STUDY ON THE CHARACTERS OF AN HARPIN-PRODUCING BACTERIA STRAIN TOLERANT TO AMMONIUM AND NITROGEN-FIXING / 微生物学通报

ABSTRACT

The ability to induce hypersensity on leaves of tomato and the stability of double-plasmid of an harpin-producing, nitrogen-fixing engineered strain E4 were tested. Hypelsensitivity-inducing experiment indicated that the time and density of hypersensitivity-induction of E4 was similar to those of DH5, the positive control of pCPP430. Although E4 took the same time to induce hypersensitivity as 308R, another positive control of pCPP430, it induced weaker hypersen- sitivity on tobacco leaves. On tomato leaves, there was no difference in time and density of hypersensitivity between E4 and 308R (pCPP430). Results revealed that the two plasmids, pCPP430 and pMC73A, were unstable in host bacteria, with the losing rate of 100% at the 48th generation. The emergence probability of bacteria with either pCPP430 or pMC73A was almost the same.