WD40重复蛋白家族基因Atlg65030调控拟南芥种子的重量与体积

植物中WD40-repeat蛋白在细胞周期调控等方面具有重要作用。本研究鉴定了一株拟南芥WD40-repeat蛋白基因突变体atlg65030。与野生型植株相比种子重量增重体积变大，营养生长长势较弱，角果种子结实率较低。以突变体作为母本／父本与野生型父本／．母本杂交，前者杂交后代未显示有母本的突变表型，后者部分杂交后代显示出父本的突变表型，统计突变体后代分离比符合l：1。用苯胺兰（DAB）、4,6．二氨基．2．苯基吲哚（DAPI）、2,3，5．氯化三苯基四氮唑（TTc）、碘．碘化钾花粉染色，发现花粉部分败育且主要为核败育。爱氏苏木精花粉染色结果显示可观察到正常减数分裂各时期形态。采取热不对称交错PCR（thermal asymmetric interlaced PCR，TAIL—PcR）方法确认突变基因位于第一条染色体65030位置，生物信息学分析表明该基因含有DWD基序。半定量RT-PCR分析发现在拟南芥发育晚期该基因在花器官中大量表达，过表达该基因使种子重量减轻。推测Atlg65030影响了拟南芥花粉发育细胞核有丝分裂过程，该研究增加了人们对调控拟南芥花粉发育分子机制的认识。

Atlg65030, a WD40-Repeat Protein Gene, Regulates Seed Mass and Size in Arabidopsis

WD-repeat proteins play important roles in cell circle regulation and so on in plants. In this study, a novel mutant of WD40-repeat protein gene causing heavier weight and larger size was identified, along with weaker vegetative growth, as well as less seeds yield. We generated seeds with atlg65030 mutant as maternal by crossing wild type as paternal, and vice versa. The atlg65030 mutant could not be obtained by former hy- bridization while the mutant could be obtained by latter test partially. The segregation ratio of Tj and T2 mutant did not comply with typical mendelian inheritance, which indicated the male gamete aborted partially. To fur- ther investigate the mechanism, DAB, DAPI, TTC, 1（1-12 and Ehrlich＇s hematoxylin were employed to stain the pollen, respectively. DAPI staining suggested abnormity in nucleus while modality of meiosis in each period was normal. TAIL-PCR revealed its location on the first chromosome 65 030 of Arabidopsis. Bioinformatics analysis indicated Atlg65030 contained a highly conserved DWD motif. Semi-quantitative RT-PCR analysis showed that Atlg65030 expressed preferentially in the floral during the late development period. Over expres- sion of Atlg65030 caused phenotype of reduced seed weight. The results indicated Atlg65030 played an impor- tant part during the mitosis process of pollen nucleus, which is helpful for understanding the regulation of mo- lecular mechanism regarding the pollen development in Arabidopsis.