State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Key Laboratory for Postharvest Science, College of Horticultural Science, South China Agricultural University, Guangzhou 510642, PR China.
J Exp Bot. 2012 Jan;63(1):441-54. doi: 10.1093/jxb/err290. Epub 2011 Sep 16.
Histone deacetylation plays an important role in epigenetic control of gene expression. HD2 is a plant-specific histone deacetylase that is able to mediate transcriptional repression in many biological processes. To investigate the epigenetic and transcriptional mechanisms of longan fruit senescence, one histone deacetylase 2-like gene, DlHD2, and two ethylene-responsive factor-like genes, DlERF1 and DlERF2, were cloned and characterized from longan fruit. Expression of these genes was examined during fruit senescence under different storage conditions. The accumulation of DlHD2 reached a peak at 2 d and 30 d in the fruit stored at 25 °C (room temperature) and 4 °C (low temperature), respectively, or 6 h after the fruit was transferred from 4 °C to 25 °C, when fruit senescence was initiated. However, the DlERF1 transcript accumulated mostly at the later stage of fruit senescence, reaching a peak at 5 d and 35 d in the fruit stored at 25 °C and 4 °C, respectively, or 36 h after the fruit was transferred from low temperature to room temperature. Moreover, application of nitric oxide (NO) delayed fruit senescence, enhanced the expression of DlHD2, but suppressed the expression of DlERF1 and DlERF2. These results indicated a possible interaction between DlHD2 and DlERFs in regulating longan fruit senescence, and the direct interaction between DlHD2 and DlERF1 was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. Taken together, the results suggested that DlHD2 may act with DlERF1 to regulate gene expression involved in longan fruit senescence.
组蛋白去乙酰化在基因表达的表观遗传调控中发挥着重要作用。HD2 是一种植物特异性的组蛋白去乙酰化酶，能够在许多生物过程中介导转录抑制。为了研究龙眼果实衰老的表观遗传和转录机制，我们从龙眼果实中克隆并鉴定了一个组蛋白去乙酰化酶 2 样基因 DlHD2 和两个乙烯响应因子样基因 DlERF1 和 DlERF2。研究了这些基因在不同贮藏条件下果实衰老过程中的表达情况。在 25°C（室温）和 4°C（低温）下贮藏的果实中，DlHD2 的积累分别在 2 d 和 30 d 达到峰值，或者在果实从 4°C 转移到 25°C 后 6 h 时，果实衰老开始。然而，DlERF1 转录本主要在果实衰老后期积累，在 25°C 和 4°C 下贮藏的果实中分别在 5 d 和 35 d 达到峰值，或者在果实从低温转移到室温后 36 h 达到峰值。此外，一氧化氮（NO）的应用延缓了果实衰老，增强了 DlHD2 的表达，但抑制了 DlERF1 和 DlERF2 的表达。这些结果表明，DlHD2 可能与 DlERFs 相互作用调节龙眼果实衰老，并且通过酵母双杂交和双分子荧光互补（BiFC）实验证实了 DlHD2 与 DlERF1 之间的直接相互作用。综上所述，这些结果表明 DlHD2 可能与 DlERF1 一起调节参与龙眼果实衰老的基因表达。
