Abstract:

This study cloned calmodulin gene of Ping’ou hybrid hazelnut（Corylus heterophylla × C. avellana），and further analyzed sequence features and expression characteristics，which is helpful to understand the role of calmodulin gene in the self-incompatibility reaction in Corylus. Based on the RNA-seq data，the calmodulin gene was cloned using RACE technique in the main cultivar‘Dawei’of Ping’ou hybrid hazelnut. The bioinformatic characteristics of the ChaCaM were analyzed using online service. The expression profiles of ChaCaM in various tissues and the pistils at different time after self-incompatibility pollination were investigated by using quantitative real-time PCR（qRT-PCR）. ChaCaM was submitted to GenBank with accession number KY211037. This gene contains a 450 bp open reading frame（ORF）that encodes 149 amino acid residues. The molecular weight of ChaCaM was 16.8476 kD. Bioinformatics analysis showed that ChaCaM was an acidic stable hydrophobic protein，without transmembrane domain and signal peptide present. ChaCaM was mainly located in the cytoplasmic matrix，and it contained several phosphorylation sites and glycosylation sites. Sequence analysis showed that ChaCaM contained two EFh domains，which were similar to CaM from other species. Phylogenetic analysis showed that ChaCaM was closely related to CaM in tobacco，cocoa and radish，and affiliated to the same branch with CaM in other species. Gene expression analysis showed that ChaCaM presented tissue specific expression，especially were significantly changed in the pistils after self- incompatibility pollination. ChaCaM gene has typical characteristics of calmodulin gene，and is mainly located in the cytoplasmic matrix. It belongs to constitutive expression，which may participate in self-incompatibility regulation in Corylus.

Key words: Ping’ou hybrid hazelnut, calmodulin gene, self-incompatibility, bioinformatics analysis, expression analysis