Overexpression of the pepper transcription factor CaPF1 in transgenic Virginia pine (Pinus Virginiana Mill.) confers multiple stress tolerance and enhances organ growth

Abstract

Transcription factors play an important role in regulating gene expression in response to stress and pathogen tolerance. We describe here that overexpression of an ERF/AP2 pepper transcription factor (CaPF1) in transgenic Virginia pine (Pinus virginiana Mill.) confers tolerance to heavy metals Cadmium, Copper, and Zinc, to heat, and to pathogens Bacillus thuringiensis and Staphylococcus epidermidis, as by the survival rate of transgenic plants and the number of decreasing pathogen cells in transgenic tissues. Measurement of antioxidant enzymes ascorbate peroxidase (APOX), glutathione reductase (GR), and superoxide dismutase (SOD) activities demonstrated that the level of the enzyme activities was higher in transgenic Virginia pine plants overexpressing the CaPF1 gene, which may protect cells from the oxidative damage caused by stresses, compared to the controls. Constitutive overexpression of CaPF1 gene enhanced organ growth by increasing organ size and cell numbers in transgenic Virginia pine plants over those in control plants.