Overexpressing DhPEX11-like gene for enhancing stress tolerance of melon

• Main Authors: Silvi Ikawati, 何光宜
• Other Authors: Dr. Yun Fu Yen
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/3a2r9a

碩士 === 國立嘉義大學 === 生物農業科技學系碩士班 === 100 === Abstract Salt tolerance is an important trait that is required to cope with plant productivity reduction caused by salinity. DhPEX11-like gene is a salt induced gene in Debaryomyces hansenii and overexpression of the DhPEX11-like gene in D. hansenii and salt-sensitive yeasts had lead to enhanced tolerance to salt. However, the function of DhPEX11-like gene in higher plants has not been reported so far. This investigation was aimed to overexpress this gene in melon to enhance its salt tolerance and to know the effectivity of genetic transformation by electroporation via the pollen-mediated method in melon with DhPEX11-like. The CaMV 35S promoter/DhPEX11-like gene was harboured in the plasmid pCAMBIA1380 by Recombinant PCR and then was delivered to melon plants by electroporation via the pollen-mediated method. Molecular analyses (PCR and ELISA) were used to confirm gene integration and expression. Transformed melon plants were examined to assess if they have enhanced growth ability under stress condition. Delayed development, damage symptom or biomass production were used as indicators of evaluation of stress tolerance enhancement. The results of this experiment indicate that DhPEX11-like gene could be tintroduced into melon plants by electroporation via pollen-mediated method. In comparing co-integration frequencies and stress tolerance level of DhPEX11-like gene, there was no significant difference between DNA types of supercoiled plasmid DNA, linear plasmid DNA, and T-DNA on genetic transformation of melon. The DhPEX11-like transformed plants exhibited improved biomass production at vegetative growth stage and seed germination rates under salinity stress. Plants having the higher expression level of DhPEX11-like protein showed the better tolerance ability to salinity stress. In conclusion, overexpression of DhPEX11-like gene in melon holds considerable potential for crop improvement toward enhanced stress tolerance. The discovery of the role DhPEX11-like gene in higher plants to enhance stress tolerance should make an important contribution to our better understanding about the function of the DhPEX11-like gene and help produce stress tolerant crops.