Utsugi S, Sakamoto W, Murata M, Motoyoshi F
Research Institute for Bioresources, Okayama University, Kurashiki, Japan.
Plant Mol Biol. 1998 Nov 1;38(4):565-76. doi: 10.1023/a:1006072014605.
We have previously identified two cDNAs encoding vegetative storage proteins (VSPs) in Arabidopsis thaliana. Unlike soybean in which VSPs accumulate at high levels in leaves, A. thaliana VSP mRNAs are abundant in flowers. To understand tissue-specific expression and possible roles of VSPs on reproductive organ development, genes corresponding to VSPs (Vsp1 and Vsp2) and their putative promoters were characterized in this study. Genomic sequence analysis revealed that Vsp1 and Vsp2 resemble each other except in their introns, and that these two genes were organized in a tandem array with an interval of 6 kb in a region. The expression patterns of Vsp1 and Vsp2 were examined using transgenic A. thaliana plants carrying a promoter from Vsp1 or Vsp2 fused to a bacterial beta-glucuronidase (GUS) reporter gene. The promoter from Vsp1 expressed its effect in gynoecia, especially in styles, the basal and distal ends of ovaries and in siliques, whereas the promoter from Vsp2 showed its activity in vegetative shoots, petioles, peduncles and receptacles of floral organs. These results suggest that expression of Vsp1 and Vsp2 may be developmentally regulated in A. thaliana. In the transgenic plants, the GUS activity was induced by wounding in an area around the mid-rib of leaves. Therefore, Vsp1 and Vsp2 promoters appear to have elements required for both tissue specificity and wounding.
我们之前在拟南芥中鉴定出了两个编码营养贮藏蛋白（VSPs）的cDNA。与大豆中VSPs在叶片中大量积累不同，拟南芥中的VSP mRNA在花中含量丰富。为了了解VSPs的组织特异性表达及其在生殖器官发育中的可能作用，本研究对与VSPs（Vsp1和Vsp2）相对应的基因及其推定启动子进行了表征。基因组序列分析表明，Vsp1和Vsp2除内含子外彼此相似，且这两个基因在一个区域内以6 kb的间隔呈串联排列。使用携带与细菌β-葡萄糖醛酸酶（GUS）报告基因融合的Vsp1或Vsp2启动子的转基因拟南芥植株，检测了Vsp1和Vsp2的表达模式。Vsp1的启动子在雌蕊中发挥作用，尤其是在花柱、子房的基部和顶端以及角果中，而Vsp2的启动子在花器官的营养枝、叶柄、花柄和花托中显示出活性。这些结果表明，Vsp1和Vsp2的表达在拟南芥中可能受发育调控。在转基因植株中，叶片中脉周围区域的伤口可诱导GUS活性。因此，Vsp1和Vsp2启动子似乎具有组织特异性和伤口诱导所需的元件。
