Anther-specific genes, which expressed through microsporogenesis, are temporally and spatially regulated in model legume, Lotus japonicus
Anther-specific genes, which expressed through microsporogenesis, are temporally and spatially regulated in model legume, Lotus japonicus
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DOI：
10.1266/ggs.81.57
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发表时间：
2006-02-01
影响因子：
1.1
通讯作者：
Watanabe, Masao
中科院分区：
文献类型：
--
作者：
Masuko, Hiromi;Endo, Makoto;Watanabe, Masao
花粉萌发和花粉管伸长是高等植物授粉和受精的重要过程。到目前为止，已经分离和鉴定了几个花粉特异性基因。然而，关于高等植物花粉特异性基因的精确时空表达模式的信息很少。在我们之前的研究中，我们通过cDNA微阵列分析在模式豆科植物百脉根中鉴定了132个花药特异性基因，尽管它们在花药组织中的精确表达位点尚未确定。本研究利用原位杂交技术，对46个花药特异表达基因（约100个）的时空表达位点进行了分析。35%），根据花的发育阶段分为I-a群和II-a群。在将基因分组为簇I-a的情况下，表征了13个克隆。不同无性系间特异性杂交信号不同，在花药组织发育早期的绒毡层细胞、小孢子和花药壁中均观察到特异性杂交信号。在分类为簇II-a的基因的情况下，我们使用了编码初级和次级代谢相关蛋白、细胞壁重建相关蛋白、肌动蛋白重组相关蛋白和糖转运相关蛋白等的33个不同的cDNA克隆，为探针有趣的是，在这33个克隆中检测的所有基因都在双细胞花粉粒中特异性表达，尽管信号强度在克隆之间是不同的。从聚类II-a基因的数据来看，与花粉萌发和花粉管伸长相关的mRNA在成熟花粉粒中特异性转录并保存。
Pollen germination and pollen tube elongation are important for pollination and fertilization in higher plants. To date, several pollen-specific genes have been isolated and characterized. However, there is little information about the precise spatial and temporal expression pattern of pollen-specific genes in higher plants. In our previous study, we identified 132 anther-specific genes in the model legume Lotus japonicus by using cDNA microarray analysis, though their precise expression sites in the anther tissues were not determined. In this study, by using in situ hybridization experiments, we determined the spatial and temporal expression sites of 46 anther-specific genes (ca. 35%), which were derived from two groups, cluster I-a and cluster II-a, according to flower developmental stages. In the case of the genes grouped into cluster I-a, thirteen clones were characterized. The specific hybridized signals were varied among the clones, and were observed in tapetum cells, microspores, and anther walls at the early developmental stage of anther tissues. In the case of the genes classified into cluster II-a, we used thirty three different cDNA clones encoding primary and secondary metabolism-related proteins, cell wall reconstruction-related proteins, actin reorganization-related proteins, and sugar transport-related proteins, etc., as a probe. Interestingly, all genes in these thirty three clones examined were specifically expressed in the bicellular pollen grains, though the signal intensity was varied among clones. From the data of the cluster II-a genes, the mRNAs related to pollen germination and pollen tube elongation were specifically transcribed and preserved in mature pollen grains.