Abstract
The accumulated evidence reveals that the increases in citrate synthesis and exudation enhance the resistance of plants to Aluminum (Al). The carbon skeleton used for synthesis of citrate is supplied from photosynthesis. To investigate whether the increase in citrate syntheses in the leaves of plants would improve their resistance to Al, citrate synthase (CS) was overexpressed in tobacco leaves under the control of tomato rbcS-3C promoter and the overexpressed CS was localized in the cytoplasm. Overexpression of CS resulted in 1-5 fold increase in citrate synthase activity in transgenic tobacco leaves compared with wild-type plants. The staining experiments for roots showed that the transgenic tobacco lines were much more tolerance to Al than wild-type plants after exposure to 100-300 μmol Al.
