AUTHOR=Li Qingfei , Zhang Li , Chen Peiwen , Wu Chunhui , Zhang Huaixia , Yuan Jingping , Zhou Junguo , Li Xinzheng 

TITLE=Genome-Wide Identification of APETALA2/ETHYLENE RESPONSIVE FACTOR Transcription Factors in Cucurbita moschata and Their Involvement in Ethylene Response

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.847754

DOI=10.3389/fpls.2022.847754

ISSN=1664-462X

ABSTRACT=<p><italic>APETALA2/ETHYLENE RESPONSIVE FACTOR</italic> (<italic>AP2/ERF</italic>), a plant-specific transcription factor (TF) family, plays an essential role in the growth and development of plants, and in their response to biotic and abiotic stresses. However, information on <italic>AP2/ERF</italic> in <italic>Cucurbita moschata</italic> (pumpkin), an edible and medicinal vegetable used worldwide, is scarce. A total of 212 <italic>AP2/ERF</italic> genes were identified in the <italic>C. moschata</italic> genome (<italic>CmoAP2/ERFs</italic>). Based on phylogenetic analysis, they were divided into four groups—28 AP2s, 92 ERFs, 86 dehydration-responsive element-binding (DREB) factors, and 6 ABI3/VPs (RAV). The 212 <italic>AP2/ERF</italic> genes were unevenly distributed on the 20 chromosomes of <italic>C. moschata</italic>. The results of structural analysis showed the absence of introns on 132 <italic>CmoAP2/ERFs</italic>. Four pairs of tandem duplication and 155 pairs of segmental duplication events were identified, which indicated that segmental duplications might be the main reason for the expansion of the CmoAP2/ERF family. The analysis of <italic>cis</italic>-regulatory elements (CREs) showed that most of the <italic>CmoAP2/ERFs</italic> contained hormone response elements (ABREs, EREs) in their promoters, suggesting that AP2/ERFs could contribute to the processes regulated by ethylene and abscisic acid. By comparing the transcriptome of ethephon-treated and control plants, we found that 16 <italic>CmoAP2/ERFs</italic> were significantly upregulated after ethephon treatment. Furthermore, we determined the expression patterns of these genes at different developmental stages of female and male flowers. This study provides insights into the identification, classification, physicochemical property, phylogenetic analysis, chromosomal location, gene structure, motif identification, and CRE prediction of the AP2/ERF superfamily in <italic>C. moschata</italic>. Sixteen <italic>CmoAP2/ERF</italic> genes were identified as ethylene-inducible genes. The results of this study will be valuable for understanding the roles of <italic>CmoAP2/ERFs</italic> in ethylene response and should provide a foundation for elucidating the function of AP2/ERF TFs in <italic>C. moschata</italic>.</p>