AUTHOR=Li Congcong , Ma Jian , Wang Genping , Li Haiquan , Wang Hailong , Wang Guoliang , Jiang Yanmiao , Liu Yanan , Liu Guiming , Liu Guoqing , Cheng Ruhong , Wang Huan , Wei Jianhua , Yao Lei 

TITLE=Exploring the SiCCT Gene Family and Its Role in Heading Date in Foxtail Millet

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.863298

DOI=10.3389/fpls.2022.863298

ISSN=1664-462X

ABSTRACT=<p>CCT transcription factors are involved in the regulation of photoperiod and abiotic stress in <italic>Arabidopsis</italic> and rice. It is not clear that how CCT gene family expand and regulate heading date in foxtail millet. In this study, we conducted a systematic analysis of the CCT gene family in foxtail millet. Thirty-nine CCT genes were identified and divided into four subfamilies based on functional motifs. Analysis showed that dispersed duplication played a predominant role in the expansion of CCT genes during evolution. Nucleotide diversity analysis suggested that genes in <italic>CONSTANS</italic> (<italic>COL</italic>)-like, <italic>CCT MOTIF FAMILY</italic> (<italic>CMF</italic>)-like, and pseudoresponse response regulator (PRR)-like subfamilies were subjected to selection. Fifteen CCT genes were colocalized with previous heading date quantitative trait loci (QTL) and genome-wide association analysis (GWAS) signals. Transgenic plants were then employed to confirm that overexpression of the CCT gene <italic>SiPRR37</italic> delayed the heading date and increased plant height. Our study first investigated the characterization and expansion of the CCT family in foxtail millet and demonstrated the role of <italic>SiPRR37</italic>. These results lay a significant foundation for further research on the function of CCT genes and provide a cue for the regulation of heading date.</p>