The Oryza sativa no pollen (Osnop) gene plays a role in male gametophyte development and most likely encodes a C2-GRAM domain-containing protein
The Oryza sativa no pollen (Osnop) gene plays a role in male gametophyte development and most likely encodes a C2-GRAM domain-containing protein
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DOI：
10.1007/s11103-005-2859-x
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发表时间：
2005-04-01
影响因子：
5.1
通讯作者：
Ramachandran, S
中科院分区：
文献类型：
--
作者：
Jiang, S;Cai, M;Ramachandran, S
通过Ds插入系的表型筛选，鉴定出一个雄性不育的无花粉水稻（Orysa sativa no pollen, Osnop）突变体，该突变体在花期具有无花粉表型。突变体表型与Ds插入Osnop基因区有关。该突变体在Ds插入位点缺失了65kb的染色体区域，其中包含14个预测基因。在这些缺失的基因中，deleen 5- 7,9 -10是冗余的，因为在水稻基因组的其他区域存在2或3个拷贝，同源性为100%。RT-PCR分析表明，deleen 5-7不仅在野生型植株中表达，也在突变植株中表达。此外，在正常生长条件下无法检测到Delegen 8-10的转录本，而Delegen 12仅在根中表达，因此这些基因的缺失可能不会影响花粉的发育。我们的数据和分析也排除了委派1- 4,11和13作为促成无花粉表型的候选基因的可能性。通过RT-PCR、Northern blotting、原位杂交和启动子- gus转基因植株的进一步研究表明，该基因仅在花粉发育后期表达，在花粉释放和萌发阶段表达量最高。因此，delegen 14基因是Osnop的最佳候选基因，对应于突变体的无花粉表型。结果表明，代子14可能在花粉发育后期和萌发过程中起重要作用。由于delegen 14基因同时具有C-2和GRAM结构域，因此可以假设该基因交联钙和磷酸肌苷信号通路。这是首次报道该基因在植物发育中的可能功能。
Phenotype screens of Ds insertional lines identified a male sterile Orysa sativa no pollen (Osnop) mutant with a pollen-less phenotype at the flowering stage. The mutant phenotype showed linkage to Ds insertion into Osnop gene region. This mutant contained a deletion of 65 kb chromosomal region at the site of Ds insertion containing 14 predicted genes. Out of these deleted genes, Delegen 5-7, 9-10 were redundant, as two or three copies were present with 100% homology in other regions of rice genome. RT-PCR analysis showed that Delegen 5-7 were expressed not only in wild type plants but also in the mutant plants. In addition to this, Delegen 8-10 transcripts could not be detected under normal growth conditions, and Delegen 12 was expressed only in roots, thus deletion of these genes may not affect the pollen development. Our data and analysis also ruled out the possibility of delegen 1-4, 11, and 13 as candidates contributing to the pollen-less phenotype. Further investigation showed that the delegen 14 was expressed only in late stage of pollen development with the highest expression at the stage of pollen release and germination by RT-PCR, Northern blotting, in situ hybridization, and promoter-GUS transgenic plants. Thus, the delegen 14 gene is the best candidate for Osnop, corresponding to the pollen-less phenotype in the mutant. Our data suggest that delegen 14 may play an important role during late stage of pollen development and its germination. Since the delegen 14 gene has both C-2 and GRAM domains, it can be assumed that this gene cross-links both calcium and phosphoinositide signaling pathways. This is the first report to suggest possible functions for this gene in plant development.