Genome-wide identification, expression patterns and functional analysis of TALE (Three Amino-Acid Loop Extension) transcription factors in Arabidopsis thaliana

Abstract

Abstract Background Members of the TALE gene family play a crucial part as transcription factors, governing flower organs development, organ morphogenesis, flower meristem organization, and the development of fruits. However, detailed genome-wide study and functional analysis of TALE transcription factors has not yet been conducted in the model plant A. thaliana. Results A total of 21 genes belonging to the A. thaliana TALE gene family was identified, separated into two subfamilies (BELL and KNOX), and analyzed using bioinformatics methods, providing a theoretical basis for functional research and application of A. thaliana TALE genes. TALE genes were found on four chromosomes in A. thaliana. The A. thaliana TALE genes exhibited structural heterogeneity. All AtTALEs possessed a BELL and a KNOX domain, along with conservative structures. The A. thaliana TALE gene family had several cis-elements in response to abiotic stress and hormones, showing that the majority of AtTALE genes were involved in A. thaliana growth and development as well as stress. The expression of TALE genes in A. thaliana was shown to be tissue-specific. RNA-seq data revealed that some TALE genes were highly expressed in response to abiotic stresses. Furthermore, a functional study of the TALE gene (knat3) showed a significant reduction in silique length, seed set and weak plant stature. We found defects in female gametophyte developmental stages, suggesting the possible role of the TALE genes in female gametophyte development. While in vitro studies of knat3 mutant pollen germination showed non-viable pollen grains (30%), indicating a putative involvement of TALE genes in male gametophyte development. Conclusion This study investigated TALE genes in A. thaliana and identified their potential role in response to abiotic stresses. The functional analysis of TALE gene (knat3) revealed its significant role in gametophyte development of A. thaliana, further studies are needed to confirm the TALE gene possible function in male and female gametophyte development.

Keywords

• Transcription factors
• Arabidopsis thaliana
• Gametophyte development
• RNA-seq and gene expression