Improvement of the photosynthetic characteristics of transgenic wheat plants by transformation with the maize C4 phosphoenolpyruvate carboxylase gene.

With 7 figures and 2 tables Abstract Attempts have been made to transform C3 crops with C4 genes to improve the photosynthetic rate of C3 plants. In our study, a full-length cDNA for phosphoenolpyruvate carboxylase gene ( pepc) was isolated from Zea mays by PCR. The pepc gene was introduced into wheat plants ( Triticum aestivum) by particle bombardment transformation. The integration, transcription and expression of the pepc gene were confirmed by Southern blot, RT-PCR and Western blot analysis. Physiological studies showed that phosphoenolpyruvate carboxylase activity in the transgenic plants was 140% higher than that of the untransformed plants. The highest rate of photosynthesis in the transgenic plants was 31.95 μmol CO2/m2/s, which was 26% greater than the rate in untransformed plants. The light saturation point and carboxylation efficiency of pepc transgenic wheat were 20% and 22.57% higher, respectively, than those of untransformed wheat. As a result, the weight of seed per spike and thousand-grain weight were 0.23 g and 1.21 g higher than those of untransformed wheat. Our research will facilitate the further study of the function of the pepc gene in wheat plants. [ABSTRACT FROM AUTHOR]