Abstract

K-homologous (KH) family is a type of nucleic acid-binding protein containing the KH domain and has been found to affect splicing and transcriptional regulation. However, KH family genes haven’t been investigated in plant species systematically. In this study, we identified 30 genes that belonged to the KH family based on HMM of the KH domain inArabidopsis thaliana. Phylogenetic tree analysis showed that the KH family is grouped into three subgroups. Synteny analysis showed thatAtKH9andAtKH29have the conserved synteny relationship betweenA. thalianaand the other five species. TheAtKH9andAtKH29were located in the cytoplasm and nucleus. The seed germination rates of the mutantsatkh9andatkh29were higher than wild-type after abscisic acid (ABA) and salicylic acid (SA) treatments. In addition, the expression of ABA-related genes, such asABRE-binding factor 2(ABF2),ABRE-binding factor 4(ABF4), anddelta 1-pyrroline-5-carboxylate synthase(P5CS), and an SA-related genepathogenesis-related proteins b(PR1b) were downregulated after ABA and SA treatments, respectively. These results suggested thatatkh9andatkh29mutants inhibit the effect of ABA and SA on seed germination. In conclusion, our results provide valuable information for further exploration of the function of KH family genes and propose directions and ideas for the identification and characterization of KH family genes in other plants.Keywords:KH family;expression;ABA and SA