Flemetakis Emmanouil, Dimou Maria, Cotzur Daniela, Efrose Rodica C, Aivalakis Georgios, Colebatch Gillian, Udvardi Michael, Katinakis Panagiotis
Agricultural University of Athens, Department of Agricultural Biotechnology, Iera Odos 75, 118 55 Athens, Greece.
J Exp Bot. 2003 Jul;54(388):1789-91. doi: 10.1093/jxb/erg179. Epub 2003 May 13.
LjSUT4, encoding a putative sucrose transporter, was identified in a Lotus japonicus nodule cDNA library. The deduced amino acid sequence showed a high degree of identity with sucrose transporters from other plants. Semi-quantitative RT-PCR analysis demonstrated that the L. japonicus SUT4 gene was expressed at high levels in both roots and nodules. In situ hybridization revealed that, in young nodules, SUT4 mRNA transcripts are present in vascular bundles, inner cortex and both infected and uninfected cells while, in mature nodules, accumulation of transcripts was restricted only in vascular bundles and the inner cortex. The results indicated that LjSUT4 codes for a putative sucrose transporter, and its expression pattern suggests a possible shift in the mechanism of sugar transport during nodule development. The role of this polypeptide in sucrose transport and metabolism is discussed.
LjSUT4编码一种假定的蔗糖转运蛋白，是在日本百脉根根瘤cDNA文库中鉴定出来的。推导的氨基酸序列与其他植物的蔗糖转运蛋白具有高度同源性。半定量RT-PCR分析表明，日本百脉根SUT4基因在根和根瘤中均高水平表达。原位杂交显示，在幼根瘤中，SUT4 mRNA转录本存在于维管束、内皮层以及受感染和未受感染的细胞中，而在成熟根瘤中，转录本的积累仅局限于维管束和内皮层。结果表明LjSUT4编码一种假定的蔗糖转运蛋白，其表达模式表明在根瘤发育过程中糖转运机制可能发生了转变。本文讨论了该多肽在蔗糖转运和代谢中的作用。
