Transformed EuCHIT1 Gene in Wheat (Triticum aestivum) Enhances Resistance to Stripe Rust (Puccinia striiformis f.sp tritici)
Stripe rust (Puccinia striiformis f.sp tritici) is a severe fungal disease in wheat (Triticum aestivum) that results in decreased yield and quality.It is important to explore a new way of improving stripe rust resistance with introducing exogenous resistance genes in wheat breeding.In this work,the Agrobacteriummediated transformation method was adopted to introduce eucommia ulmoides chitinasel (EuCHIT1) gene into wheat variety'Guizi 3',and T1 trangenic plants were obtained according to the result of β-glucuronidase (GUS)histochemical staining and PCR identification.The chitinase activities in the transgenic wheat plants and wildtype were measured,and the resistance to stripe rust,and protective enzymes activities and relative expression level of pathogenesis-related protein genes were measured.The results indicated that chitinase activity in the transgenic plants,3 328.63 U/g FW,was 42.21％ which was higher than that in the wild-type.After inoculating with race CYR32 for 7 d,the catalase (CAT),super-oxide dismutase (SOD) and peroxidase (POD) activities were 211.91,448.37 and 81.30 U/g FW in the transgenic plants and 159.95,294.38 and 37.87 U/g FW in the wild-type plants,respectively.This showed that the CAT,SOD and POD activities in the transgenic wheats were 32.48％,49.76％,and 114.68％,respectively,which were higher than those in the wild-type.The results also indicated that the malondialdehyde (MDA) content in the transgenic plants was 8.69 nmol/g FW which was 29.23％ lower than that in the wild-type plants (12.28 nmol/g FW).After inoculating with the fungus,the transgenic plants delayed the occurrance of stripe rust disease for 9 d compared to the wild-type.The identification of the resistance to stripe rust on wheat leaves at 14 days after inoculating showed that the transgenic plants appeared high resistance,while the wild-type was moderately susceptibel.Additionally,the lengths of flag leaves with diseases in the transgenic wheats were shorter than those in the wild-type.The relative expression levels of pathogenesis-related proteinl gene (PR-1),pathogenesis-related protein2 gene (PR-2) and pathogenesis-related protein5 gene (PR-5) in the transgenic plants were respectively 1.14,6.61 and 3.87 folds higher than those in the wild-type before inoculation of the pathogen.After inoculation with the fungus,the expression levels of PR-1,PR-2 and PR-5 in the transgenic plants were up-regulated and were 2.14,3.41 and 7.55 folds higher than the wild-type,respectively.The results suggested that transgenic plants increased protective enzymes activities and relative expression level of pathogenesis-related protein genes,which thereby enhanced the disease resistance of transgenic plants.This study supplies the basis for the creation of transgenic stripe rust resistant wheat materials,and it also provides a theoretical basis on further investigations about the mechanism of EuCHIT1 gene.
国家科技期刊平台
NSTL
万方数据
维普
