自序列相似同源基因的功能推测,MD1、MD2和MD3三个片段可能与“81565”的耐旱机制有关。更多还原

【Abstract】 16% PEG-6000 was used for simulating drought treatment to drought tolerant maize inbred line ’81565’.DD-PCR technique was used to research mRNA differential expression between drought stress and irrigated control.3 specific fragments: MD1,MD2 and MD3,were found differentially expressed under drought stress.The expression of MD1 and MD2 was down-regulated and the expression of MD3 was induced under drought stress.Sequence analysis and homology alignment showed that MD1 had 93% similarity with matK in maize chloroplast genome,a gene encoding maturase included in typeⅡ intron splicing of RNA transcript;MD2 had 99% similarity with gene PP2C,encoding serine / threonine protein phosphatase type 2C in extremely drought tolerant Sporobolus stapfianus;and MD3 had 99% similarity with rice gene encoding metacaspase,belonging to aspartic acid specific cysteine caspases.It was concluded according to the functions of their homologous sequences that fragments MD1,MD2 and MD3 feasibility related to drought tolerance mechanism of inbred line ’81565’.更多还原