Genome-wide analysis of BpDof genes and the tolerance to drought stress in birch (Betula platyphylla)

Abstract

Background DNA binding with one finger (Dof) proteins are plant-specific transcription factors playing vital roles in developmental processes and stress responses in plants. Nevertheless, the characterizations, expression patterns, and functions of the Dof family under drought stress (a key determinant of plant physiology and metabolic homeostasis) in woody plants remain unclear. Methods The birch (Betula platyphylla var. mandshuric) genome and plant TFDB database were used to identify Dof gene family members in birch plants. ClustalW2 of BioEdit v7.2.1, MEGA v7.0, ExPASy ProtParam tool, Subloc, TMHMM v2.0, GSDS v2.0, MEME, TBtools, KaKs Calculator v2.0, and PlantCARE were respectively used to align the BpDof sequences, build a phylogenetic tree, identify the physicochemical properties, analyze the chromosomal distribution and synteny, and identify the cis-elements in the promoter regions of the 26 BpDof genes. Additionally, the birch seedlings were exposed to PEG6000-simulated drought stress, and the expression patterns of the BpDof genes in different tissues were analyzed by qRT-PCR. The histochemical staining and the evaluation of physiological indexes were performed to assess the plant tolerance to drought with transient overexpression of BpDof4, BpDof11, and BpDof17 genes. SPSS software and ANOVA were used to conduct all statistical analyses and determine statistically significant differences between results. Results A total of 26 BpDof genes were identified in birch via whole-genome analysis. The conserved Dof domain with a C(x)2C(x)21C(x)2C zinc finger motif was present in all BpDof proteins. These birch BpDofs were classified into four groups (A to D) according to the phylogenetic analysis of Arabidopsis thaliana Dof genes. BpDof proteins within the same group mostly possessed similar motifs, as detected by conserved motif analysis. The exon–intron analysis revealed that the structures of BpDof genes differed, indicating probable gene gain and lose during the BpDof evolution. The chromosomal distribution and synteny analysis showed that the 26 BpDofs were unevenly distributed on 14 chromosomes, and seven duplication events among six chromosomes were found. Cis-acting elements were abundant in the promoter regions of the 26 BpDof genes. qRT-PCR revealed that the expression of the 26 BpDof genes was differentially regulated by drought stress among roots, stems, and leaves. Most BpDof genes responded to drought stress, and BpDof4, BpDof11, and BpDof17­ were significantly up-regulated. Therefore, plants overexpressing these three genes were generated to investigate drought stress tolerance. The BpDof4-, BpDof11-, and BpDof17­-overexpressing plants showed promoted reactive oxygen species (ROS) scavenging capabilities and less severe cell damage, suggesting that they conferred enhanced drought tolerance in birch. This study provided an in-depth insight into the structure, evolution, expression, and function of the Dof gene family in plants.

Transcription factor ZmDof22 enhances drought tolerance by regulating stomatal movement and antioxidant enzyme activities in maize (Zea mays L.)

“…Therefore, exploring key drought-tolerance genes and creating drought-resistant germplasm is urgent. Dof is a classic protein of the zinc finger family that regulates multiple biological functions and responds to abiotic stress in plants (Sun et al 2021). Recently, the Dof family has been systematically studied at the genome-wide level in many plant species; however, the molecular mechanisms of ZmDofs in maize are poorly understood.…”

DOF transcription factors: Specific regulators of plant biological processes

“…Undoubtedly, MdDOF54 could improve the drought tolerance of plants. Similarly, overexpression of the birch BpDOF4, BpDOF11, and BpDOF17 genes improved drought tolerance by enhancing the ROS scavenging ability (Sun et al, 2021). Notably, DOF proteins can also improve plant survivability in extreme temperature environments.…”

“…Earlier studies identified 37 DOF members in Arabidopsis thaliana, one of which is a pseudogene (Yanagisawa, 2002), while 30 DOF members were identified in rice (Oryza sativa) (Lijavetzky et al, 2003). With the analysis of the whole genomes of many species, an increasing number of DOF members have been identified in different species (Table 1), including 26 DOF genes in birch (Betula platyphylla) (Sun et al, 2021), 36 in watermelon (Citrullus lanatus) (Zhou et al, 2020), 35 in foxtail millet (Setaria italica) (Zhang et al, 2017), 22 in spinach (Spinacia oleracea) (Yu et al, 2021a) and 24 in rose (Rosa chinensis) (Nan et al, 2021). Despite the species differences, the functions of DOF members in the monocot model plant rice are still questioned.…”

“…DOF (DNA binding with One Finger) is a classic protein in the ZF superfamily (Yang et al, 2022;Zhang et al, 2022). An increasing number of members of the DOF TF family have been reported to be involved in regulating plant germination (Chen et al, 2017), growth and development (Liu et al, 2022), and responses to abiotic stress (Sun et al, 2021). A recent perspective article reported that DOFs are involved in multiple hormonal pathways during abiotic stresses (Wang et al, 2022).…”

Identification of Dof transcription factors in Dendrobium huoshanense and expression pattern under abiotic stresses

“…In monocot plants, Eleusine coracana (48 individuals), Musa acuminata (74 individuals), and Setaria italica (35 individuals) had been identified ( Dong et al, 2016 ; Zhang et al, 2017 ; Gupta et al, 2018 ). In dicotyledonous plants, A. thaliana (39 individuals), i (60 individuals), Populus trichocarpa (41 individuals), and Betula platyphylla (26 individuals) had been identified ( Le Hir and Bellini, 2013 ; Wang et al, 2017 ; Zhang et al, 2017 ; Sun et al, 2021 ).…”