Identification of the SERK Gene Family in Paulownia fortunei and Its Involvement in the Response to Biotic and Abiotic Stresses

Somatic embryogenesis receptor-like kinases (SERKs) are receptor-like proteins that contain leucine-rich repeats and are involved in various signaling pathways. This study identified SERK family members in the Paulownia fortunei genome and analyzed their characteristics and expression profiles using bioinformatics methods. We identified 12 SERK genes with relatively conserved gene structures and motifs that were distributed unevenly on eight Paulownia chromosomes. The gene promoters contained various cis-acting elements that regulated the expression of the PfSERK genes in response to hormones and abiotic stresses. Synteny analysis indicated that 10 segmental duplication events had occurred during evolution of the PfSERK family. The expression profile of PfSERKs in various tissues of Paulownia fortunei was detected by quantitative real-time PCR (qRT-PCR). Many PfSERK genes can respond to drought and salt stress. Combined with RNA-seq and protein interaction network, it is speculated that PfSERK3/11 may participate in the occurrence of Paulownia witches' broom (PaWB) by regulating the plant height of Paulownia.