毛竹茎秆纤维细胞发育过程中ATP酶的超微细胞化学定位研究

采用磷酸铅沉淀技术,对毛竹茎秆纤维细胞发育过程中的ATP酶进行了超微细胞化学定位研究.在初生壁形成时期,大量的ATP酶的活性产物沉积在质膜、质膜内陷、运输小泡、胞间连丝等膜体系以及细胞核和各种细胞器上;在次生壁形成的初期,ATP酶在多泡小体和裂解的液泡膜上出现,凝聚并边缘化的染色质上仍然具有ATP酶活性;随着次生壁的逐渐加厚,在前四年中持续存在具有ATP酶活性的质膜内陷结构,以后消失;而在六年生纤维细胞的质膜、运输小泡、纹孔、胞间连丝和凝聚化的染色质上仍然发现有明显的ATP酶分布,并发现在染色质上ATP酶活性会随着凝聚程度的加深而增强.结果表明,ATP酶在毛竹茎秆纤维细胞壁的整个形成过程中发挥重要作用,而纤维细胞的次生壁形成过程是一个由核基因控制的主动的PCD过程;并证实毛竹茎秆纤维细胞的发育有别于其它木本植物纤维细胞的发育过程,这种纤维细胞是一种典型的长寿细胞.

Ultracytochemical localization of ATPase during the fiber development in Phyllostachys edulis culm

The ultracytochemical localization during the fiber development in the culm of Phyllostachys edulis (Carr.) H. De Lehaie was studied using a lead phosphate precipitation technique. During the primary wall formation, ATPase deposits were distributed in the membrane systems such as plasmalemma, plasmalemma invagination, transfer vesicles, plasmodesmata, and nucleus and all kinds of organelles. In the early stage of secondary wall formation, the distributions of ATPase appeared in the multivesicular bodies and collapsed tonoplast, but remained in agglutinated chromatin. During the thickening of secondary wall, the plasmalemma invagination with ATPase would persist in the fiber of four-year-old culm, but not in that of six-year-old culm. In one to six-year-old culm, ATPase would visualized in plasmalemma, transfer vesicles, pits, and plasmodesmata and agglutinated chromatin of fiber, but would increased in chromatin with the increase of agglutinated degree. These findings indicated that ATPase played a key role on the cell wall formation of fiber in Phyllostachys edulis culm, and the formation of secondary wall was a typical programmed cell death (PCD), which was an energy dependent active process and was controlled by nuclear genes. In addition, the characteristic distribution of ATPase showed that the culm fiber of Phyllostachys edulis, different from the fibers of other woody plants, was a special long-lived cell.