Cloning and Expression of CsRAD51 Gene of Citrus suavissima ’Wuzi Ougan’

Citrus suavissima ‘Wuzi Ougan’ is a seedless bud variation of C. suavissima with male sterility and pollen abortion from the tetrad stage.RNA of C. suavissima and C. suavissima ‘Wuzi Ougan’ was extracted and the full-length cDNA was cloned and bioinformatics analysis of aminoacid sequences was conducted. The results showed that the sequence length of CsRAD51 was 1210bp, containing an ORF of 1029bp. The deducedprotein was hydrophobic one, encoded 388 amino acids. Its molecular weight was 45740.1D, with atom number of 6555 and isoelectric point of 10.20.Homologous alignment demonstrated the homology coefficient of C. suavissima ‘Wuzi Ougan’ with C. sinensis, Jatropha curcas, Elaeis guineensis,Cucumis sativus and Populus nigra was 99%，98%，98%，98%，98% respectively. The Real-time PCR results showed that the relative expression ofCsRAD51 in C. suavissima ‘Wuzi Ougan’ was significantly higher than C. suavissima at microsporocyte stage, tetrad stage and uninucleusmicrospore stage, indicating that overexpression of CsRAD51 inhibited double-strand break-induced homologous recombination and led to DNAdamage and abnormal meiosis.