Abstract：LeMan4 gene was cloned from tomato（Lycopersicon esculentum Mill.）‘Micro-Tom’pericarp．And a plant expression vector of antisense LeMan4 was constructed．Genetic transformation to tomato was mediated by EHA105．PCR and Southern blot test were performed according to NptⅡ sequence．Physiological tests were performed on transgenetic tomatoes．This is aimed to study the role of LeMan4 in tomato softening．The results showed that NptⅡ was integrated into tomato genome，mannanase activity of transgenetic tomatoes was inhibited less than 12.2 % of the control，and transgenetic fruits could ripen，but the firmness were higher than the control，indicating that mannanase was indeed relevant to fruit softening，but not an essential factor for fruit ripening.
