College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, 266000, China.
BMC Genomics. 2021 Jan 28;22(1):90. doi: 10.1186/s12864-021-07396-6.
Rose (Rosa chinensis) is a traditional famous flower with valuable ornamental characteristics. However, drought stress restricts its growth and development, leading to an abnormal phenotype. One of the main transcription factor (TF) protein groups in the plant kingdom are the APETALA2/ethylene-responsive factor (AP2/ERF) proteins and are potentially involved in the growth and stress responses of various plants.
Our investigation mainly focused on exploring the genome of rose and thereby we discovered 135 apparent AP2/ERF TFs. Phylogenic analyses revealed that RcAP2/ERF genes are categorized into DREB, Soloist, AP2, and ERF subfamilies, and are further classified these into 17 groups, with the same as Malus domestica and Arabidopsis thaliana. The analysis of the gene structure revealed that the introns ranged from 0 to 9 in number. Pattern examination demonstrated that the RcAP2/ERF predominantly consists of typical AP2 domains, of which the 2nd motif is the most ubiquitous. Distributions of cis-acting elements indicated that members of the AP2/ERF family are frequently involved in growth and development, phytohormone and stress response in rose species. Also, the distribution mapping of the rose chromosomes indicated that AP2/ERF class genes are dispersed among all seven chromosomes. Additionally, we isolated a novel DREB A2 subgroup gene and named it RcDREB2B. Subsequently, the RcDREB2B transcript accumulation was repressed under the mild and severe drought stress in the root samples of rose. RcDREB2B was targeted to the nucleus and exhibited transactivation in yeast cells. The overexpression of RcDREB2B was found to promote sensitivity to a higher salt concentration, ABA, and PEG at the germination and post-germination stages. Twelve putative osmotic and ABA-related genes were impaired in RcDREB2B-overexpressing plants.
The results provide comprehensive information regarding the gene structure, phylogenic, and distribution of the rose AP2/ERF family and bring insight into the complex transcriptional gene regulation of RcAP2/ERF. Findings in this study would also contribute to further understanding of the RcDREB2B gene in rose.
玫瑰（Rosa chinensis）是一种具有珍贵观赏特性的传统名花。然而，干旱胁迫限制了其生长和发育，导致其出现异常表型。AP2/ETHYLENE-RESPONSIVE FACTOR（AP2/ERF）蛋白是植物王国中主要的转录因子（TF）蛋白群之一，可能参与各种植物的生长和应激反应。
我们的研究主要集中在探索玫瑰的基因组，因此我们发现了 135 个明显的 AP2/ERF TF。系统发育分析表明，RcAP2/ERF 基因分为 DREB、Soloist、AP2 和 ERF 亚家族，并进一步分为 17 组，与苹果属和拟南芥属相同。基因结构分析表明，内含子数从 0 到 9 不等。模式检验表明，RcAP2/ERF 主要由典型的 AP2 结构域组成，其中第 2 个基序最为普遍。顺式作用元件的分布表明，AP2/ERF 家族成员经常参与玫瑰物种的生长发育、植物激素和应激反应。此外，玫瑰染色体的分布图谱表明，AP2/ERF 类基因分散在所有 7 条染色体上。此外，我们分离了一个新的 DREB A2 亚组基因，并将其命名为 RcDREB2B。随后，在玫瑰根样本中，RcDREB2B 的转录积累在轻度和重度干旱胁迫下受到抑制。RcDREB2B 靶向细胞核，并在酵母细胞中表现出转录激活活性。在萌发和萌发后阶段，RcDREB2B 的过表达被发现可提高对较高盐浓度、ABA 和 PEG 的敏感性。在 RcDREB2B 过表达植物中，12 个推定的渗透和 ABA 相关基因受损。
这些结果提供了玫瑰 AP2/ERF 家族的基因结构、系统发育和分布的全面信息，并深入了解了 RcAP2/ERF 的复杂转录基因调控。本研究的结果还将有助于进一步了解玫瑰中的 RcDREB2B 基因。
