肌动蛋白解聚因子(ADF),作为重要的肌动蛋白结合蛋白(ABP)与解聚/切断肌动蛋白丝,在植物生长发育中起着至关重要的作用,以及对生物和非生物胁迫的反应。然而,甜瓜ADF家族的信息和功能尚不清楚。在这项研究中,鉴定出9个甜瓜ADF基因(CmADFs),分布在4个亚科,分别位于6条染色体上。启动子分析表明,CmADF含有大量与激素和应激相关的顺式作用元件。CmADFs与其拟南芥同源物AtADFs的序列相似性,结构,重要部位和组织表达证实ADF是保守的。基因表达分析表明,CmADFs对低温和高温胁迫有响应,以及ABA和SA信号。特别是,在上述所有应激和激素治疗下,CmADF1显著上调,表明CmADF1在应激和激素信号反应中起关键作用,因此选择CmADF1进一步研究其在植物耐低温中的作用机制。在低温下,东方甜瓜植物中CmADF1的病毒诱导基因沉默(VIGS)显示出对低温胁迫的敏感性增加。始终如一,CmADF1在拟南芥中稳定的遗传过表达提高了其耐低温性,可能是由于CmADF1在肌动蛋白丝解聚中的作用。总的来说,我们的发现表明CmADF基因,尤其是CmADF1,在甜瓜中对非生物胁迫的反应中起作用。
Actin depolymerizing factors (ADFs), as the important actin-binding proteins (ABPs) with depolymerizing/severing actin filaments, play a critical role in plant growth and development, and in response to biotic and abiotic stresses. However, the information and function of the ADF family in melon remains unclear. In this study, 9 melon ADF genes (CmADFs) were identified, distributed in 4 subfamilies, and located on 6 chromosomes respectively. Promoter analysis revealed that the CmADFs contained a large number of cis-acting elements related to hormones and stresses. The similarity of CmADFs with their Arabidopsis homologue AtADFs in sequence, structure, important sites and tissue expression confirmed that ADFs were conserved. Gene expression analysis showed that CmADFs responded to low and high temperature stresses, as well as ABA and SA signals. In particular, CmADF1 was significantly up-regulated under above all stress and hormone treatments, indicating that CmADF1 plays a key role in stress and hormone signaling responses, so CmADF1 was selected to further study the mechanism in plant tolerance low temperature. Under low temperature, virus-induced gene silencing (VIGS) of CmADF1 in oriental melon plants showed increased sensitivity to low temperature stress. Consistently, the stable genetic overexpression of CmADF1 in Arabidopsis improved their low temperature tolerance, possibly due to the role of CmADF1 in the depolymerization of actin filaments. Overall, our findings indicated that CmADF genes, especially CmADF1, function in response to abiotic stresses in melon.