关键词: 杧果, MiETR1b, 表达分析, 不定根

Abstract: A mango ETHYLENE RESPONSE1（ETR1）gene，designated as MiETR1b，was isolated from the cotyledon of mango（Mangifera indica L.‘Zihua’）using RT-PCR and RACE. The full-length cDNA was 2 530 bp with an open reading frame of 2 220 bp，encoding a putative protein of 739 amino acids. The genomic DNA sequence of MiETR1b was 4 116 bp long with a sequence of 3 305 bp from start codon to terminator codon containing six exons and five introns. The deduced amino acids possessed conserved domains of GAF and HATPase_c superfamily. Phylogenetic tree analysis indicated that MiETR1b had the highest similarity with MiETR1 from M. indica，and had high similarity with CsERS1，DlETR1，TcERS1 and PtrETR1. Quantitative real-time PCR showed that MiETR1b expressed in proximalcut surface or distal cut surface throughout the adventitious root formation period. Meanwhile，the expression of MiETR1b in distal cut surface was significantly up-regulated within 0.25–2 days. Howeve，pre-treatment with indole-3-butyric acid（IBA）and 2,3,5-triiodobenzoic acid（TIBA）significantly down-regulated MiETR1b expression of 1 day and 6 hours，respectively. On the other hand，more ethylene produced within 0.5–1 day，while the ethylene production decreased after 4 days of culture. In conclusion，MiETR1b might play an important role during the adventitious root formation of mango cotyledon segments，which was related to ethylene production.

Key words: Mangifera indica, MiETR1b, expression analysis, adventitious root