High Temperatures Cause Male Sterility in Rice Plants with Transcriptional Alterations During Pollen Development
High Temperatures Cause Male Sterility in Rice Plants with Transcriptional Alterations During Pollen Development
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DOI：
10.1093/pcp/pcp135
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发表时间：
2009-11-01
影响因子：
4.9
通讯作者：
Kawagishi-Kobayashi, Makiko
中科院分区：
文献类型：
--
作者：
Endo, Makoto;Tsuchiya, Tohru;Kawagishi-Kobayashi, Makiko
植物雄性生殖发育是高度组织化的，对包括高温在内的各种环境胁迫非常敏感。我们建立了一个实验程序，以评估高温伤害粳稻植株。在我们的系统中，从小孢子阶段开始的高温处理（39 C/30 C）反复降低小穗育性。形态学观察表明，高温处理的植株花粉生活力低于对照植株。高温处理植株的花粉粒大多呈正常圆形，Alexanders染色呈红紫色，但花粉粒在柱头上的附着力很差，萌发能力有限。为了研究高温环境下花药中的基因调控机制，通过比较未经处理的样品和经24 d高温处理的样品进行DNA微阵列分析。从微阵列数据的聚类中鉴定出对高温有反应的基因。其中，至少有13个被指定为高温抑制基因在花药中。表达分析表明，这些基因在小孢子期的未成熟花药中特异表达，主要在绒毡层中表达，高温处理1d后表达下调。绒毡层特异性基因Osc 6、OsRAFTIN和TDR的表达水平不受高温影响。这些结果表明，并非所有的绒毡层基因被抑制的温度升高和绒毡层本身并没有在这样的环境中降解。然而，高温可能会破坏花粉在柱头上粘附和萌发所需的绒毡层功能。
Plant male reproductive development is highly organized and sensitive to various environmental stressors, including high temperature. We have established an experimental procedure to evaluate high temperature injury in japonica rice plants. High temperature treatment (39C/30C) starting at the microspore stage repeatedly reduced spikelet fertility in our system. Morphological observations revealed that pollen viability in plants exposed to high temperatures was lower than that in control plants. Most pollen grains in high temperature-treated plants displayed a normal round shape and stained reddish purple with Alexanders reagent; however, the pollen grains were very poorly attached and displayed limited germination on the stigma. To investigate gene regulatory mechanisms in the anther in high temperature environments, DNA microarray analysis was performed by comparing non-treated samples with samples treated with 24d of high heat. Genes responsive to high temperatures were identified from clustering of microarray data. Among these, at least 13 were designated as high temperature-repressed genes in the anther. Expression analyses revealed that these genes were expressed specifically in the immature anther mainly in the tapetum at the microspore stage and down-regulated after 1d of high temperature. The expression levels of Osc6, OsRAFTIN and TDR, which are tapetum-specific genes, were unaffected by high temperatures. These results suggest that not all tapetal genes are inhibited by increased temperatures and the tapetum itself is not degraded in such an environment. However, high temperatures may disrupt some of the tapetum functions required for pollen adhesion and germination on the stigma.