| Summary: | 碩士 === 國立高雄大學 === 生物科技研究所 === 99 === Crassulacean acid metabolism (CAM) is one of three major models of carbon dioxide assimilation pathway with better water-use efficiency and slower photosynthetic efficiency in photosynthesis. Previous studies indicate that expressing gene of sweet pepper plant ferredoxin-like protein (PFLP) can enhance disease resistance to bacterial pathogens. The protein sequence of PFLP shows high homology to the ferredoxin-1(Fd-1) family that belongs to photosynthetic type Fd and involves in photosystem I. It is proposed that overexpressing pflp in transgenic plant may enhance photosynthetic efficiency. To investigate whether PFLP could improve photosynthetic efficiency, pflp transgenic Phalaenopsis were generated to analyze photosynthetic markers. Transgenic plant exhibited highly electron transport rate than that of wild type (WT). Compared with WT, transgenic plant showed higher CO2 assimilation rate and organic acids contents. Both of phosphoenolpyruvate carboxylase (PEPC) and NAD+-linked malic enzyme (NAD+-ME) activities also increased in transgenic plant. Finally, the photosynthesis products were examined between transgenic plant and WT. Soluble sugars contents such as glucose, fructose, and sucrose showed significantly increased in transgenic plant. The starch grains also highly accumulated in transgenic plant than that of WT. These above results indicate that overexpressing pflp in transgenic plant increases carbohydrates accumulation by the stimulation of electron transport flow. Altogether, we suggest pflp may be an extremely useful gene for agriculture that not only increases disease resistant but also enhances photosynthetic efficiency.
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