Isolation and molecular characterization of a Spotted leaf 18 mutant by modified activation-tagging in rice
Isolation and molecular characterization of a Spotted leaf 18 mutant by modified activation-tagging in rice
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DOI：
10.1007/s11103-006-9130-y
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发表时间：
2007-04-01
影响因子：
5.1
通讯作者：
Kikuchi, Shoshi
中科院分区：
文献类型：
--
作者：
Mori, Masaki;Tomita, Chikako;Kikuchi, Shoshi
从13000个水稻激活标记株系中分离到一个突变体，我们将其命名为斑点叶18 （Spl18）。Spl18是显性的，其表型与T-DNA插入有关。一个ORF位于插入的T-DNA下游约500 bp处，推断出的蛋白被命名为OsAT1，其序列与烟草过敏反应诱导的酰基转移酶相似。OsAT1在WT叶片中转录水平极低，而在Spl18叶片中转录水平较高。在野生型水稻中，OsAT1主要在幼穗、抽穗后穗和叶鞘中转录。此外，Spl18中PR蛋白基因的转录上调，植物抗菌素（momilactone A和sakururetin）的积累增加，提高了对瘟病的抗性。然后，我们将修改后的35S启动子下游的OsAT1基因组DNA结合，并将其重新转化到水稻中。在转基因株系中检测到病变模拟表型和blast抗性表型，清楚地表明OsAT1过表达导致Spl18表型。此外，过表达OsAT1的植株对白叶枯病具有抗性。
A lesion mimic mutant that we designated Spotted leaf 18 (Spl18) was isolated from 13,000 activation-tagging lines of rice produced by our modified activation-tagging vector and further characterized. Spl18 was dominant and its phenotype was linked to the T-DNA insertion. An ORF was located about 500 bp downstream of the inserted T-DNA, and the deduced protein, designated OsAT1, showed sequence similarity to an acyltransferase whose expression is induced by hypersensitive reaction in tobacco. The transcriptional level of OsAT1 was very low in the WT leaf blade but high in Spl18 leaf blade. In wild-type rice, OsAT1 was transcribed mainly in the young panicle, in the panicle just after heading, and in the leaf sheath. In addition, transcription of the genes for PR protein was upregulated in Spl18, accumulation of phytoalexins (both momilactone A and sakuranetin) was increased, and resistance to blast disease was improved. We then combined OsAT1 genomic DNA downstream of the modified 35S promoter and re-transformed it into rice. Lesion mimic and blast resistance phenotypes were detected in the transgenic lines produced, clearly indicating that overexpression of OsAT1 caused the Spl18 phenotypes. In addition, plants overexpressing OsAT1 showed resistance to bacterial blight.