小麦花药发育过程超微结构和酶细胞化学研究

Ultrastructural and enzyme-cytochemical study on developing wheat anther

通常认为是保护组织的药壁表皮和与花粉囊开裂有关的药室内壁细胞 ,在单核花粉粒到花粉粒成熟前夕一直保持着活跃的生命活动状态。细胞内具丰富活力旺盛的细胞器 ,尤其是粗面内质网和囊泡发达的高尔基体以及胞间连丝 ,细胞核、核仁中的ATP酶活性和线粒体内嵴的细胞色素氧化酶活性达到最强。在二细胞后期 ,药壁表皮细胞内出现球型颗粒积累 ,且随着花粉粒的发育逐渐增多 ,以至当花粉粒被淀粉粒充满时 ,该颗粒剧增 ,相当一部分药壁表皮细胞被球型颗粒充满 ,这时药隔薄壁细胞内也有大量的相同颗粒积累。分析认为药壁表皮细胞内的球型颗粒是来自药隔维管细胞营养物质的积累 ,药壁表皮和药室内壁细胞旺盛的代谢活性可能与绒毡层解体和花粉粒对营养物质的需求相关。从四分体到单核花粉粒时期 ,小孢子的发育主要以细胞质的繁殖和体积的增大为主 ,细胞器数量增加不明显 ,线粒体不发达的内嵴上没有细胞色素氧化酶活性 ,细胞核和核仁中有ATP酶活性。第一次有丝分裂完成后 ,花粉粒内壁开始发生 ,内壁的形成需要能量与质膜参与 ,成熟的内壁中具径向的、膜性结构的管状通道 ,在管状通道和外壁的微通道中有显著的ATP酶活性 ,成熟花粉粒萌发孔区的ATP酶活性更显著。二细胞时期 ,花粉粒细胞质活性发生较大的变化 ,各种细?

Combining the activity of ATPase and cytochrome oxidase with ultrastructural feature,the function of various organizations in wheat anther were analysed by using ultracytochemical localization and electron microscopic techniques. The results showed that there were numerous rough ER, Golgi bodies and plasmodesmata in the epidermis and endothecium cells during mononuclear to tricellular pollen when the activity of ATPase and cytochrome oxidase were the strongest and the metabolism was active. At the late bicellular stage globular grains accumulated in the epidermis. As the growth of pollen, the globular grains continually increased, and when pollen grains were full of starch grains, the globular grains dramatically increased so that some of the epidermis were full of them. Meanwhile, vascular parenchyma were also full of the golobular grains, All these suggested that the globular grains in the epidermis were accumulation of nutritional substance from vascular cells, the active metabolism in the epidermis and endothecium cells were related to disintegration of the tapetum and requirement of pollen for nutritional substance. From tetrad to mononuclear stage, the development of microspore was mainly its volume expansion and increase of cytoplasimic content in which the amount of organelles almost didn't rise and the activity of cytochrome oxidasein on cristal membrane of mitochondria was not observed, ATPase activity appeared in the nucleus and nuclealus. Following the first mitosis pollen the intine deposition began. The deposition of the intine required the participation of energy and plasmic membrane. There were radially oriented tubular channels in the mature intine, obvious ATPase activity was observed in the tubular channels and microchannels of the exine and that around germination aperture was more remarkable .In the bicellular pollen,the cytoplasmic activity rised; the number of every organelle increased at double speed and their function remarkably strengthen ;the energy began self supporting and the metabolism reached a high tide. The activity of cytochrome oxidase appeared in the cristal membrane of mitochondria, and with the pollen development, the activity became stronger. The mature pollens were full of mitochondria with developed cristae where obvious cytochrome oxidase activity was observed.