Molecular cloning and expression under abiotic stresses and hormones of the ethylene response factor VII gene FmRAP2.12 from Fraxinus mandshurica

Abstract

RELATED TO AP2.12 (RAP2.12) is one of the Ethylene Response Factors (ERF) transcription factor and plays a key role in controlling plant root bending and responding to multiple abiotic stresses including hypoxia stress. In this study, FmRAP2.12 gene was isolated and characterized from Fraxinus mandshurica Rupr. The open reading frame (ORF) of FmRAP2.12 was 1170 bp and encoded a protein of 389 amino acids. The conserved domains, three-dimensional phylogenetic relationship of FmRAP2.12 was also investigated. Quantitative real-time (qRT-PCR) analyzed the expression of FmRAP2.12 in different tissues. The expression level of FmRAP2.12 was highest in roots followed by leaves, and lowest in male flowers. Abiotic stress and hormone signal-induced expression was established using qRT-PCR. Salt stress induced FmRAP2.12 to a double peak pattern: the first peak value was at 6 h and the second at 72 h. Drought stress also induced FmRAP2.12 to a double peak pattern: the first at 6 h and the second at 48 h. FmRAP2.12 was up-regulated after initiation of gibberellic acid (GA3) treatment, with a one peak pattern at 24 h. FmRAP2.12 may not respond to cold stress and Abscisic acid (ABA) treatment. The transient overexpression of FmRAP2.12 caused the up-expression of downstream key genes of abiotic stress response and gibberellin pathway. Our research reveals the molecular characteristic and expression patterns under abiotic stress and hormone condition of FmRAP2.12, providing support for the genetic improvement of F. mandshurica at a molecular level.