Flower-predominant expression of a gene encoding a novel class I chitinase in rice (Oryza sativa L.)
Flower-predominant expression of a gene encoding a novel class I chitinase in rice (Oryza sativa L.)
复制标题
DOI：
10.1023/a:1006401816145
复制
发表时间：
2000-04-01
影响因子：
5.1
通讯作者：
Kuwata, S
中科院分区：
文献类型：
--
作者：
Takakura, Y;Ito, T;Kuwata, S
从水稻雌蕊的 cDNA 文库中分离出一种名为 OsChia1;175 的花主导基因 cDNA。 Northern blot和RT-PCR分析表明，OsChia1;175基因在花器官（抽穗期的雌蕊、雄蕊和浆片）中高表达，但在营养器官中不表达或表达水平极低。 OsChia1;175 编码由 340 个氨基酸残基组成的蛋白质，推定的成熟蛋白质与水稻或其他植物的 I 类几丁质酶具有 52% 至 63% 的氨基酸同一性。系统发育树显示OsChia1;175蛋白是水稻中一种新型植物I类几丁质酶。 OsChia1;175 在营养器官中的表达不受多种化学品、紫外线和创伤的诱导。在以胶体几丁质为底物的测定中，大肠杆菌中表达的可溶性推定成熟OsChia1;175蛋白表现出几丁质酶活性。基因组 Southern 分析显示 OsChia1;175 基因被组织为低拷贝基因家族。对水稻基因组文库进行筛选，分离出对应于OsChia1;175的基因组克隆。通过引物延伸分析绘制 OsChia1;175 基因的转录起始位点。 OsChia1;175 基因的 1.2 kb 推定启动子区域与 GUS（β-葡萄糖醛酸酶）基因融合，并通过农杆菌介导的转化将该嵌合基因引入水稻。在转基因水稻植物中也鉴定出了花主导基因的表达。在转基因植物的柱头、花柱、雄蕊和浆片中检测到高启动子活性。讨论了 OsChia1;175 的可能功能。
A flower-predominant cDNA for a gene, termed OsChia1;175, was isolated from a cDNA library of rice pistils. Northern blot and RT-PCR analyses revealed that the OsChia1;175 gene is highly expressed in floral organs (pistils, stamens and lodicules at the heading stage) but not or at an extremely low level in vegetative organs. OsChia1;175 encodes a protein that consists of 340 amino acid residues, and the putative mature protein shows 52% to 63% amino acid identity to class I chitinases of rice or other plants. The phylogenetic tree shows that the OsChia1;175 protein is a new type of plant class I chitinase in rice. The expression of OsChia1;175 in vegetative organs is not induced by several chemicals, UV, and wounding. The soluble putative mature OsChia1;175 protein expressed in Escherichia coli exhibited chitinase activity in the assay with colloidal chitin as a substrate. Genomic Southern analysis revealed that the OsChia1;175 gene was organized as a low-copy gene family. The rice genomic library was screened and a genome clone corresponding to OsChia1;175 was isolated. The transcription start sites of the OsChia1;175 gene were mapped by primer extension analysis. The 1.2 kb putative promoter region of the OsChia1;175 gene was fused to the GUS (beta-glucuronidase) gene, and this chimeric gene was introduced to rice by Agrobacterium-mediated transformation. The flower-predominant gene expression was identified also in the transgenic rice plants. The high promoter activity was detected in the stigmas, styles, stamens and lodicules in transgenic plants. The possible functions of OsChia1;175 are discussed.