Not essential for epidermal patterning and not redundant with STRUBBELIG. Alternative splicing was observed in all tissues. Expressed in roots, stems, leaves and flowers. Low expression in seedlings and siliques. The protein kinase domain is predicted to be catalytically inactive. Plants do not show root phenotype alteration. Over-expression of SRF1B induces no obvious phenotypes while overexpression of SRF1A may lead to seedling lethality in both cv. Landsberg and cv. Columbia. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.