Identification of Two Plastid-Targeted β-Amylases in Rice
Identification of Two Plastid-Targeted β-Amylases in Rice
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DOI：
10.1626/pps.14.318
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发表时间：
2011-10-01
影响因子：
2.5
通讯作者：
Michiyama, Hiroyasu
中科院分区：
文献类型：
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作者：
Hirano, Tatsuya;Takahashi, Yusuke;Michiyama, Hiroyasu
为了鉴定水稻（Oryza sativa L.）质体内的β -淀粉酶同工型，我们在水稻基因组数据库中检索了预测编码β -淀粉酶样蛋白的基因，并将其命名为OsBAM1-9。OsBAM1、OsBAM7和OsBAM9基因主要在种子萌发和颖果发育过程中表达。OsBAM2、OsBAM3、OsBAM4和OsBAM5的转录本主要在抽穗后的叶片、叶鞘和节间中检测到，它们的n端区域可能存在叶绿体转运肽。含有重组OsBAM2和OsBAM3蛋白的大肠杆菌制备的可溶性蛋白组分具有显著的β -淀粉酶活性。此外，引入洋葱鳞茎表皮的OsBAM2-GFP和OsBAM3-GFP融合蛋白被定位到质体中。这些结果强烈提示OsBAM2和OsBAM3是质体靶向活性β -淀粉酶。
In order to identify beta-amylase isoforms acting inside plastids in rice (Oryza sativa L.), in the rice genome database we searched the genes predicted to encode beta-amylase-like proteins, and designated them OsBAM1-9. OsBAM1, OsBAM7, and OsBAM9 genes were mainly expressed in germinating seeds and developing caryopses. In contrast, the transcripts of OsBAM2, OsBAM3, OsBAM4 and OsBAM5, which have a putative chloroplast transit peptide in their N-terminal regions, were mainly detected in leaf blades, leaf sheaths and internodes after heading. Soluble protein fractions prepared from Escherichia con containing recombinant OsBAM2 and OsBAM3 proteins had significant beta-amylase activity. Furthermore, OsBAM2-GFP and OsBAM3-GFP fusion proteins introduced into epidermis of Allium cepa scaly bulb were localized to the plastids. These results strongly suggest that OsBAM2 and OsBAM3 are plastid-targeted active beta-amylase.