Genome-Wide Identification and Expression Analysis of BBX Transcription Factors in Iris germanica L.

Yinjie Wang,Haiyan Yuan,Ting Zhang,Qingquan Liu,Yongxia Zhang,Xinran Chong

doi:10.3390/ijms22168793

Abstract

The family of B-box (BBX) transcription factors contains one or two B-BOX domains and sometimes also features a highly conserved CCT domain, which plays important roles in plant growth, development and stress response. Nevertheless, no systematic study of the BBX gene family in Iris germanica L. has been undertaken. In this study, a set of six BBX TF family genes from I. germanica was identified based on transcriptomic sequences, and clustered into three clades according to phylogenetic analysis. A transient expression analysis revealed that all six BBX proteins were localized in the nucleus. A yeast one-hybrid assay demonstrated that IgBBX3 has transactivational activity, while IgBBX1, IgBBX2, IgBBX4, and IgBBX5 have no transcriptional activation ability. The transcript abundance of IgBBXs in different tissues was divided into two major groups. The expression of IgBBX1, IgBBX2, IgBBX3 and IgBBX5 was higher in leaves, whereas IgBBX4 and IgBBX6 was higher in roots. The stress response patterns of six IgBBX were detected under phytohormone treatments and abiotic stresses. The results of this study lay the basis for further research on the functions of BBX gene family members in plant hormone and stress responses, which will promote their application in I. germanica breeding.

Highlights

IgBBX3, IgBBX4, and IgBBX5 consisted of two B-BOX domains without a CCT domain
The results showed six IgBBX genes were differBBX2, IgBBX3 and IgBBX5 was higher in leaves, whereas IgBBX4 and IgBBX6 was higher entially transcribed theand plant
As BBX family Transcription factors (TFs) play important roles in plant development and stress responses [3], we investigated the responses of IgBBXs to various plant hormones and abiotic stress treatments

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Transcription factors (TFs) play primary roles in gene expression regulation. According to their conserved domains, TFs can be divided into different gene families. The B-box (BBX) proteins form a class of zinc finger transcription factors containing one or two B-box domains near their N-terminus, and some members feature a highly conserved CCT (CONSTANS, CO-like, and TOC1) domain near their C-terminus [1]. In Arabidopsis, the BBX TF family has 32 members and divided into five groups according to the number of

Methods

Results

Conclusion