Terryn N, Arias M B, Engler G, Tiré C, Villarroel R, Van Montagu M, Inzé D
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Plant Cell. 1993 Dec;5(12):1761-9. doi: 10.1105/tpc.5.12.1761.
The rha1 gene from Arabidopsis encodes a small GTP binding protein belonging to the Ypt/Rab family. Transgenic Arabidopsis plants containing the promoter region of the rha1 gene fused to the beta-glucuronidase (gus) reporter gene revealed gus expression limited mainly to the guard cells of stomata, the stipules, and the root tip of young plants. In flowering plants, expression was found predominantly in the receptacle and in guard cells of the different flower organs. High GUS activity could also be seen in callus tissue and developing seeds. No detectable activity was present in other plant tissues; activity could not be induced by various treatments. GUS activity was visualized histochemically using both 5-bromo-4-chloro-3-indolyl beta-D-glucuronide and a newly developed GUS substrate: Sudan II-beta-glucuronide. The latter precipitates as red crystals at the site of GUS activity. Results obtained by the gus analysis were confirmed by whole-mount mRNA in situ hybridization. A hypothesis for the function of the Rha1 protein is discussed.
来自拟南芥的rha1基因编码一种属于Ypt/Rab家族的小GTP结合蛋白。含有与β-葡萄糖醛酸酶(gus)报告基因融合的rha1基因启动子区域的转基因拟南芥植株显示,gus表达主要局限于气孔的保卫细胞、托叶和幼嫩植株的根尖。在开花植物中,表达主要出现在花托和不同花器官的保卫细胞中。在愈伤组织和发育中的种子中也能看到高GUS活性。在其他植物组织中未检测到活性;各种处理均不能诱导活性。使用5-溴-4-氯-3-吲哚基β-D-葡萄糖醛酸和一种新开发的GUS底物:苏丹II-β-葡萄糖醛酸,通过组织化学方法使GUS活性可视化。后者在GUS活性位点沉淀为红色晶体。通过gus分析获得的结果通过整体mRNA原位杂交得到证实。讨论了Rha1蛋白功能的一种假说。