摘要
玉米突变体male-sterile 20s2(ms20s2)是在玉米自交系KWS49中发现的一个无花粉型雄性不育突变体。与野生型相比,ms20s2突变体花药细小且颜色偏浅,花药内未观察到花粉。扫描电镜观察表明,与野生型相比,9叶期突变体ms20s2的花药中未观察到正在减数分裂的花粉母细胞;抽雄后突变体花药壁外部角质层形成异常,内部未观察到乌式体结构。观察不同发育阶段花药的石蜡切片发现,在S6-S7时期,与野生型相比,ms20s2突变体花药部分中间层和绒毡层细胞发生异常分裂,导致花药壁萎缩,花粉母细胞无法正常进行减数分裂,最终造成花粉母细胞死亡,产生雄性不育表型。遗传分析表明,突变体ms20s2的雄性不育表型受单个隐性核基因控制。利用玉米10K SNP芯片对F2定位群体进行基因型分析,初步将该突变位点定位在玉米2号染色体长臂上6.21 Mb区段内。进一步精细定位将该区间缩小到了590 kb,区间包含一个已知的蛋白编码基因MS32(Zm00001eb106620)。对MS32基因进行测序分析,在突变体MS32基因4号外显子上发现了一段3166 bp的大片段插入,可能影响了MS32蛋白功能,造成ms20s2的花药发育异常和雄性不育的表型。等位测验结果表明,突变体ms20s2是雄性不育基因MS32的新等位突变体。组织表达分析发现该基因在玉米花药中特异表达,且仅在花药发育的S6和S7时期表达量较高,进一步验证了该基因在玉米花药绒毡层和中间层细胞发育过程中的重要作用。
The maize male-sterile 20s2(ms20s2)is a pollen-free genic male sterility mutant that was identified in maize inbred line KWS49.Compared with wild type(WT),the mutant anthers were small and whitish without pollen grains.The scanning electron microscopy(SEM)observations showed that no pollen mother cells undergoing meiosis were observed in the anthers of the ms20s2 at V9 stage.The anther cuticular was abnormal,and failed to generate ubisch bodies on the inner surface of the anther wall of ms20s2 at tasseling stage.By analyzing the paraffin sections of anthers from different developmental stages,some middle layer cells and tapetum cells of the ms20s2 anther underwent abnormal division from S6 to S7 stages compared to WT,leading to the anther wall shrinking,abnormal meiosis and death of the pollen mother cells,and finally male sterility.The segregation analysis in an F2 population revealed that the male sterility of the ms20s2 mutant was controlled by a single recessive nuclear gene.By genotyping with the maize 10K SNP chip,the causal gene was preliminarily mapped to the 6.21 Mb region on the long arm of chromosome 2.The physical interval was further delimited to 590 kb,where a known protein-coding gene MS32(Zm00001eb106620)is present.Sequencing analysis of the MS32 gene revealed a 3166 bp insertion in the exon 4 of ms20s2,and this insertion might result in abnormal anther development and male sterility.Allelism test showed that the ms20s2 was a new allelic variation of maize male sterile gene MS32.The MS32 gene was expressed in maize anthers at S6 and S7 stages,which provided additional evidence in regulating the development of tapetum and middle layer of maize anthers.
作者
周玉强
曹枭雄
王婧
刘伊凡
王红武
李坤
刘小刚
黄长玲
李树强
刘小龙
张亚男
于飞荣
马庆
胡小娇
ZHOU Yuqiang;CAO Xiaoxiong;WANG Jing;LIU Yifan;WANG Hongwu;LI Kun;LIU Xiaogang;HUANG Changling;LI Shuqiang;LIU Xiaolong;ZHANG Yanan;YU Feirong;MA Qing;HU Xiaojiao(School of Life Sciences,Anhui Agricultural University/National Engineering Laboratory of Crop Stress Resistance Breeding,Hefei 230036;Institute of Crop Sciences,Chinese Academy of Agricultural Sciences/National Engineering Research Center of Crop Molecular Breeding,Beijing 100081;Xinjiang Hua Xia Agricultural Co.,Ltd,Urumqi 830000)
出处
《植物遗传资源学报》
CAS
CSCD
北大核心
2024年第2期171-183,共13页
Journal of Plant Genetic Resources
基金
国家重点研发计划(2022YFD1200802)
中国农业科学院科技创新工程项目(CAAS-ZDRW202004)。
