Characterization of the CCT family and analysis of gene expression in Aegilops tauschii

Abstract

Flowering is crucial for reproductive success in flowering plant. The CCT domain-containing genes widely participate in the regulation of flowering process in various plant species. So far, the CCT family in common wheat is largely unknown. Here, we characterized the structure, organization, molecular evolution and expression of the CCT genes in Aegilops tauschii, which is the D genome donor of hexaploid wheat. Twenty-six CCT genes (AetCCT) were identified from the full genome of A. tauschii and these genes were distributed on all 7 chromosomes. Phylogenetic analysis classified these AetCCT genes into 10 subgroups. Thirteen AetCCT members in group A, C, H and G achieved rapid evolution based on evolutionary rate analysis. The AetCCT genes respond to different exogenous hormones and abiotic treatments, the expression of AetCCT4, 7, 8, 11, 12, 16, 17, 19, 21 and 22 showed a significant 24 h rhythm. This study may provide a reference for common wheat's evolution, domestication and evolvement rules, and also help us to understand the ecological adaptability of A. tauschii.

Comparative Analysis of Genomic and Transcriptome Sequences Reveals Divergent Patterns of Codon Bias in Wheat and Its Ancestor Species

“…Previous studies showed that the rapid evolution of the CCT gene family promotes the adaptability of Ae. tauschii ( Zheng et al, 2017 ), the similar codon usage bias implies that CCT genes from T. aestivum maintained the functions from its D progenitor, Ae. tauschii , presumably to enhance environment adaptability.…”

“…tauschii ), and SRR9647023 ( T. aestivum ). In addition, the sequences of genes for grain size (GS; Li and Yang, 2017 ), the CCT gene family ( Zheng et al, 2017 ), and the prolamin genes ( Ling et al, 2018 ) identified from previous studies were used. The collected fasta sequences of genes from different families were aligned to the local protein database of other species using BALSTX, which was downloaded from URGI database 3 with the expected value ( E -value) of the lowest.…”

Understanding Past, and Predicting Future, Niche Transitions based on Grass Flowering Time Variation

“…In addition to VRN2/GHD7, CO/HD1, and PRR37/PPD-H1, grasses have several other CCTdomain genes, many of which are also demonstrated players in the flowering-time pathway (Zhang et al, 2015;Zheng et al, 2017). For example, barley has nine CCT-domain genes, of which at least four (HvCO1, HvCO2, PPD-H1, and VRN-H2) are upregulated under long days and one is responsive to short days (HvCO9).…”

Comparative transcriptomics of sevenImpatiensspecies

“…Most CCT genes regulate flowering and they are studied mainly on rice for agricultural reasons (106) but studies on Aegilops tauschii proposed that CCT genes play important role in adaption of A. tauschii to the photoperiods of different regions. Zheng et al (107) identified rapid evolution of CCT genes. More gene variations are available for adaption to environmental changes, so positive selection has kept more convenient variations.…”