DELLA protein plays a significant role in plant growth and development. In this study, PlDELLA with the open reading frame of 1866 bp in length was isolated from Paeonia lactiflora. Overexpression of PlDELLA in Arabidopsis thaliana showed that seed germination was significantly repressed as it took 144∼192 h for the OEs to reach 100 % germination and it required only 60 h for the WT. The OEs were also inhibited in bolting time and in plant vegetative growth. When PlDELLA was silenced in peony by virus-induced gene silencing method, peony budbreak occurred earlier by 8∼10 d and the vegetative growth was significantly accelerated compared with the control group. These results collectively indicated that PlDELLA negatively regulated dormancy release and plant growth. During chilling process to release peony endodormancy, PlDELLA expression down-regulated, and the content of both endogenous active GAs and ABA decreased, indicating decreasing of PlDELLA expression under chilling was not caused by the known gibberellin signal transduction pathway. Besides, PlDELLA had no interaction with the four screened PlWRKYs, PlWRKY13, PlWRKY18, PlWRKY40 or PlWRKY50. These findings not only enrich the knowledge of DELLA protein family, but also provide insights into understanding the function of PlDELLA protein in endodormancy release in peony.

中文翻译：

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草本牡丹 (Paeonia lactiflora Pall.) PlDELLA 基因负调控休眠解除和植物生长

DELLA 蛋白在植物生长发育中起着重要作用。本研究从芍药中分离得到开放阅读框长度为1866 bp的PlDELLA。PlDELLA 在拟南芥中的过表达表明种子萌发受到显着抑制，因为 OE 需要 144~192 小时才能达到 100% 萌发，而 WT 只需要 60 小时。OEs 在抽薹时间和植物营养生长方面也受到抑制。用病毒诱导基因沉默方法在牡丹中沉默PlDELLA时，牡丹萌发提前8～10 d，营养生长较对照组明显加快。这些结果共同表明，PlDELLA 负向调节休眠释放和植物生长。在冷却过程中释放牡丹内眠，PlDELLA 表达下调，内源性活性GAs 和ABA 含量均降低，表明低温下PlDELLA 表达的降低不是由已知的赤霉素信号转导途径引起的。此外，PlDELLA 与四个筛选的 PlWRKYs、PlWRKY13、PlWRKY18、PlWRKY40 或 PlWRKY50 没有相互作用。这些发现不仅丰富了 DELLA 蛋白家族的知识，而且为理解 PlDELLA 蛋白在牡丹内眠释放中的功能提供了见解。