苋菜芽生长中相关酶及抗氧化活性的变化

为探究苋菜芽生长过程中相关酶及抗氧化活性的变化。采用不同浓度的茉莉酸甲酯溶液（MeJA）培养苋菜种子,根据苋菜芽的生长情况及苋红素的含量确定最优培养浓度后,在最优浓度下培养苋菜芽,记录种子的发芽率、发芽势、发芽指数、种子活力指数。收取2、4、6、8 d的苋菜芽,对根长、全长、苋红素、总酚、过氧化氢含量和抗氧化酶活性进行测定。结果表明苋菜种子的最优培养浓度为100μmol/L。MeJA处理不利于种子萌发,并且明显抑制了苋菜芽的根长和全长。但与空白对照相比,经MeJA处理过的苋菜芽中苋红素和总酚含量显著增加,并通过提高超氧化物歧化酶（SOD）的活性来清除O₂^-,延缓过氧化物酶（POD）活性的升高、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性的降低来抑制的H₂O₂积累。本研究为提高苋菜芽中苋红素的含量提供了一种新的方法,并为苋菜芽生长过程中相关酶及抗氧化活性变化的进一步研究奠定了理论基础。 

Changes of related enzymes and antioxidant activities in the growth of amaranth bud

Changes of related enzymes and antioxidant activities in the process of amaranth growth were explored.The amaranth seeds were treated with various concentrations of MeJA and the optimal concentration was determined according to the growth of amaranth bud and the content of amaranthin. During the cultivation of amaranth bud treated with optimal concentration, the germination rate, germination energy, germination index, vigor index were investgated. Then the amaranth bud were collected regularly ( 2, 4, 6 and 8 d) for the determination of root length, overall length, amaranth content, total phenolic contents, hydrogen peroxide ( H₂ O₂) content and antioxidant enzyme activities.The results showed that 100 μmol/L MeJA treatment was not good for seed germination, which inhibited the root length and overall length significantly.However, it enhanced the contents of amaranth and total phenolic when compared to the control group.It eliminated O₂^-·by improving the activity of SOD, and it could also reduce the H₂ O₂ accumulation in amaranth bud by delaying the increase of POD activity and the decrease of CAT and APX activities.This study would provide a new method to increase the yield of natural amaranthin, and it also provides theoretical basis for the further study of changes of related enzymes and antioxidant activities in the process of amaranth growth.