Cytological and transcriptome analyses reveal abrupt gene expression for meiosis and saccharide metabolisms that associated with pollen abortion in autotetraploid rice
Cytological and transcriptome analyses reveal abrupt gene expression for meiosis and saccharide metabolisms that associated with pollen abortion in autotetraploid rice
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细胞学和转录组分析揭示了与同源四倍体水稻花粉败育相关的减数分裂和糖代谢基因的突然表达
DOI：
10.1007/s00438-018-1471-0
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发表时间：
2018-12-01
影响因子：
3.1
通讯作者：
Liu, Xiangdong
中科院分区：
文献类型：
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作者：
Chen, Lin;Shahid, Muhammad Qasim;Liu, Xiangdong
同源四倍体水稻是一种有用的种质，具有四个染色体组，具有很强的生物学优势；然而，低生育率限制了其商业利用。关于同源四倍体水稻低育性相关的 DNA 变异和差异基因表达的信息很少。在本研究中，通过全基因组重测序，与 E249（二倍体对应物）相比，T449（低育性同源四倍体水稻品系）中鉴定出了 81 个 SNP 和 182 个 InDels。我们仅检测到 3 个非同义 SNP 和 6 个大效应 InDels，它们分别与 3 个和 6 个基因相关。通过转录组分析，在减数分裂阶段共检测到75个与减数分裂相关的差异表达基因，包括减数分裂DSB形成所必需的OsMTOPVIB和参与同源染色体配对和联会的OsMOF。 T449 中观察到大约 20.69% 的中期 I 滞后染色体和 4.65% 的异常四分体。此外，转录组分析显示T449中单小孢子阶段的一个蔗糖转运蛋白（OsSUT5）和两个单糖转运蛋白（OsMST1和OsMST8）下调，并通过qRT-PCR验证了它们的表达水平。细胞学观察糖类分布发现，T449糖类积累异常，单小孢子期T449果糖和葡萄糖含量明显高于E249。我们的研究结果表明，多倍体不仅引起减数分裂相关基因的表达突变，导致染色体行为异常，而且引起糖类分布和糖类相关基因表达模式的变化，共同导致同源四倍体水稻的不育。
Autotetraploid rice is a useful germplasm that has four chromosome sets and strong biological advantages; however, low fertility limits its commercial utilization. Little information is available about the DNA variation and differential gene expressions associated with low fertility in autotetraploid rice. In the present study, 81 SNPs and 182 InDels were identified in T449 (an autotetraploid rice line with low fertility) compared to E249 (diploid counterpart) by whole-genome re-sequencing. We detected only three non-synonymous SNPs and six large-effect InDels, which were associated with three and six genes, respectively. A total of 75 meiosis-related differentially expressed genes were detected during the meiosis stage by transcriptome analysis, includingOsMTOPVIB, which is essential for meiotic DSB formation, andOsMOF, which takes part in homologous chromosome pairing and synapsis. Approximately 20.69% lagging chromosome at metaphase I and 4.65% abnormal tetrad were observed in T449. Moreover, transcriptome analysis revealed down-regulation of a sucrose transporter (OsSUT5) and two monosaccharide transporters (OsMST1andOsMST8) in T449 at the single microspore stage, and their expression levels were verified by qRT-PCR. Cytological observation of saccharide distribution showed abnormal accumulation of saccharides in T449 and the contents of fructose and glucose were markedly higher in T449 than E249 at the single microspore stage. Our results suggested that polyploidy not only induces abrupt expression changes in the meiosis-related genes that lead to abnormal chromosome behavior, but also causes changes in the saccharide distribution and expression patterns of saccharide-related genes, which jointly causes sterility in the autotetraploid rice.