Cryptogein (Crypt), an elicitin secreted from Phytophthora cryptogea, was used for genetic engineering of biotic and abiotic resistance plants. We generated trans-genic tobacco plants harboring a rice phenylalanine am...Cryptogein (Crypt), an elicitin secreted from Phytophthora cryptogea, was used for genetic engineering of biotic and abiotic resistance plants. We generated trans-genic tobacco plants harboring a rice phenylalanine ammo-nia-lyase (PAL) promoter and Crypt fusion gene (PAL::Crypt) or the mutated Crypt (mutation of the lysine at the position 13 to valine) under the control CaMV35S promoter (CaMV35S::CryK13V). T2 progeny of the transgenic plants showed significantly enhanced disease resistance to patho-gens of fungal Phytophthora parasitica var nicotiana (Ppn) and Alternaria alternata, and bacterial Pseudomonas syringae pv tabaci. The amount of mRNA accumulation of Crypt and CryK13V was quite low in the transgenic lines analyzed by Northern blot, and was detected by a reverse transcription PCR method. Plants harboring PAL::Crypt construct showed faster and stronger induction of PR-1a gene after Ppn inoculation than that in the wild-type plants. The re-sults suggested that the inducible PAL promoter could rap-idly respond to pathogen attack and efficiently suppress the pathogen infection. Furthermore, the enhanced tolerance to salt stress in both of the Crypt and CryK13V expressing tobacco plants was also observed compared with that in the control plants. The constitutive expression of PR and tran-scription factor genes in the transformants was probably associated with the salt tolerance. The above observations suggested that a cross-talk between biotic and abiotic stresses existed in tobacco plants.展开更多
文摘Cryptogein (Crypt), an elicitin secreted from Phytophthora cryptogea, was used for genetic engineering of biotic and abiotic resistance plants. We generated trans-genic tobacco plants harboring a rice phenylalanine ammo-nia-lyase (PAL) promoter and Crypt fusion gene (PAL::Crypt) or the mutated Crypt (mutation of the lysine at the position 13 to valine) under the control CaMV35S promoter (CaMV35S::CryK13V). T2 progeny of the transgenic plants showed significantly enhanced disease resistance to patho-gens of fungal Phytophthora parasitica var nicotiana (Ppn) and Alternaria alternata, and bacterial Pseudomonas syringae pv tabaci. The amount of mRNA accumulation of Crypt and CryK13V was quite low in the transgenic lines analyzed by Northern blot, and was detected by a reverse transcription PCR method. Plants harboring PAL::Crypt construct showed faster and stronger induction of PR-1a gene after Ppn inoculation than that in the wild-type plants. The re-sults suggested that the inducible PAL promoter could rap-idly respond to pathogen attack and efficiently suppress the pathogen infection. Furthermore, the enhanced tolerance to salt stress in both of the Crypt and CryK13V expressing tobacco plants was also observed compared with that in the control plants. The constitutive expression of PR and tran-scription factor genes in the transformants was probably associated with the salt tolerance. The above observations suggested that a cross-talk between biotic and abiotic stresses existed in tobacco plants.
