CDNA-AFLP Analysis Of Wheat Leaf Rust Near-isogenic Line TcLr38

Wheat leaf rust caused by Puccinia triticina is one of the most important diseases affected the wheat production wide of the whole world. The major method to control the disease is to select wheat leaf rust resistance genes and then breeding the resistance varies. The wheat leaf rust resistance gene Lr38 was isolated from group 7 chromosome of Agropyron intermedium and it was located on 2AL of the chromosome of wheat. Lr38 shows high resistance to leaf rust disease and there was no virulent Puccinia triticina strain to Lr38 in China. Lr38 is a resistance gene conferred by major gene which will have high potential in application.The study was carried out to detect the differential expression of genes in TcLr38 inoculated with Puccinia triticina strain THTS by complementary DNA amplified fragments length polymorphism (cDNA-AFLP) analysis. The infection type of THTS to TcLr38 is "0;" while the infection type of THTS to Thatcher is "4". The main results were as follows:1. Two hundreds and twenty four pairs of primers were used to screening for cDNA-AFLP analysis. About 4300 bands were detected, the average number of bands per pair of primers amplified was 19. 30.3% polymorphic bands could be amplified by 68 primer pairs between TcLr38 and Thatcher.2. Eight different types of polymorphic bands were obtained in the experiment, and 2 types of them were the specific bands from interaction of Puccinia triticina with TcLr38. 8 of 68 pairs of primers were screened for cDNA-AFLP analysis amplified special bands. The eight pairs of primers were P-CG/M-CTC, P-AC/M-CAC, P-CA/M-CGA, P-AA/M-CTG, P-GC/M-CAC, P-AG/M-CAA and P-AG/M-GGT.3. Eight differential expression bands were gained and sequenced. Blastn analysis showed that seven of them had the homology sequences of some plants, and the nucleotides were identical to the known sequences from 83% to 100%. Blastx analysis showed that six had the homology sequences, and the amino acids were similarity to the known sequences from 59% to 92%. Five of the six were the known function genes, and the gene BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 precursor, GTPase-activating protein and receptor-like kinase might be signal transduction genes, and the receptor-like kinase maybe related with resistance or defence. But the sequence of 38-3 had not be found any homology sequences in GenBank, it maybe a new sequence.4. According to the target fragment 38-116, the 3′end of the sequence were gained, the length of the sequence was 662bp, which contained 270bp 3′UTR and 120bp poly(A), and a conservative region of the 3′end of GDA1/CD39 family protein.