硝酸银对‘凤丹’牡丹愈伤组织褐变过程中酚类物质及相关酶活性的影响

Effects of Silver Nitrate on Phenolics and Related Enzyme Activity in Callus Browning Process of Tree Peony(Paeonia ostii 'Feng dan')

以‘凤丹’牡丹组织培养获得的增殖幼苗为材料,在含有0～5.0mg·L-1硝酸银的初代培养基中进行培养后,通过测量总酚含量、单体酚种类及其含量的变化和相关酶活性变化,确定不同浓度的硝酸银对抑制愈伤组织褐化的作用。结果表明,培养基中加入硝酸银能明显减轻褐变,其中2.0mg·L-1的综合效果最好且对组培苗正常生长无影响;硝酸银对组培苗褐变过程中产生影响的单体酚有绿原酸、芦丁、香豆酸、对香豆酸、表儿茶素、二氢槲皮素。愈伤组织中总酚含量与褐变等级呈现极显著相关性(P<0.01),过氧化物酶(POD)活性与褐变程度呈现显著负相关(P<0.05),多酚氧化酶(PPO)活性与褐变程度呈现显著正相关(P<0.05)。

Tissue cultured plantlets of Paeonia ostii were used as materials and inoculated in the basal medium containing 0-5.0 mg·L -1 silver nitrate.By measuring the content of total phenols,types and content of free phenols and related enzyme activity,the inhibition effects of different concentrations of silver nitrate on callus browning were determined.The results showed that adding silver nitrate medium could significantly reduce browning,of which 2.0 mg·L -1 worked best and did not have side effect on the normal growth of plants.The main phenols contributing to callus browning were chlorogenic acid,rutin,coumaric acid, p -coumaric acid,epicatechin,dihydro quercetin.The correlations between total phenolic content and browning grade in callus were extremely significant （ P 〈0.01）.The activity of peroxidase （POD） showed a significant negative correlation with the degree of browning （ P 〈0.05） while the correlation between polyphenol oxidase （PPO） and browning grade was significant positive （ P 〈0.05）.