Stacey Minviluz G, Koh Serry, Becker Jeffrey, Stacey Gary
Department of Plant Microbiology and Pathology, University of Missouri, Columbia, Missouri 65211, USA.
Plant Cell. 2002 Nov;14(11):2799-811. doi: 10.1105/tpc.005629.
A T-DNA-tagged population of Arabidopsis was screened for mutations in AtOPT3, which encodes a member of the oligopeptide (OPT) family of peptide transporters, and a recessive mutant allele, opt3, was identified. Phenotypic analysis of opt3 showed that most homozygous embryos were arrested at or before the octant stage of embryo development and that none showed the usual periclinal division leading to the formation of the protoderm. This defective phenotype could be reversed by complementation with the full-length, wild-type AtOPT3 gene. A beta-glucuronidase (GUS) fusion to DNA sequences upstream of the putative AtOPT3 ATG start codon was constructed, and the expression pattern was assayed in transgenic plants. AtOPT3 was expressed in the vascular tissues of seedlings and mature plants as well as in pollen. Consistent with the function of AtOPT3 in embryogenesis, AtOPT3::GUS expression also was detected in developing embryos and in the maternal tissues of seeds. These data suggest a critical role for peptide transport in early embryo development.
对一个拟南芥T-DNA标签群体进行筛选，以寻找AtOPT3（编码肽转运蛋白寡肽（OPT）家族的一个成员）中的突变，并且鉴定出一个隐性突变等位基因opt3。对opt3的表型分析表明，大多数纯合胚胎在胚胎发育的八分体阶段或之前就停止发育，并且没有一个表现出导致原表皮形成的正常平周分裂。通过用全长野生型AtOPT3基因进行互补，可以逆转这种缺陷表型。构建了一个与推定的AtOPT3 ATG起始密码子上游DNA序列融合的β-葡萄糖醛酸酶（GUS），并在转基因植物中检测其表达模式。AtOPT3在幼苗和成熟植物的维管组织以及花粉中表达。与AtOPT3在胚胎发生中的功能一致，在发育中的胚胎和种子的母体组织中也检测到AtOPT3::GUS表达。这些数据表明肽转运在早期胚胎发育中起关键作用。
