玉米（Zea mays L.）过氧化物酶编码基因px和冷调控蛋白编码基因cld的物理定位

过氧化物酶是植物抗病过程中的关键酶，也参与植物抗低温胁迫以及一些正常的植物生长发育生理过程。冷调控蛋白是植物抗低、高温的重要蛋白。近年的研究表明植物抗病、某些正常生长发育过程。冷调控蛋白是植物细胞程序性死亡有关。以玉米自效系黄早四为材料，采用生物素标记，利用原位杂效技术绎玉米中过氧化物酶和冷调控蛋白编码基因ｐｘ与ｃｌｄ进行了原位杂效定位，ＤＡＢ和荧光检测得到了一致的结果。在２号和７号染色体长臂同时

Physical Mapping of the Genes px and cld Coding Peroxidase and Cold-regulated Protein in Maize (Zea mays L.)

Peroxidase plays a key role in plant disease resistance, cold stress and some developmental processes, and cold-regulated protein functions necessarily in reaction of plants on cold or heat stress. Recent studies showed that these processes in plant cells were involved in programmed cell death (PCD). Using a biotin-labelledin situ hybridization (ISH) technique, we physically mapped the genes px and cld coding peroxidase and cold-regulated protein respectively onto maize chromosomes. Both DAB and fluorescence detection systems gave the identical results, the probe uaz235 corresponding to gene px was localized onto the long arm of chromosome 2 (2L) and 7L, and csu19 corresponding to gene cld was hybridized onto 4L and 5L. The percentage distances (from the hybridization sites to centromeres) of uaz235 in 2Land 7L were 45.4±1.3 and 67.4±3.7 respectively, and those of csu19 in 4L and 5Lwere 68.6±2.6 and 58.2±1.6 respectively. The physical positions of px in 2L and cld in 4L coincide with those in their genetic map pattern. The results also show that both of these genes have duplicated sites in maize genome.