Analysis of PpGLV gene family suggests that PpGLV4 peptide coordinates auxin and ethylene signaling in peach

Members of the GOLVEN (GLV) gene family encode small secreted peptides involved in important plant developmental programs, including meristem maintenance and gravitropic responses. However, research on the functions of peptide hormones has mainly focused on various model plants, and little is known about their possible roles in peach fruit. Here, we identified eight PpGLV genes and analyzed their expression patterns in peach. PpGLV family genes share some similarities with Arabidopsis GLV family genes. PpGLV4 is responsive to 1-MCP and naphthalene acetic acid treatment. To investigate the role of PpGLV4 in detail, we treated peach callus with a synthetic PpGLV4 peptide. The upregulation of auxin and ethylene biosynthesis and signal transduction pathway genes in response to these treatment and the expression patterns of PpGLV family genes suggest that PpGLV4 may be involved in the crosstalk between auxin and ethylene signaling. The comprehensive data generated in this study improve our understanding of the roles of PpGLV peptides in peach.