Transgenic Plants: New Biological System or New Properties of Plant-Agrobacterium Symbiosis?

Abstract

Transgenic plants have become one of the most important subjects of inquiry in biotechnology. Disputes about possible consequences of the use of genetically modified organisms still continue. Biological status of genetically modified plants is unsettled. Common criteria for assessment of the consequences of genetic transformation are lacking. Causes for and mechanisms of unforeseen consequences of transformation remain obscure. Methods of genetic engineering of plants are based on plant-Agrobacterium interaction. Transgenic plants are regarded as super-species systems produced as a result of artificial plant-Agrobacterium symbioses. Mechanisms of interaction between the members of symbiosis are very intricate and labile. Incorporation of foreign genes into T-DNA modifies characteristics of a bacterial symbiont. As a result, interaction between the organisms changes. The systems of inherent plant immunity are activated and plant metabolism is accordingly reorganized. These changes are the main reason for unintended effects of transgenosis. The intensity of response to transformation depends on the characteristics of the inserted target gene.