Alternatively spliced transcripts of Pi-ta blast resistance gene in Oryza sativa
Alternatively spliced transcripts of Pi-ta blast resistance gene in Oryza sativa
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DOI：
10.1016/j.plantsci.2009.07.012
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发表时间：
2009-11-01
期刊：
影响因子：
5.2
通讯作者：
Jia, Yulin
中科院分区：
文献类型：
--
作者：
Costanzo, Stefano;Jia, Yulin
水稻（Oryza sativa L.）的Pi-ta基因对含有同源无毒基因AVR-Pita的稻瘟病小种具有抗性。Pi-ta是一种单拷贝植物抗性(R)基因，其编码的蛋白质属于核苷酸结合位点富亮氨酸重复序列（NBS-LRR）类。在本研究中，我们报道了Pi-ta基因位点的其他剪接事件，新的内含子和与Pi-ta基因相关的新的差异剪接位点的鉴定。共有12个转录本变异，orf范围在945 - 3099 bp之间，编码11个不同的推测产物，分布在315 - 1033个氨基酸之间。其中5个保留完整的NBS-LRR结构域，2个将Pi-ta蛋白的原始NBS-LRR结构域与c端硫氧还蛋白（TRX）结构域偶联。基因表达分析显示，与其他全长或截断的转录本相比，在含有Pi-ta的抗性水稻品种中，编码TRX结构域的转录本变体的表达水平最高。这些Pi-ta的转录后修饰产生一系列转录异构体，可能在R基因调控和/或可能增加蛋白质多样性中发挥重要作用。据我们所知，这项研究首次报道了CC-NBS-LRR基因的选择性剪接，在其5‘或3’端产生截短的同工型，并在其c端包括具有TRX结构域的转录本。爱思唯尔爱尔兰有限公司出版。
The Pi-ta gene in rice (Oryza sativa L.) confers resistance to races of Magnaporthe oryzae B. Couch containing its cognate avirulence gene AVR-Pita. Pi-ta is a single-copy plant resistance (R) gene encoding a protein belonging to the nucleotide-binding site leucine-rich repeat (NBS-LRR) class. In the present study, we report alternative splicing events at the Pi-ta locus, the identification of new introns and novel differentially used splice sites associated with the Pi-ta gene. A total of 12 transcript variants were predicted with ORFs ranging from 945 to 3099 bp and encoding 11 distinct putative products between 315 and 1033 amino acids. Among them, five preserve complete NBS-LRR domains and two couple the original NBS-LRR domain of the Pi-ta protein with a C-terminal thioredoxin (TRX) domain. Gene expression analysis revealed that transcript variants encoding the TRX domain had, in a resistant Pi-ta containing rice variety, the highest level of expression in comparison to the other full length or truncated transcripts. These post-transcriptional modifications of Pi-ta produce a series of transcript isoforms that could have a significant role in the R gene regulation and/or may increase protein diversity. To our knowledge, this study represents the first report of alternative splicing of a CC-NBS-LRR gene producing truncated isoforms at both their 5' or 3' terminus and including transcripts with a TRX domain at their C-terminus. Published by Elsevier Ireland Ltd.