光敏核不育水稻农垦58S花粉败育过程中Ca^(2+)-ATPase的变化

Changes of Ca^(2+)-ATPase in Photosensitive Genic Male Sterile Rice Nong-ken 58S during Pollen Aborting

运用电镜细胞化学技术(铅盐沉淀法),对长日照条件下光敏核不育水稻农垦58S和可育株系58N花药发育的不同时期进行了Ca2+-ATPase定位研究。结果表明,Ca2+-ATPase颗粒在可育与不育水稻的花药壁、花粉及药隔中的出现时间和数量具有明显差异。可育花药在花粉母细胞时期,药壁细胞内出现Ca2+-ATPase颗粒,至单核花粉后期,解体的绒毡层细胞和乌氏体表面分布大量的Ca2+-ATPase颗粒;与可育材料相比,不育花药在花粉发育的同时期,Ca2+-ATPase颗粒在药壁各层细胞内不仅出现的时间滞后,且分布的数量较少,到二核花粉时期(花粉已畸形空瘪),药壁表皮细胞的液泡膜上、绒毡层细胞质中及乌氏体表面才出现明显的Ca2+-ATPase颗粒。可育花粉单核早期,花粉细胞内线粒体膜上有少量的Ca2+-ATPase分布;单核花粉中期,花粉外壁上有少量的Ca2+-ATPase分布;到单核花粉后期,Ca2+-ATPase颗粒大量分布在花粉外壁、内壁及细胞质膜和细胞核中。而不育花粉在单核花粉发育中都未见Ca2+-ATPase的分布,到花粉败育空瘪时才出现明显的Ca2+-ATPase颗粒,但数量较可育花粉同期同部位少。可育花药药隔细胞中Ca2+-ATPase在花粉母细胞减数分裂期就有分布,而不育花药到单核花粉早期药隔中才有少量的Ca2+-ATPase分布。由此推测,水稻不育系在其花粉发育中,由于细胞壁和质膜上Ca2+-ATPase颗粒出现时间滞后和数量减少影响到细胞膜钙泵将Ca2+由胞质向胞外转运的功能,致使胞质内Ca2+过多积累,导致花粉败育。

TEM and lead nitrate were used to locate Ca^2＋-ATPase in the anther development of photoperiod-sensitive genic male sterile rice Nongken 58S and normal fertile rice Nongken 58N. The results showed that the quantity and the producing time of Ca^2＋-ATPase in the anther wall, connective tissue, and pollen of fertile and sterile rice were markedly different. Some of Ca^2＋-ATPase distributed on the epidermal cells of fertile anther at pollen mother cell stage. And there were some Ca^2＋-ATPase in different anther wall cells, the more on the Ubisch body during the development of the pollen. Comparatively, the less and the late-produced Ca^2＋-ATPase distributed in different anther wall cells of the sterile anther at the same stage. There were visible Ca^2＋-ATPase in the vacuole membrane of epidermal cell, cytoplasm of remained tapetum cell, and the surface of Ubisch bodies at the binucleate pollen stage. Abundant Ca^2＋-ATPase distributed on the exine, the intine, the membrane of cytoplasm, and the nucleus of fertile pollen at the late uninucleate pollen stage, but no Ca^2＋-ATPase distributed on the sterile pollen during the development of the anther except binucleate pollen stage. The quantity of Ca^2＋-ATPase in the sterile pollen was less than that in the fertile pollen at the binucleate pollen stage. There were most Ca^2＋-ATPase in the fertile connective tissue at pollen mother cell meiosis stage. Comparatively, a little Ca^2＋-ATPase distributed in the sterile connective tissue until the pre-uninucleate pollen stage. We suppose that the reason of pollen abortion is the less and later-produced Ca^2＋-ATPase distribution on the sterile pollen wall and the plasma membrane during the sterile anther development. Thus, the Ca^2＋ pump is in low activity to transport Ca^2＋ leading to pollen abortion in sterile lines due to abundant Ca^2＋ in the cytoplasm.