AUTHOR=Pan Gen , Yang Xiaojuan , He Jiajia , Liu Zhenyi , Chen Fengming , Chen Jiayi 

TITLE=Comprehensive analyses of the ARF gene family in cannabis reveals their potential roles in regulating cannabidiol biosynthesis and male flower development

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1394337

DOI=10.3389/fpls.2024.1394337

ISSN=1664-462X

ABSTRACT=<sec><title>Background</title><p>Cannabidiol (CBD), as an important therapeutic property of the cannabis plants, is mainly produced in the flower organs. Auxin response factors (ARFs) are play a crucial role in flower development and secondary metabolite production. However, the specific roles of ARF gene family in cannabis remain unknown.</p></sec><sec><title>Methods</title><p>In this study, various bioinformatics analysis of <italic>CsARF</italic> genes were conducted using online website and bioinformatics, quantitative real time PCR technology was used to investigate the expression patterns of the <italic>CsARF</italic> gene family in different tissues of different cannabis varieties, and subcellular localization analysis was performed in tobacco leaf.</p></sec><sec><title>Results</title><p>In this study, 22 <italic>CsARF</italic> genes were identified and found to be unevenly distributed across 9 chromosomes of the cannabis genome. Phylogenetic analysis revealed that the ARF proteins were divided into 4 subgroups. Duplication analysis identified one pair of segmental/whole-genome duplicated <italic>CsARF</italic>, and three pairs of tandemly duplicated <italic>CsARF</italic>. Collinearity analysis revealed that two <italic>CsARF</italic> genes, <italic>CsARF4</italic> and <italic>CsARF19</italic>, were orthologous in both rice and soybean. Furthermore, subcellular localization analysis showed that <italic>CsARF2</italic> was localized in the nucleus. Tissue-specific expression analysis revealed that six genes were highly expressed in cannabis male flowers, and among these genes, 3 genes were further found to be highly expressed at different developmental stages of male flowers. Meanwhile, correlation analysis between the expression level of <italic>CsARF</italic> genes and CBD content in two cultivars ‘H8’ and ‘Y7’ showed that the expression level of <italic>CsARF13</italic> was negatively correlated with CBD content, while the expression levels of six genes were positively correlated with CBD content. In addition, most of <italic>CsARF</italic> genes were responsive to IAA treatment.</p></sec><sec><title>Conclusion</title><p>Our study laid a foundation for the further studies of CsARFs function in cannabis, and provides candidate genes for breeding varieties with high CBD yield in cannabis production.</p></sec>