title: Genome-wide identification and characterization of auxin response factor (ARF) family genes related to flower and fruit development in papaya (Carica papaya L.).
abstract: BACKGROUND
  Auxin and auxin signaling are involved in a series of developmental processes in plants. Auxin Response Factors (ARFs) is reported to modulate the expression of target genes by binding to auxin response elements (AuxREs) and influence the transcriptional activation of down-stream target genes. However, how ARF genes function in flower development and fruit ripening of papaya (Carica papaya L.) is largely unknown. In this study, a comprehensive characterization and expression profiling analysis of 11 C. papaya ARF (CpARF) genes was performed using the newly updated papaya reference genome data.
  
  
  RESULTS
  We analyzed CpARF expression patterns at different developmental stages. CpARF1, CpARF2, CpARF4, CpARF5, and CpARF10 showed the highest expression at the initial stage of flower development, but decreased during the following developmental stages. CpARF6 expression increased during the developmental process and reached its peak level at the final stage of flower development. The expression of CpARF1 increased significantly during the fruit ripening stages. Many AuxREs were included in the promoters of two ethylene signaling genes (CpETR1 and CpETR2) and three ethylene-synthesis-related genes (CpACS1, CpACS2, and CpACO1), suggesting that CpARFs might be involved in fruit ripening via the regulation of ethylene signaling.
  
  
  CONCLUSIONS
  Our study provided comprehensive information on ARF family in papaya, including gene structures, chromosome locations, phylogenetic relationships, and expression patterns. The involvement of CpARF gene expression changes in flower and fruit development allowed us to understand the role of ARF-mediated auxin signaling in the maturation of reproductive organs in papaya.
authors.affiliation: College of Bioscience and Technology, Hunan Agricultural University, Changsha, Hunan, 410128, China. liukaidong2001@126.com.|Life Science and Technology School, Lingnan Normal University, Zhanjiang, Guangdong, 524048, China. liukaidong2001@126.com.
authors.forename: Kaidong
authors.initials: K
authors.lastname: Liu
authors.affiliation: Life Science and Technology School, Lingnan Normal University, Zhanjiang, Guangdong, 524048, China. yuanchangchun@163.com.
authors.forename: Changchun
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Life Science and Technology School, Lingnan Normal University, Zhanjiang, Guangdong, 524048, China. lihaili2425@126.com.
authors.forename: Haili
authors.initials: H
authors.lastname: Li
authors.affiliation: College of Bioscience and Technology, Hunan Agricultural University, Changsha, Hunan, 410128, China. linwhat@163.com.
authors.forename: Wanhuang
authors.initials: W
authors.lastname: Lin
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China. yjyang@hznu.edu.cn.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China. shencj@hznu.edu.cn.
authors.forename: Chenjia
authors.initials: C
authors.lastname: Shen
authors.affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310035, China. zheng9393@163.com.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Zheng
mesh_terms: D029441:Carica / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism*; D005638:Fruit / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins