Comparative cytological and transcriptomic analysis of pollen development in autotetraploid and diploid rice
Comparative cytological and transcriptomic analysis of pollen development in autotetraploid and diploid rice
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同源四倍体和二倍体水稻花粉发育的比较细胞学和转录组分析
DOI：
10.1007/s00497-014-0250-2
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发表时间：
2014-12-01
影响因子：
3.4
通讯作者：
Lu, Yonggen
中科院分区：
文献类型：
--
作者：
Wu, Jinwen;Shahid, Muhammad Qasim;Lu, Yonggen
同源四倍体水稻比二倍体水稻具有更大的遗传变异和更高的活力，但花粉育性低是造成同源四倍体水稻产量低的主要原因之一。同源四倍体水稻花粉育性低的分子机制目前还知之甚少。本研究利用细胞学观察和基因芯片技术对同源四倍体和二倍体水稻花粉发育过程中的遗传变异进行了研究。在同源四倍体减数分裂过程中发现了许多异常的染色体行为，如多价体、落后染色体、不同步分裂等。同源四倍体水稻的小孢子发生和小配子发生与二倍体水稻相似，但在同源四倍体水稻中发现了许多不同类型的异常现象，包括小孢子退化、多孔和细胞壁异常等。同源四倍体水稻与二倍体水稻相比，花粉转录组中共有1,251个基因差异表达，其中上调基因1,011个，下调基因240个。在花粉发育的3个时期，共表达上调的基因有124个，共表达下调的基因有6个。这些结果表明，在花粉发育过程中，多倍体诱导的大多数基因的上调。根据基因本体分析的结果，从功能分类中筛选出12个差异表达基因，并进行定量RT-PCR验证。这些稳定表达的基因不仅与花粉发育相关，而且还参与细胞代谢、细胞生理、结合、催化活性、分子转导活性和转录调节活性。本研究表明同源四倍体水稻中某些关键基因的差异表达可能导致复杂的基因调控和花粉发育异常。
Autotetraploid rice has greater genetic variation and higher vigor than diploid rice, but low pollen fertility is one of the major reasons for low yield of autotetraploid rice. Very little is known about the molecular mechanisms of low pollen fertility of autotetraploid rice. In this study, cytological observations and microarray analysis were used to assess the genetic variation during pollen development in autotetraploid and diploid rice. Many abnormal chromosome behaviors, such as mutivalents, lagged chromosomes, asynchronous cell division, and so on, were found during meiosis in autotetraploid. Microsporogenesis and microgametogenesis in autotetraploid rice was similar to diploid rice, but many different kinds of abnormalities, including microspores degeneration, multi-aperture, and abnormal cell walls, were found in autotetraploid rice. Compared with diploid rice, a total of 1,251 genes were differentially expressed in autotetraploid rice in pollen transcriptome, among them 1,011 and 240 genes were up-regulated and down-regulated, respectively. 124 and 6 genes were co-up-regulated and co-down-regulated during three pollen development stages, respectively. These results suggest that polyploidy induced up-regulation for most of the genes during pollen development. Quantitative RT-PCR was done to validate 12 differentially expressed genes selected from functional categories based on the gene ontology analysis. These stably expressed genes not only related to the pollen development genes, but also involved in cell metabolism, cell physiology, binding, catalytic activity, molecular transducer activity, and transcription regulator activity. The present study suggests that differential expression of some key genes may lead to complex gene regulation and abnormal pollen development in autotetraploid rice.