A novel extensin gene encoding a hydroxyproline-rich glycoprotein requires sucrose for its wound-inducible expression in transgenic plants
A novel extensin gene encoding a hydroxyproline-rich glycoprotein requires sucrose for its wound-inducible expression in transgenic plants
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DOI：
10.1105/tpc.8.9.1477
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发表时间：
1996-09-01
期刊：
影响因子：
11.6
通讯作者：
Lee, JS
中科院分区：
文献类型：
--
作者：
Ahn, JH;Choi, Y;Lee, JS
一种新的富含羟脯氨酸的糖蛋白（SbHRGP 3），由两个不同的结构域组成的大豆extensin基因编码。位于N端的第一结构域（结构域1）由Ser-Pro（4）-Lys-His-Ser-Pro（4）-Tyr（3）-His的11个重复组成，而位于C端的第二结构域（结构域2）包含Ser-Pro（4）-Val-Tyr-Lys-Tyr-Lys-Ser-Pro（4）-Tyr-Lys-Tyr-Pro-Ser-Pro（5）-Tyr-Lys-Tyr-Pro-Ser-Pro（4）-Val-Tyr-Lys-Tyr-Lys。这两个重复基序在每个结构域中以非常有序的模式组织，这表明SbHRGP 3属于一组新的蛋白质，具有两组不同的双子叶植物延伸素的重复基序。SbHRGP 3基因的表达量随着幼苗的成熟而增加，并且其在大豆幼苗的下胚轴和根的成熟区域中的表达量相对较高。构建了SbHRGP 3-β-葡萄糖醛酸酶（SbHRGP 3-GUS）嵌合基因，并在转基因烟草中表达。SbHRGP 3-GUS基因的表达不能通过单独的创伤在转基因烟草植株中诱导;蔗糖也是必需的。表达在韧皮部组织和叶、茎形成层细胞中具有特异性。在转基因烟草幼苗中，SbHRGP 3-GUS基因的表达被激活的主根的成熟，然后失活，然而，重新激活是专门在该区域的侧根被启动的表皮。它的再激活发生在侧根发生之前。这些结果表明，不同组织中的SbHRGP 3基因对不同的信号作出反应。
A novel hydroxyproline-rich glycoprotein (SbHRGP3) that consists of two different domains is encoded by an extensin gene from soybean. The first domain (domain 1) located at the N terminus is composed of 11 repeats of Ser-Pro(4)-Lys-His-Ser-Pro(4)-Tyr(3)-His, whereas the second domain (domain 2) at the C terminus contains five repeats of Ser-Pro(4)-Val-Tyr-Lys-Tyr-Lys-Ser-Pro(4)-Tyr-Lys-Tyr-Pro-Ser -Pro(5)-Tyr-Lys-Tyr-Pro-Ser-Pro(4)-Val-Tyr-Lys-Tyr-Lys. These two repeat motifs are organized in an extremely well-ordered pattern in each domain, which suggests that SbHRGP3 belongs to a new group of proteins having the repeat motifs of two distinct groups of dicot extensins. The expression of the SbHRGP3 gene increased with seedling maturation, and its expression was relatively high in the mature regions of the hypocotyl and in the root of soybean seedlings. An SbHRGP3-beta-glucuronidase (SbHRGP3-GUS) chimeric gene was constructed and expressed in transgenic tobacco plants. The expression of the SbHRGP3-GUS gene was not induced by wounding alone in transgenic tobacco plants; sucrose was also required. Expression was specific to phloem tissues and cambium cells of leaves and stems. In transgenic tobacco seedlings, SbHRGP3-GUS gene expression was activated by the maturation of the primary root and then inactivated; however, reactivation was specifically at the epidermis of the zone from which the lateral root was to be initiated. Its reactivation occurred just before the lateral root initiation. These results indicate that the SbHRGP3 gene in different tissues responds to different signals.