The Effect of Environmental Sulfate and Selenate to the Biosynthesis of Organic Sulfhydryl Compounds in Plant (I)

• Main Authors: Hung Yi Ling, 洪意玲
• Other Authors: 陳漢恆
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/46838006320121124056

碩士 === 中國文化大學 === 應用化學研究所 === 91 === The effects of different concentrations (0, 0.05, 0.1 and 0.2M) of Na2SO4 and Na2SeO4 solutions on the levels of total sulfhydryl (T-SH), water soluble sulfhydryl (W-SH) and protein sulfhydryl (P-SH) of leaves, stems and roots of spinach were investigated, respectively. The spinach were cultivated for 24hrs by water and at different concentrations of Na2SO4 and Na2SeO4 solutions, respectively. In general, the levels of sulfhydryl compounds increase with the levels of sulfate concentrations. The levels of leaf sulfhydryl compounds after 0.1 and 0.2M Na2SO4 treatments were 48.3 and 65.1% higher than the corresponding levels of 0.05M Na2SO4 treatment, respectively. The levels of stem and root sulfhydryl compounds after 0.1 and 0.2M Na2SO4 treatments were 16.7 and 42% and 46.3 and 77.1% higher than the corresponding levels of 0.05M Na2SO4, respectively. On the contrary, the levels of sulfhydryl compounds decrease with the levels of selenate concentrations. The levels of leaf sulfhydryl compounds after 0.1 and 0.2M Na2SeO4 treatments were 2.4 and 37.3% lower than the corresponding levels of 0.05M Na2SeO4 treatments, respectively. The levels of stem and root sulfhydryl compounds after 0.1 and 0.2M Na2SeO4 treatments were 32 and 36.6% and 28.2 and 43.9% higher than the corresponding levels of 0.05M Na2SeO4, respectively. The above results showed some of enzymes in the biosynthetic pathways from sulfate anions to the sulfhydryl compounds in spinch could not distinguish between sulfate and selenate anions due to the similarity on the configurations of both anions. The enzyme(s) utilizes selenate as sulfate and thus causes the inhibition of the pathway for the biosynthesis of sulfhydryl compounds. The levels of sulfhydryl compounds after .0.05M Na2SO4 treatments in leaves, roots and stems were lower than the water treatment by 25.9, 27.8 and 7.7%, respectively . This phenomenon of decreasing levels of sulfhydryl compounds even supplied the spinach with lower concentration of Na2SO4 as compared with the corresponding level of water treatment suggest that there is an activation mechanism for the biosynthesis of sulfhydryl compounds in spinach during sulfate starvatioru. The spinach also equipped with an feedback regulation for the biosynthesis of sulfhydryl compounds in spinach when sulfate is oversupplied. The levels of sulfhydryl compounds after Na2SO4 treatments in leaves, roots and stems were decreased approximately in that order by the ratio of 8.2 : 4.3 : 1 whereas the levels of sulfhydryl compounds after Na2SeO4 treatments in leaves, roots and stems were decreased in that order by the ratio of 5.9 : 1.3 : 1.