Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
Plant Physiol Biochem. 2011 Apr;49(4):420-6. doi: 10.1016/j.plaphy.2011.01.017. Epub 2011 Jan 21.
The identification and expression of two ACC oxidase (ACO) genes during leaf development in Trifolium occidentale (L.), one of the putative ancestral genomes of the allotetraploid, T. repens (L.; white clover), is described. In common with observations made in T. repens, the ACO genes displayed differential expression, with a TR-ACO2-like gene (designated TO-ACO2) confined to developing and early mature-green leaf tissue while expression of a TR-ACO3-like gene (designated TO-ACO3) is highest in leaves at the onset and during senescence. Biochemical analysis of TO-ACO2 revealed that both accumulation of the protein (determined by western analysis with a TR-ACO2 antibody) and enzyme activity matched the transcriptional activity of TO-ACO2. Western analysis also revealed that the Tr-ACO2 antibody recognised a protein of 37 kDa as a putative TP-ACO2 in T. pallescens. The 3'-UTRs of TO-ACO2 and TO-ACO3 were then compared with the 3'-UTRs of a TR-ACO2-like and TR-ACO3-like gene from T. pallescens, the other proposed ancestral genome (or closely related to the ancestor) of T. repens, with identity values of 87.8% for the ACO2-like genes and 94.8% for the ACO3-like genes. Comparison of the 3'-UTRs of TO-ACO2 with a TO-ACO2-like gene in T. repens (designated TR(O)-ACO2) and TP-ACO2 with a TP-ACO2-like gene in T. repens (designated TR(P)-ACO2) revealed identities of 100% and 96.6%, respectively, lending good support to T. occidentale as one of the ancestral genomes of T. repens. A similar comparison of the 3'-UTRs of TO-ACO3 with a TO-ACO3-like gene in T. repens (designated TR(O)-ACO3) and TP-ACO3 with a TP-ACO3-like gene in T. repens (designated TR(P)-ACO3) revealed identities of 99.5% and 97.9%, respectively, again supporting T. occidentale as one of the ancestral genomes. Further, these data confirm that both TO-ACO-like and TP-ACO-like genes are expressed in the allotetraploid T. repens.
描述了在三叶草属（Trifolium occidentale（L.））中发现的两个 ACC 氧化酶（ACO）基因的鉴定和表达，三叶草属是异源四倍体白三叶草（T. repens（L.）的可能祖先之一。与在白三叶草中观察到的情况一样，ACO 基因表现出差异表达，TR-ACO2 样基因（指定为 TO-ACO2）局限于发育中和早期成熟的绿叶组织中，而 TR-ACO3 样基因（指定为 TO-ACO3）的表达在衰老开始和期间最高。TO-ACO2 的生化分析表明，蛋白质的积累（通过与 TR-ACO2 抗体的 Western 分析确定）和酶活性与 TO-ACO2 的转录活性相匹配。Western 分析还表明，Tr-ACO2 抗体在 T. pallescens 中识别出一种 37 kDa 的蛋白，这是一种推定的 TP-ACO2。然后将 TO-ACO2 和 TO-ACO3 的 3'-UTR 与来自 T. pallescens 的 TR-ACO2 样和 TR-ACO3 样基因的 3'-UTR 进行比较，T. pallescens 是白三叶草的另一个提议的祖先基因组（或与祖先密切相关），ACO2 样基因的同一性值为 87.8%，ACO3 样基因的同一性值为 94.8%。将 TO-ACO2 的 3'-UTR 与白三叶草中的 TO-ACO2 样基因（指定为 TR（O）-ACO2）和 TP-ACO2 与白三叶草中的 TP-ACO2 样基因（指定为 TR（P）-ACO2）进行比较，结果分别为 100%和 96.6%，这对白三叶草作为白三叶草的祖先基因组之一提供了很好的支持。将 TO-ACO3 的 3'-UTR 与白三叶草中的 TO-ACO3 样基因（指定为 TR（O）-ACO3）和 TP-ACO3 与白三叶草中的 TP-ACO3 样基因（指定为 TR（P）-ACO3）进行比较，结果分别为 99.5%和 97.9%，再次支持白三叶草作为祖先基因组之一。此外，这些数据证实，TO-ACO 样和 TP-ACO 样基因都在异源四倍体白三叶草中表达。
