Resistance Analysis Of Lipoxygenase Gene Lox1 Transgenic Rice To Magnaporthe Grisea

Lipoxygenase (LOX) is the key enzyme in the LOX pathway. The rice expressing vectors (sense, antisense, haipin expression vector) of Loxl were constructed to analyze the role of Lox1 in rice blast resistance. The vectors were cloned into binary vector pCAMBIA1301, and then transformed into rice by Agrobacterium tumefaciens-mediated transformation. As a result, Lox1 transgenic rice plants were obtained. The present study was carried out to analyze the role of Lox1 in rice blast resistance using screened out Lox1 transgenic rice plants as study object.HygromycinB resistance analysis of the seed of transgenic T₀ and T₁ generation plants, results showed transgenic lines had HygromycinB resistance, and most of transgenic lines were inserted one site with one T-DNA. 135 lines of T₁ and T₂ generation Lox1 transgenic rice with three expressing vectors were used to analyze rice blast resistance. 62 of transgenic expressing sense mRNA (IS) lines were inoculated blast race 007( a virulence race to transgenic donor Aichiasahi), Results showed there were 12 of 1S lines altered in rice blast resistance from S (susceptible) to R (resistance) in T₁ and T₂ generation , there were 1 of 1S line altered only in T₁ generation and 28 of 1S lines altered only in T₂ generation. 30 of transgenic lines expressing antisense mRNA (1A) lines were inoculated blast race 131 (an avirulence race to transgnic donor Aichiasahi). Results showed there were 14 of 1A lines altered in rice blast resistance from R (resistance) to S (susceptible) in T₁ and T₂ generation, there were 7 of 1A lines altered only in T₁ generation and 1 of 1A line altered only in T₂ generation. 43 of transgenic lines expressing hairpin mRNA (1H) lines were also inoculated blast race 131. Results showed there were 6 of 1H lines altered in rice blast resistance from R (resistance) to S (susceptible) in T₁ and T2 generation, there were 13 of 1H lines altered only in T₁ generation and there were 2 of 1H lines altered only in T₂ generation.these results proved blast resistance of transgenic rice is hereditary. Genomic Southern blotting indicated that T-DNA insertion activity of 9 1S lines and 5 of 1A lines and 5 of 1H lines selected was independence.These indicated rice blast resistance is because of transfered Lox1 gene reaction. All of these results proved Lipoxygenase is important in in the LOX pathway and the LOX pathway has defence function in rice blast resistance. It is useful to study Lipoxygenases function and plant resistance engineering.