Comprehensive identification and expression analysis of B-Box genes in cotton

Zhen Feng,Hengling Wei,Mengyu Li,Xu Yang,Xiaokang Fu,Shuxun Yu,Liang Ma,Hantao Wang,Jianhua Lu,Yi Li

doi:10.1186/s12864-021-07770-4

Abstract

BackgroundB-BOX (BBX) proteins are zinc-finger transcription factors with one or two BBX domains and sometimes a CCT domain. These proteins play an essential role in regulating plant growth and development, as well as in resisting abiotic stress. So far, the BBX gene family has been widely studied in other crops. However, no one has systematically studied the BBX gene in cotton.ResultsIn the present study, 17, 18, 37 and 33 BBX genes were detected in Gossypium arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively, via genome-wide identification. Phylogenetic analysis showed that all BBX genes were divided into 5 main categories. The protein motifs and exon/intron structures showed that each group of BBX genes was highly conserved. Collinearity analysis revealed that the amplification of BBX gene family in Gossypium spp. was mainly through segmental replication. Nonsynonymous (Ka)/ synonymous (Ks) substitution ratios indicated that the BBX gene family had undergone purification selection throughout the long-term natural selection process. Moreover, transcriptomic data showed that some GhBBX genes were highly expressed in floral organs. The qRT-PCR results showed that there were significant differences in GhBBX genes in leaves and shoot apexes between early-maturing materials and late-maturing materials at most periods. Yeast two-hybrid results showed that GhBBX5/GhBBX23 and GhBBX8/GhBBX26 might interact with GhFT. Transcriptome data analysis and qRT-PCR verification showed that different GhBBX genes had different biological functions in abiotic stress and phytohormone response.ConclusionsOur comprehensive analysis of BBX in G. hirsutum provided a basis for further study on the molecular role of GhBBXs in regulating flowering and cotton resistance to abiotic stress.

Highlights

B-BOX (BBX) proteins are zinc-finger transcription factors with one or two BBX domains and sometimes a CCT domain
After ensuring that the identified members contained conserved domains and deleted the repeated sequences, in total, of 17, 18, 37 and 33 putative BBX sequences were identified in G. arboreum, G. raimondii, G. hirsutum and G. barbadense, respectively, via genome-wide identification analysis
The BBXs were named according to their location on the chromosomes (Fig. 1), and the BBXs located on the scaffold fragments in G. hirsutum is named

Summary

Introduction

B-BOX (BBX) proteins are zinc-finger transcription factors with one or two BBX domains and sometimes a CCT domain. These proteins play an essential role in regulating plant growth and development, as well as in resisting abiotic stress. Zinc-finger transcription factors are a kind of vital proteins, which play essential roles in plant growth and development, as well as in response to environmental stimuli [1, 2]. BBX domains play an important role in transcriptional regulation and protein-protein interactions [3, 4]. A growing body of evidence shows that BBX proteins play a crucial role in flowering [8, 9], abiotic stress responses [10] and hormonal signaling networks[4]

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