GALACTURONOSYLTRANSFERASE-LIKE5 Is Involved in the Production of Arabidopsis Seed Coat Mucilage
GALACTURONOSYLTRANSFERASE-LIKE5 Is Involved in the Production of Arabidopsis Seed Coat Mucilage
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DOI：
10.1104/pp.113.227041
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发表时间：
2013-11-01
期刊：
影响因子：
7.4
通讯作者：
Hahn, Michael G.
中科院分区：
文献类型：
--
作者：
Kong, Yingzhen;Zhou, Gongke;Hahn, Michael G.
利用分子遗传学、化学和免疫学方法相结合的方法，研究了拟南芥（Arabidopsis thaliana; At 1g 02720;半乳糖醛酸转移酶样5 [AtGATL 5]）中一种假定的半乳糖醛酸转移酶的功能。AtGATL 5在所有植物组织中表达，其中在角果7 DPA中表达水平最高。此外，它的表达正调控的几个转录因子，已知调节种皮粘液的生产。AtGATL 5定位于内质网和高尔基体，与这些亚细胞区室的标记蛋白相比。AtGATL 5基因中的转移DNA插入会导致种皮表皮细胞在粘液合成和细胞粘附方面出现缺陷。用野生型AtGATL 5基因转化atgatl 5 -1突变体导致所有形态表型的互补。从atgatl 5 -1突变体中分离的粘液的组成分析表明，与野生型粘液相比，atgatl 5 -1中的半乳糖醛酸和鼠李糖含量显著降低。从野生型和突变体种子分离的可溶性粘液之间的结构没有观察到变化，除了突变体粘液的分子量增加了63%，与野生型相比。这些数据提供了证据表明AtGATL 5可能在调节粘液鼠李糖半乳糖醛酸聚糖I的最终大小中起作用。
The function of a putative galacturonosyltransferase from Arabidopsis (Arabidopsis thaliana; At1g02720; GALACTURONOSYLTRANSFERASE-LIKE5 [AtGATL5]) was studied using a combination of molecular genetic, chemical, and immunological approaches. AtGATL5 is expressed in all plant tissues, with highest expression levels in siliques 7 DPA. Furthermore, its expression is positively regulated by several transcription factors that are known to regulate seed coat mucilage production. AtGATL5 is localized in both endoplasmic reticulum and Golgi, in comparison with marker proteins resident to these subcellular compartments. A transfer DNA insertion in the AtGATL5 gene generates seed coat epidermal cell defects both in mucilage synthesis and cell adhesion. Transformation of atgatl5-1 mutants with the wild-type AtGATL5 gene results in the complementation of all morphological phenotypes. Compositional analyses of the mucilage isolated from the atgatl5-1 mutant demonstrated that galacturonic acid and rhamnose contents are decreased significantly in atgatl5-1 compared with wild-type mucilage. No changes in structure were observed between soluble mucilage isolated from wild-type and mutant seeds, except that the molecular weight of the mutant mucilage increased 63% compared with that of the wild type. These data provide evidence that AtGATL5 might function in the regulation of the final size of the mucilage rhamnogalacturonan I.