| Tianfeng A,a three-line sterile line of the indica rice,is cultivated by the Guangdong Academy of Agricultural Sciences. Its rice quality is excellent, the disease resistance is strong, the outcrossing is high, and it has strong heterosis and wide adaptability. At present, Tianfeng A has been used to obtain a series of hybrid combinations, but not clearly on its sterility mechanism. The paper takes sterile line Tianfeng A and its maintainer Tianfeng B as experimental materials. By observing its anthers cytological morphology and sub-microstructure showed that the abortion occurred mainly in the late stage of the single nucleus to the second nucleus. And the content of soluble protein, soluble sugar, proline, ATP and ATPase in the anthers were analyzed. Finally,the proteomic differences were analyzed by two-way electrophoresis and mass spectrometry technology. The aim of this study was to analyze the causes of male sterility in rice, and to provide a theoretical basis for revealing the mechanism of cytoplasmic male sterility. The results are as follows:1. Tianfeng A and Tianfeng B anthers in the cytological morphology has significant differences. Tianfeng B has 6 anthers, which were plump and round. But Tianfeng A some anther less than 6, anthers shriveled, pollen grains of different sizes.The results of electron microscopy showed that the number of pollen in the anthers was not enough, and the accumulation of starch and other storage material was lacking in the two nuclear period. Indicating that Tianfeng A anther development is not normal in the two nuclear period.2. The content of soluble protein, soluble sugar content, proline content, ATP and ATPase in Tianfeng A anthers were lower than those in maintainer line Tianfeng B,especially in the two nuclear period. This may be due to insufficient supply of soluble protein and soluble sugar in the single nucleus to the second nucleus and ATP synthase activity decreased. At the same time, lacking of proline in Tianfeng A was not provide important energy and nitrogen source for the pollen germination and pollen tube elongation. It was further confirmed that Tianfeng A pollen abortion was caused by the obstruction of nutrient supply and the lack of energy during pollen development.3. 50 differential protein spots of anther proteomic of the sterile line and maintainer line in two nuclear period was analysised and successfully identified by MALDI-TOF/TOF-MS. According to the putative physiological function, the identified protein were mainly grouped into 8 categories: material metabolism (13),energy metabolism (13), transcription (2), protein synthesis (3), protein storage and localization (3), cell structure (2), defense system (7) and unknown functional protein(7). The up-regulation of proteolytic enzyme expression and the down-regulation of translation elongation factor (EF-1,EF-2)expression resulted that the relevant protein can not be normal synthesis and degradation in Tianfeng A pollen. The low expression of ATP synthase ? subunit in energy metabolism decreased the activity of ATP synthase, resulting in insufficient energy supply. The expression level of the hydrolase involved in the metabolism of amino acids (the effect of the decomposition of proline precursors) was increased. So that proline can not be normal synthesis. The expression of these differential proteins was consistent with the results of the above physiological indexes. In addition, the expression of actin involved in the cytoskeleton was down-regulated which will cause the abnormal development of cell structure.In summary, the male sterile line Tianfeng A pollen abortion mainly occured in the late stage of the single nucleus to the two nuclear period, which may be due to the material and energy-related protein in anthers expression abnormalities. Therefore,pollen abortion is due to anther metabolic disorders, lack of inclusions, lack of energy supply, leading to pollen abortion, eventually leading to male sterility. |
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