Vágújfalvi Attila, Aprile Alessio, Miller Andrea, Dubcovsky Jorge, Delugu Giovanni, Galiba Gábor, Cattivelli Luigi
Agricultural Research Institute of the Hungarian Academy of Sciences, 2462, Martonvasar, Hungary.
Mol Genet Genomics. 2005 Dec;274(5):506-14. doi: 10.1007/s00438-005-0047-y. Epub 2005 Oct 1.
The C-repeat binding factor (Cbf) gene family has been shown to have a critical role in the regulation of low-temperature stress response in Arabidopsis. In Triticum monococcum, a locus carrying a family of Cbf-like genes, orthologs of Arabidopsis Cbf genes, is tightly linked to the frost tolerance locus Fr-A ( m ) 2, representing candidates for the differences in frost tolerance mapped at this locus. In this work we show that several Cbf genes have dramatically different levels of induction after cold exposure in hexaploid wheat. The Cbf-transcription levels differ between substitution and single chromosome recombinant lines carrying different 5A chromosomes or chromosome segments of the chromosome 5A from frost-tolerant and frost-sensitive wheat varieties. When the expression of eight Cbf genes, previously mapped at the Fr-A2 locus was investigated with gene specific primers using real-time RT-PCR, three Cbf sequences (Cbf1A, Cbf1C, Cbf7) showed a significantly higher relative transcription level (more than fourfold change) in lines differing for the Fr-A2 region. Differences in Cbf expression were also associated with a variation in frost tolerance. These results suggest that the amount of some Cbf mRNAs might be a critical factor for determining the level of frost tolerance in wheat.
C-重复结合因子（Cbf）基因家族已被证明在拟南芥低温胁迫反应的调控中起关键作用。在一粒小麦中，一个携带Cbf类基因家族（拟南芥Cbf基因的直系同源基因）的位点与抗冻性位点Fr-A(m)2紧密连锁，这代表了在此位点定位的抗冻性差异的候选基因。在这项研究中，我们发现六倍体小麦在冷暴露后，几个Cbf基因的诱导水平存在显著差异。携带来自抗冻和冻敏感小麦品种不同5A染色体或5A染色体片段的代换系和单染色体重组系之间，Cbf转录水平有所不同。当使用实时RT-PCR，用基因特异性引物研究先前定位在Fr-A2位点的8个Cbf基因的表达时，在Fr-A2区域不同的品系中，3个Cbf序列（Cbf1A、Cbf1C、Cbf7）显示出显著更高的相对转录水平（变化超过四倍）。Cbf表达的差异也与抗冻性的变化相关。这些结果表明，一些Cbf mRNA的量可能是决定小麦抗冻性水平的关键因素。
