Genomics of Plant Stress Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
Tree Physiol. 2012 Sep;32(9):1113-28. doi: 10.1093/treephys/tps067. Epub 2012 Jul 25.
Low temperature plays a crucial role in seasonal development of woody plants and may directly impact crop production, more particularly in temperate fruit trees. Given its high genetic variability and adaptability to different climatic conditions, almond (Prunus dulcis Mill.) is an interesting model to understand the mechanisms regulating low temperature sensing in fruit trees. In this paper, we report the cloning and characterization of two genes (PdCBF1 and PdCBF2) belonging to the C-repeat-binding factor (CBF) family of transcription factors. Southern blotting analysis showed that this family is composed of at least five members. In almond shoots propagated in vitro, transcription of these genes was rapidly induced by low temperature, suggesting an involvement in cold acclimation. Transactivation assays showed that PdCBF1 and PdCBF2 could bind to dehydration responsive element/C-repeat containing sequences, as activators of gene expression. In addition, induction of both PdCBFs by cold was higher towards the end of the day, which agreed with the expression pattern of PdDehydrin1, a predicted CBF target gene. Furthermore, PdCBF1 and PdCBF2 were also transiently induced by abscisic acid and drought treatments. Considering the bin mapping analysis that correlated PdCBFs and PdDHN1 (respectively in linkage groups 5 and 7) with two different quantitative trait locicontrolling blooming time, it is relevant to perform further association studies that may validate their effect on this trait.
低温在木本植物的季节性发育中起着至关重要的作用，可能直接影响作物生产，特别是在温带果树中。鉴于杏仁（Prunus dulcis Mill.）具有高度的遗传变异性和对不同气候条件的适应性，它是研究低温感应在果树上的调控机制的一个有趣模型。在本文中，我们报道了两个基因（PdCBF1 和 PdCBF2）的克隆和特征，这两个基因属于 C 重复结合因子（CBF）家族的转录因子。Southern 印迹分析表明，该家族至少由五个成员组成。在体外繁殖的杏仁芽中，这些基因的转录被低温迅速诱导，表明它们参与了低温适应。转录激活试验表明，PdCBF1 和 PdCBF2 可以与脱水响应元件/C 重复序列结合，作为基因表达的激活剂。此外，低温对这两种 PdCBFs 的诱导作用在一天结束时更高，这与预测的 CBF 靶基因 PdDehydrin1 的表达模式一致。此外，PdCBF1 和 PdCBF2 也被脱落酸和干旱处理瞬时诱导。考虑到将 PdCBFs 和 PdDHN1（分别在连锁群 5 和 7 中）与两个不同的控制开花时间的数量性状基因座相关联的 bin 映射分析，进行进一步的关联研究是相关的，这可能验证它们对该性状的影响。
