<scp>MATE</scp> transporter <scp>DTX44</scp> is involved in regulating flowering time in <i>Arabidopsis</i>

The precise timing of flowering is crucial for the transition from vegetative to reproductive phases and is regulated by both endogenous and exogenous signals. Here, we demonstrate that DTX44, a member of the multidrug and toxic compound extrusion (MATE) transporter family, plays a role in facilitating flowering in Arabidopsis thaliana. Overexpressing of DTX44 resulted in early flowering, while a dtx44 mutant exhibited delayed flowering. The early-flowering phenotype induced by DTX44 overexpression was repressed by the ft (FLOWERING LOCUS T) mutant. In contrast, the delayed flowering phenotype of dtx44 mutants was suppressed by the flc (FLOWERING LOCUS C) mutant. Subcellular localization analysis of GFP-DTX44 in the Arabidopsis protoplasts and Nicotiana benthamiana leaves suggests that DTX44 localizes to the endoplasmic reticulum. GUS staining of the DTX44pro:DTX44-GUS transgenic plants indicated that the DTX44 gene is widely expressed in the shoots and roots. The grafting experiments between the dtx44 mutant or DTX44 overexpression lines and wild type suggested that DTX44 expression in the shoots and roots contribute to flowering time. RNA-seq analysis of dtx44 mutant and wild-type seedlings suggests that DTX44 is involved in the biosynthesis or signaling of multiple hormones in response to abiotic stresses. In summary, our study reveals the biological function of the MATE transporter DTX44 in Arabidopsis flowering. The substrate of DTX44 remains to be elucidated in future studies.