Excavation Of Sunflower NBS Resistance Gene And Its Expression Analysis In The Process Of Rust Infection

Bioinformatics analysis of NBS(Nucleotide binding site)type disease resistance genes contained in the whole genome of Helianthus annuus was performed,including prediction of gene family,phylogenetic tree,codon preference,and etc.Deep understanding of the basic physicochemical properties and chromosome localization of NBS-LRR-type genes,seeking rust-resistant related genes can provide reference for rust-resistant breeding.1.The sunflower genome encodes a total of 255 NBS genes.The subfamily is rich in types and is divided into 13 classes according to the coding structure.As a research focus,there are 42 NBS-LRR genes,including TNL,CNL and NL,which widely distribute on the 9 chromosomes of sunflower.2.The sunflower NBS type disease resistance gene uses A/T(U)to end with a codon more than the G/C,and the ENC average is 51.40.The overall preference is weak but the third base prefers to use A/T(U)at the end.By the synonymous codon usage frequency analysis,the third codon ending in A and T account for the highest proportion of codons(RSCU>1).The ENC-GC3s profile indicates that base mutations are a key factor influencing codon preference.At the same time,the correlation analysis also showed that the ENC value has a extremely significant negative correlation with the size of A3s and T3s.A variety of different analyses confirmed that the sunflower NBS type disease resistance gene sequence prefers A/T(U)-terminated codons.3.The expression of 10 genes were analyzed by Real-time PCR.The results showed the expression of 8 genes in the resistant variety was significantly higher than the susceptible one,which proves that these 8 genes play an important role in the rust resistant response.This study used bioinformatics methods to seek sunflower NBS-type disease resistance genes with several software and procedures,providing technical support and theoretical assistance for identification of disease resistance genes and resistance breeding.