Abstract: Abstract: 【Objective】The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase I on the fruit ripening and pathogenesis-related proteins and on the biosynthesis of endogenous ethylene and storage ability of fruits. 【Method】Several gene specific fragments of tomato(Lycopersicon esculentum) were cloned, such as the 1-aminocyclopropane-1-carboxylic acid oxidase I gene(LeACO1), 1-aminocyclopropane-1-carboxylic acid oxidase III gene(LeACO3), EIN3-binding F-box 1 gene(LeEBF1), pathogenesis-related protein 1 gene(LePR1), pathogenesis-related protein 5 gene(LePR5) and pathogenesis-related protein osmotin precursor gene(LeNP24) by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato(WT) and the LeACO1 co-suppression tomatoes(V1187 and T4B),respectively. In the same time, ethylene release measurement and storage experiment of tomato fruits were carried out.【Result】The hybridization results indicated that the expression of fruit ripening-related genes ,such as LeACO3 and LeEBF1, and pathogenesis-related protein genes, such as LePR1,LePR5 and LeNP24, were reduced sharply, and the amount of ethylene release in whole independent leaves, wounded independent leaves and whole fruits decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in tomato was suppressed.【Conclusion】In the co-suppression tomatoes, the expression of fruit ripening-related genes and pathogenesis-related protein genes were restrained at the different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.

Key words: Co-suppression, LeACO1, Fruit Ripening, Pathogenesis-Related Protein