摘要
建立了测定棉花脂肪酶(Lipase,EC 3.1.1.3.)活性的新方法,使其更灵敏和准确。研究发现该酶对不同底物脂解时的pH范围不同,以棉花本身含有油脂为底物(自解)时的最适pH为5.0;以分析纯三油酸甘油酯为底物时的最适pH为10.5。休眠的种子没有脂肪酶活性,随着种子的萌发酶活性迅速上升,到第4天达到高峰。棉花幼苗子叶、下胚轴及胚根均含有脂肪酶活性,但主要集中在子叶部位。用差示离心法将组织匀浆分为4个组分后发现,棉花脂肪酶为可溶性酶,脂质体上不具有酶活性。研究还表明脂肪酶活性与种子的成熟度呈极显著正相关,受农艺因素缩节安浸种、棉酚浓度和温度的影响。提出使用100～150mg/kg缩节安浸种(毛子)12小时,播种地温12℃或14℃,棉苗出土后气温15～18℃,可保持适度的酶活性,最有利于棉苗生长;高浓度棉酚导致脂肪酶活性降低。
A new method for determining the activity of lipase (EC 3.1.1.3. )in cotton seed was established. It was found that the pH ranges of the lipase was different acting on different substrates, the optimum pH for cotton lipase to hydrolyze oils in the cotton seeds (selfhydrolysis) was 5, 0, and the optimum pH for the lipase to hydrolyze purified trioiein was 10.5. There was no lipase activity in dormant cotton seeds. The lipase activity increased rapidly during germination and reaches its maximum on the 4th day. Lipase activity has been detected in cotyledon, plumulax anis and radicel, but mainly in cotyledon. It was classed to 4groups by differential centrifugation which showed that cotton lipase was water soluble and there was no lipase activity in lipoplast. The study also indicated that the lipase activity was positively correlated with the maturity of cotton seeds significantly and was affected by agronomical factors such as soaking seed with PIX, gossypol concentration and temperature. It was suggested that using PIX0. 01％～0. 15％ to soak cotton seed (hairy seed) for 12 hours, sowing at the soil temperature of 12℃ to 14℃ and having an air temperature of 15～18℃ after emergenceo could keep the lipase with suitable activity and was most favourable for the seedling growth; activity may decrease by high concentration of gossypol in seeds.
出处
《棉花学报》
CSCD
北大核心
1993年第2期37-44,共8页
Cotton Science
关键词
棉花
脂肪酶
种子活力
cotton. lipase (EC 3.1.1.3), seed vigor
