Cloning and Expression Analysis of Gene CcBBX20 in pepper
Zine finger protein plays an important regulatory role in plant growth and development,as well as abiotic stress response.BBX protein belongs to a subgroup of zinc finger proteins,and CcBBX20 gene in pepper is an important member of zinc finger protein family.To investigate the biological function of CcBBX20 in the growth and development of pepper and response to abiotic stress,the structure and function of the CcBBX20 were analyzed by using gene cloning and bioinformatic methods.Expressions of the gene in the roots and leaves of pepper seedlings under 10 types of abiotic stress treatments were analyzed by using the PepperHub database.The protein coded by CcBBX20 is an unstable hydrophobic protein and has 201 amino acids with a relative molecular mass of 23.12 kD,molecule formula of C984H1551N285O329S15 and theoretical electrical point of 5.78.Moreover,the protein has two typical Bbox-SF structural domains with no signal peptide and transmembrane domain and is mainly located in the cell nucleus.Its secondary structure is mainly composed of irregular coil(58.85%)with 22.01%of α-helix and 3.83%of β-turn.The sequence of CcBBX20 in pepper is highly similar with that of potato,tomato and eggplant.Gene expression data showed that expressions of CcBBX20 were different in the roots and leaves of pepper seedlings suffering different stresses.Treatments of abscisic acid,gibberellin,auxin,salicylic acid,methyl jasmonate and high temperature increased the expressions of CcBBX20,which reached up to the highest at temperature of 42℃for 1.5 h.However,its expressions were decreased under the treatments of hydrogen peroxide,mannitol and salinity.As a result,as a member of the BBX gene family,pepper CcBBX20 gene plays a role in response to high temperature stress,potentially improving the tolerance of seedlings to high temperature and providing a candidate gene for breeding new heat-tolerant pepper cultivars.