Identification and expression of Aux/IAA, ARF, and LBD family transcription factors in Boehmeria nivea

Abstract

Auxin controls numerous processes in plant development and auxin/indoleacetic acid (Aux/IAA), an auxin response factor (ARF), and a lateral organ boundaries domain (LBD) were considered as early auxin response transcription factors (TFs). Till now, no Aux/IAA, ARF, and LBD TFs were identified in ramie (Boehmeria nivea L. Gaud). In this study, we used Arabidopsis and mulberry sequences as query to search against the ramie transcriptome database and the searched sequences were analyzed for a full-length coding sequence. In total, we obtained 16 BnAux/IAA, 14 BnARF, and 16 BnLBD TFs on which evolutionary analysis and expression profiling were conducted. Analysis of sequence conservation revealed close evolution relationships between ramie and mulberry. Expression analysis shows these genes were actively expressed in major ramie tissues, and several were auxin responsive. The expressions of these genes were also investigated under drought and a high temperature, main abiotic stresses during ramie life cycle. We found that most genes of the three families were stress-responsive and showed distinct expression patterns under the drought and high temperature stresses.