摘要
【目的】D2型细胞质是细胞质雄性不育小麦(cytoplasmic male sterility,CMS)的重要胞质来源,深入研究其败育机理对小麦杂种优势利用具有重要价值。【方法】以3种同核异质D2型细胞质雄性不育小麦Va87B1-706A、C687B1-706A、Ju87B1-706A及其相应保持系706B为试材,通过体式显微镜和DAPI染色分别在四分体时期、单核早期、单核晚期、二核期和三核期观察小麦花药的外形和小孢子发育的形态;利用扫描电镜和KI-I2染色分析三核期花药外皮层、内皮层、乌氏体和花粉粒的表型及败育特点;采用石蜡切片和DNA ladder的技术观察不同发育时期D2型不育系和保持系小麦花药绒毡层细胞形态变化特征以及绒毡层细胞程序化死亡(programmed cell death,PCD)的过程;测定花药发育过程中活性氧(reactive oxygen species,ROS)的含量,超氧化物歧化酶(superoxide dismutase,SOD)、过氧化物酶(peroxidase,POD)、过氧化氢酶(hydrogen peroxidase,CAT)、抗坏血酸过氧化物酶(ascorbate peroxidase,APX)和谷胱甘肽过氧化物酶(glutathione peroxidase,GPX)的活性以及非酶物质还原型抗坏血酸(ascorbic acid,AsA)和谷胱甘肽(glutathione,GSH)的含量变化;同时利用RT-PCR技术对部分抗氧化酶相关基因的表达模式进行分析。【结果】与保持系706B比较,3种D2型细胞质雄性不育小麦在三核期均表现出外皮层表皮褶皱、乌氏体排列稀疏散乱以及小孢子皱缩、表皮粗糙和萌发孔闭合的不育特征,败育类型为典败和染败;自单核晚期开始3种不育小麦的小孢子发生紊乱;石蜡切片观察绒毡层细胞的变化,发现不育系均比保持系延迟一个时期在二核期发生解体,并于三核期完全降解;进一步检测细胞凋亡DNA小片段发现3种不育系花药绒毡层的DNA损伤均起始于单核晚期,绒毡层PCD比保持系延迟一个时期启动,并且优先细胞学表型检测到凋亡;生理指标测定和定量分析的结果说明绒毡层�
【Objective】D^2 type cytoplasm is the considerable source of cytoplasm of cytoplasmic male sterility（CMS）.It is of great value to further study the cytological characteristics and mechanism of physiology and molecules in heterologous cytoplasmic male sterility（CMS） wheat for the heterosis utilization.【Method】To elucidate the abortive cytological characteristics of D^2-type cytoplasmic male-sterility,the phenotypes of anthers,microspores,tapetum were analyzed by scanning electron microscope,DAPI staining,and paraffin section,as well as detecting tapetal apoptotic DNA fragmentation by DNA ladder.To further clarify that the D^2-type cytoplasmic male-sterility is associated with abnormal tapetal programmed cell death and reactive oxygen species metabolism,the physiological properties,including the contents of reactive oxygen species（ROS）,activities of ROS-scavenging enzymes（superoxide dismutase（SOD）,peroxidase,catalase（CAT）,ascorbate peroxidase（APX）,and glutathione peroxidase（GPX）） and nonenzymatic antioxidants（ascorbic acid（AsA） and glutathione（GSH））,and the expression levels of antioxidant-associated genes from three D^2-types of cytoplasmic male sterile lines（Va87 B1-706 A,C687 B1-706 A,Ju87 B1-706 A） and the maintainer 706 B of wheat were compared.【Result】Compared with the maintainer line,at the trinucleate stage,the inner epidermal cells of D^2-type cytoplasmic male-sterility accumulated less and more unconsolidated Ubisch bodies and the epidermis of microspores were extremely scabrous.The abortive pivotal period of pollen was initiated at the later uninucleate stage,which the delayed degradation of tapetum and abnormal structure of the microspore were related to the serious oxidative stress,disorganized activities of antioxidant enzymes,down-regulated contents of non-enzymatic antioxidants and significant difference of the expression level of some related enzyme genes in the three D^2-types of cytoplasmic male sterile lines.Additionally,the expression l
出处
《中国农业科学》
CAS
CSCD
北大核心
2017年第21期4071-4086,共16页
Scientia Agricultura Sinica
基金
国家自然科学基金(31271792)
关键词
小麦
D2型细胞质雄性不育
绒毡层细胞程序化死亡
活性氧代谢
基因表达
wheat （Triticum aestivum L.）
D2-types cytoplasmic male sterility
tapetal programmed cell death
ROSmetabolism
gene expression
