Genetic Stability and Disease Resistance Analysis of Hrpzpsta Gene in Transgenic Soybean Lines

Abstract

This experiment was carried out to evaluate genetic stability and disease resistance in transformed soybean lines with hrpZpsta gene using PCR analysis, southern blotting, real-time quantitative PCR (qRT-PCR) and to analyze the resistance against Phytophthora sojae (P. sojae) and Cercospora sojina (C. sojina) after inoculation. The results obtained using PCR and southern blotting analytical methods showed that exogenous gene functional elements were stably inherited in transgenic soybean and hrpZpsta gene was successfully integrated into the soybean genome in a single copy. Results at high-generation (T7, T8) transgenic lines of hrpZpsta revealed that their relative expression of hrpZpsta gene was the highest in leaves followed by roots, and much lower in stems, flowers, and seeds. Activity change rates of peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) showed that transgenic lines significantly enhanced receptor species. The resistance of transgenic strains T7 and T8 generations against P. sojae was significantly increased with artificial inoculation methods, and the resistance against C. sojina was increased from susceptibility to the level of resistance. Under natural conditions in the field, the response of T8 transgenic lines to C. sojina reached disease resistance level. There were no significant differences in transgenic lines and recipient variety in maturing stage, leaf shape, flower color, plant height, 100-grain weight and quality content, and the two years average yield of plots increased to 11.59% and 8.19%, which significantly higher than recipient cultivar. The current results provide data support for the release of transgenic lines.