Key Laboratory of MOE for Plant Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Protoplasma. 2010 May;241(1-4):37-49. doi: 10.1007/s00709-009-0100-5. Epub 2010 Feb 6.
To gain further insight into the abortive stages and ultrastructural changes leading to pollen degeneration of a novel cytoplasmic male sterile radish 805A, we compared differences of cellular and subcellular structure of sterile anther with fertile anther by light and electron microscopy analysis. Two types of locule degeneration in sterile anther were detected, of which the time of degeneration occurred and completed was different. In type I, abnormality of pollen mother cells (PMCs) and tapetal cells, including condensation of cytoplasm and large vacuoles within tapetal cells, was shown at PMC stage. In type II, meiosis and early tetrad stage progressed normally except for large vacuoles that appeared in tapetal cells. Ultrastructural alterations of the cellular organization were observed in the type II locules, such as chromatin condensation at the periphery of the nucleus and degeneration of the karyotheca, compared with normal pollen development. The results suggested that the cytoplasmic male sterility anther degeneration was probably caused by dysfunctions of tapetum and vacuolation of tapetum, PMCs, and microspores. Thus, the identical factors, which induced CMS in the same cytoplasmic and nuclear genetic background, might affect development of tapetum and microspore at different stages during the cytoplasmic male sterile 805A anther development.
为了更深入地了解新型细胞质雄性不育萝卜 805A 的败育阶段和导致花粉退化的超微结构变化，我们通过光镜和电镜分析比较了不育花药和可育花药的细胞和亚细胞结构差异。在不育花药中检测到两种类型的小室退化，其中退化发生和完成的时间不同。在 I 型中，花粉母细胞（PMC）和绒毡层细胞的异常，包括细胞质的浓缩和绒毡层细胞内的大液泡，在 PMC 阶段就表现出来。在 II 型中，减数分裂和早期四分体阶段正常进行，除了绒毡层细胞中出现大液泡。与正常花粉发育相比，在 II 型小室中观察到细胞组织的超微结构改变，如核周边染色质浓缩和核仁退化。结果表明，细胞质雄性不育花药退化可能是绒毡层功能障碍和绒毡层、PMC 和小孢子液泡化引起的。因此，在同一细胞质和核遗传背景下诱导 CMS 的相同因素，可能会在细胞质雄性不育 805A 花药发育的不同阶段影响绒毡层和小孢子的发育。
