The relationship between protein oxidation and seed aging in rice.

• Main Authors: Chen, Sheng-Long, 陳勝龍
• Other Authors: Chen Chung-Li
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/13771192704902485912

碩士 === 國立中興大學 === 農藝學研究所 === 86 === Several oxidative systems could generate reactive oxygen species and c atalyze protein oxidation in living organisms. After oxidative modification,ta rget proteins change their characters and become less active or highly sensiti veto proteolytic degradation. Levels of protein oxidation increase in size dur ing aging and in various pathological state. In order to test age-related prot einoxidation model is valid in plant, change of seed storage proteins status w as investigated during seed aging. The results are summarized as follows：1.Le vels of protein oxidative status could be detected by carbonyl reagents--- DN PH, FL-NHNH2, FLAD-NHNH2.2.BSA, G-6-PDH, and rice storage protein albumins, gl obulins, prolamins, and glutelins are oxidized by two metal-catalyzed oxidat ion systems ascorbate/ FeCl3 and FeSO4/FeCl3 in vitro. The accumulation of ox idized protein depends on the concentration of catalyzer and reaction time.Ca rbonyl contents in rice storage protein oxidized by MCO system in vitro are globulins(28 nmol/mg protein) >glutelins(22 nmol/mg protein)>albumins(14 nmol /mg protein)>prolamins(7~9 nmol/mg protein).3.Seed stored at ambient or 10℃ c ondition for more than six months resulted in a marked decline in germination and extarctable storage proteins. There was accompanied by an evident increa se in oxidized protein levels especially for albumin. Low temperature could r educe oxidized protein accumulation during storage.4.Intact seed, brown riec, milled rice, rice bran and milled rice flour stored at ambient or aging(45℃, 75% RH) condition for six months showed that storage proteins albumins,globu lins and glutelins were oxidized more rapidly in aging condition than ambien t. The speeds of protein oxidation were milled rice flour >rice bran>milled r ice>brown rice>intact seed.5.There are not any correlation between oxidized pr oteins and germination percentage in rice seeds druing storage.