Comparative Analysis of Casparian Strip Membrane Domain Protein Family in (L.) and (L.).

The Casparian strip membrane domain proteins (CASPs) are pivotal for the formation of the Casparian strip (CS) in endodermal cells and play a crucial role in a plant's response to environmental stresses. However, existing research on the gene family in rice and lacks a comprehensive bioinformatics analysis and necessitates further exploration. In this study, we identified 41 and 39 genes, which were grouped into six distinct subgroups. Collinearity analysis underscored the pivotal roles of WGD and TD events in driving the evolution of CASPs, with WGDs being the dominant force. On the one hand, the analysis of cis-elements indicated that most and genes contain MYB binding motifs. On the other hand, RNA-seq revealed that the majority of and genes are highly expressed in roots, particularly in endodermal cells, where and demonstrated the most pronounced expression. These results suggest that and might be candidate genes involved in the formation of the endodermis CS. RT-qPCR results demonstrated that may be candidate genes for the ion defect process. Collectively, this study offers a theoretical foundation for unraveling the biological functions of genes in rice and .