Cloning and sequences analysis of 2 S-RNase genes in apricot cultivars belonging to the Central Asian ecotype group

【Objective】To clone the full length sequence of S-RNase genes involving self-incompatibilityin the Central Asian apricots and laid a foundation for the improvement of apricot self-incompatibility bymolecular biology methods.【Methods】The two apricots cultivar‘Suogejianali'and‘Saimaiti'in Xinji-ang province were tested in this article. The S-RNase gene c DNA fragment was obtained by RT-PCRtechnology and the full length sequence was obtained by RACE technology. And then using Protparamand MEGA 5.0 software to analyze the characteristics of putative proteins from two genes and constructphylogenetic tree,respectively.【Results】Two full length DNA and c DNA of S₅₂-RNase gene(KF951503)and a new S₅₃-RNase gene(KF975455)were cloned. The full length DNA of S₅₂-RNase was 2 200 bp andthe full length c DNA was 765 bp which contained an ORF(open reading frame)of 681 bp and encoded aprotein of 226 amino acids. The full length DNA of S₅₃-RNase was 1 664 bp and the full length c DNA was907 bp which contained an ORF of 732 bp and encoded a protein of 242 amino acids. It is predicted thatboth of the two genes had the RNase-T2 motif and belonging to RNase-T2 subfamily by BLASTP. Thepredicted molecular weight was 26.5 ku and 27.5 ku,and isoelectric point was 9.36 and 9.03,respective-ly,by Protparam. Both of the two RNase were hydrophilic proteins. The phylogenetic analysis indicated that the phylogenetic relationship of S₅₂ and Prunus salicina(S₇),S₅₃ and Prunus speciosa(S₁₃)were clos-est. S₅₂ and S₅₃lay different branch and possessing high polymorphism.【Conclusion】Two full length se-quence of S-RNase genes involving self-incompatibility in the Central Asian apricots were obtained.