Response of tobacco plants transformed with the ipt gene to elevated temperature

Abstract

Transpiration rates and the content of ABA and cytokinins were compared in wild-type tobacco (Nicotiana tabacum L.) plants and the transgenic plants carrying the ipt gene, which codes for isopentenyltransferase and is expressed after a heat-shock treatment. The heat treatment initially stimulated the transpiration rate in plants of both groups. This stimulation was followed by a decrease in the transpiration of wild-type plants, whereas the transpiration rate remained high in transgenic plants. The heat shock promoted the accumulation of cytokinins in transgenic plants but had little effect on the cytokinin content in wild-type plants. The concentration of ABA increased after the heat shock in both plant groups. The significance of elevated cytokinin content for maintaining high transpiration rates in transgenic plants is discussed.