Laboratory of Genetic Engineering, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.
Plant Cell Rep. 2011 Apr;30(4):519-27. doi: 10.1007/s00299-010-0962-1. Epub 2010 Dec 8.
Carnation (Dianthus caryophyllus) flowers exhibit climacteric ethylene production followed by petal wilting, a senescence symptom. DcACS1, which encodes 1-aminocyclopropane-1-carboxylate synthase (ACS), is a gene involved in this phenomenon. We determined the genomic DNA structure of DcACS1 by genomic PCR. In the genome of 'Light Pink Barbara', we found two distinct nucleotide sequences: one corresponding to the gene previously shown as DcACS1, designated here as DcACS1a, and the other novel one designated as DcACS1b. It was revealed that both DcACS1a and DcACS1b have five exons and four introns. These two genes had almost identical nucleotide sequences in exons, but not in some introns and 3'-UTR. Analysis of transcript accumulation revealed that DcACS1b is expressed in senescing petals as well as DcACS1a. Genomic PCR analysis of 32 carnation cultivars showed that most cultivars have only DcACS1a and some have both DcACS1a and DcACS1b. Moreover, we found two DcACS1 orthologous genes with different nucleotide sequences from D. superbus var. longicalycinus, and designated them as DsuACS1a and DsuACS1b. Petals of D. superbus var. longicalycinus produced ethylene in response to exogenous ethylene, accompanying accumulation of DsuACS1 transcripts. These data suggest that climacteric ethylene production in flowers was genetically established before the cultivation of carnation.
香石竹（Dianthus caryophyllus）花朵表现出跃变型乙烯生成，随后花瓣萎蔫，这是衰老的症状。编码 1-氨基环丙烷-1-羧酸合酶（ACS）的 DcACS1 基因参与了这一现象。我们通过基因组 PCR 确定了 DcACS1 的基因组 DNA 结构。在 'Light Pink Barbara' 的基因组中，我们发现了两个不同的核苷酸序列：一个与先前被认为是 DcACS1 的基因相对应，这里称为 DcACS1a，另一个是新的，称为 DcACS1b。结果表明，DcACS1a 和 DcACS1b 都有五个外显子和四个内含子。这两个基因在外显子中具有几乎相同的核苷酸序列，但在一些内含子和 3'-UTR 中则不同。转录物积累分析表明，DcACS1b 像 DcACS1a 一样在衰老的花瓣中表达。对 32 个香石竹品种的基因组 PCR 分析表明，大多数品种只有 DcACS1a，而有些品种既有 DcACS1a 又有 DcACS1b。此外，我们从 D. superbus var. longicalycinus 中发现了两个具有不同核苷酸序列的 DcACS1 同源基因，并将它们命名为 DsuACS1a 和 DsuACS1b。D. superbus var. longicalycinus 的花瓣对外源乙烯产生乙烯反应，同时积累 DsuACS1 转录物。这些数据表明，在香石竹栽培之前，花朵中就已经存在跃变型乙烯生成的遗传基础。
