硒萌爆處理對苦瓜種子穀胱 過氧化之影響

Abstract

硒為穀胱過氧化中組成物質，已知在萌爆處理過程中添加硒，可以提升種子內穀胱過氧化的活性。本試驗將月華苦瓜種子進行萌爆處理及硒萌爆處理，並於萌爆處理過程中取樣，測量苦瓜種子於浸潤及回乾過程，穀胱過氧化及其相關抗氧化物的變化情形。試驗結果顯示硒萌爆處理在浸潤時期可提高胚軸穀胱過氧化的活性，亦可提高種子內穀胱的含量。為進一步驗證硒對穀胱過氧化影響，本研究根據其他物種設計合適引子，選殖苦瓜種子中穀胱過氧化基因以觀察基因表現。本試驗所選殖之GPX300—6經比對後，與其他物種發表之穀胱過氧化有高度相似性。經南方轉漬顯示GPX在苦瓜基因組中為單套基因。而後根據定序結果，設計專一引子，分析GPX在萌爆處理期間表現，發現GPX於萌爆處理及硒萌爆處理種子中皆有表現，且在回乾時期表現最高。

Selenium is a constitute of glutathione peroxidase (GPX). It is kown that priming the seeds with selenium solution enhances the activity of seed's GPX. In the study, bitter gourd seeds (cv. Moon Shine) were primed with water or 5 ppm selenium solution, the activities of GPX and antioxidants were determined during hydration and redrying period. The results indicated that the embryo axis GPX activity was enhanced by selenium priming. Additionally selenium priming was increase the glutathione contents of treated seeds. For further examing the effect of selenium on the expression of GPX, we designed a degenerate primer to clone the GPX genes of bitter gourd seeds. The nucleotide sequence of cloned GPX300-6 matched to the GPX of other published species using NCBI Blast analysis. Genomic southern analysis showed that the GPX300-6 exits a single copy gene in Moon Shine bitter gourd seed. According to the nucleotide sequence of GPX, we designed the specific primer of GPX, and using PCR strategy to analyse the expression of GPX during priming. And it appears that GPX was expressing during both priming treatments. The expression of GPX was higher in the stage of desiccation, as compared with the GPX expressed at hydration.