article published yes Taraka Ramji Moturu author Sravankumar Thula author Ravi Kumar Singh author Tomasz Nodzyński author Radka Svobodová Vařeková author Jiří Friml author 4159519E-F248-11E8-B48F-1D18A9856A870000-0002-8302-7596 Sibu Simon author JiFr department Polarity and subcellular dynamics in plants project Strigolactones (SLs) are a relatively recent addition to the list of plant hormones that control different aspects of plant development. SL signalling is perceived by an α/β hydrolase, DWARF 14 (D14). A close homolog of D14, KARRIKIN INSENSTIVE2 (KAI2), is involved in perception of an uncharacterized molecule called karrikin (KAR). Recent studies in Arabidopsis identified the SUPPRESSOR OF MAX2 1 (SMAX1) and SMAX1-LIKE 7 (SMXL7) to be potential SCF–MAX2 complex-mediated proteasome targets of KAI2 and D14, respectively. Genetic studies on SMXL7 and SMAX1 demonstrated distinct developmental roles for each, but very little is known about these repressors in terms of their sequence features. In this study, we performed an extensive comparative analysis of SMXLs and determined their phylogenetic and evolutionary history in the plant lineage. Our results show that SMXL family members can be sub-divided into four distinct phylogenetic clades/classes, with an ancient SMAX1. Further, we identified the clade-specific motifs that have evolved and that might act as determinants of SL-KAR signalling specificity. These specificities resulted from functional diversities among the clades. Our results suggest that a gradual co-evolution of SMXL members with their upstream receptors D14/KAI2 provided an increased specificity to both the SL perception and response in land plants. Oxford University Press2018 eng Plant SciencePhysiology 0022-0957 1460-2431 29538714 00043072700001610.1093/jxb/ery097 6992367-2378 Moturu, Taraka Ramji, Sravankumar Thula, Ravi Kumar Singh, Tomasz Nodzyński, Radka Svobodová Vařeková, Jiří Friml, and Sibu Simon. “Molecular Evolution and Diversification of the SMXL Gene Family.” <i>Journal of Experimental Botany</i>. Oxford University Press, 2018. <a href="https://doi.org/10.1093/jxb/ery097">https://doi.org/10.1093/jxb/ery097</a>. Moturu, T. R., Thula, S., Singh, R. K., Nodzyński, T., Vařeková, R. S., Friml, J., &#38; Simon, S. (2018). Molecular evolution and diversification of the SMXL gene family. <i>Journal of Experimental Botany</i>. Oxford University Press. <a href="https://doi.org/10.1093/jxb/ery097">https://doi.org/10.1093/jxb/ery097</a> Moturu, Taraka Ramji, et al. “Molecular Evolution and Diversification of the SMXL Gene Family.” <i>Journal of Experimental Botany</i>, vol. 69, no. 9, Oxford University Press, 2018, pp. 2367–78, doi:<a href="https://doi.org/10.1093/jxb/ery097">10.1093/jxb/ery097</a>. Moturu TR, Thula S, Singh RK, Nodzyński T, Vařeková RS, Friml J, Simon S. 2018. Molecular evolution and diversification of the SMXL gene family. Journal of Experimental Botany. 69(9), 2367–2378. T.R. Moturu, S. Thula, R.K. Singh, T. Nodzyński, R.S. Vařeková, J. Friml, S. Simon, Journal of Experimental Botany 69 (2018) 2367–2378. T. R. Moturu <i>et al.</i>, “Molecular evolution and diversification of the SMXL gene family,” <i>Journal of Experimental Botany</i>, vol. 69, no. 9. Oxford University Press, pp. 2367–2378, 2018. Moturu TR, Thula S, Singh RK, et al. Molecular evolution and diversification of the SMXL gene family. <i>Journal of Experimental Botany</i>. 2018;69(9):2367-2378. doi:<a href="https://doi.org/10.1093/jxb/ery097">10.1093/jxb/ery097</a> 108812022-03-18T12:43:22Z2025-04-15T07:48:01Z