外源褪黑素对金线兰有效成分含量及抗氧化酶活性的影响

Effects of exogenous melatonin on active components content and antioxidase activity of Anoectochilus roxburghii

金线兰[Anoectochilus roxburghii(Wall.)Lindl.]是一种珍稀的兰科开唇兰属多年生单子叶草本植物,具有重要的药用价值。褪黑素(MT)是一类胺类激素,具有调节机体昼夜规律和机体抗氧化等多种生理功能。试验分别采用5μmol·L^(-1)、500μmol·L^(-1)、5 mmol·L^(-1)褪黑素根灌处理,研究褪黑素对金线兰生长发育和有效成分含量的影响,结果表明,5μmol·L^(-1)的褪黑素根灌技术处理能够显著增加总黄酮和总氨基酸的含量,分别增加了27.27%和21.79%,而500μmol·L^(-1)和5 mmol·L^(-1)褪黑素显著增加了多糖的含量,分别增加了20.79%和23.88%。3种浓度褪黑素处理下,叶绿素总含量显著高于对照41.56%~55.84%。5μmol·L^(-1)褪黑素处理下,叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性显著增加了23.72%、180.00%和33.65%。综上,褪黑素通过影响金线兰叶绿素含量、代谢物积累和抗氧化酶活性,从而增强金线兰的抗逆性,进而增强金线兰移栽后的生命力。

Anoectochilus roxburghii(Wall.) Lindl. is a rare perennial monocot herb in the family Orchidaceae, of important medicinal value. Melatonin(MT) is a class of amine hormones with various physiological functions such as regulating body day and night and antioxidant. In order to investigate the role of melatonin in the process of tissue culture seedling transplanting to the substrate, melatonin with 5 μmol·L^(-1), 500 μmol·L^(-1)and 5 mmol·L^(-1)was used to study the effects of root irrigation on seedling growth and effective component content. The results showed that 5 μmol·L^(-1)melatonin root irrigation treatment could significantly increase the total flavonoid by 27.27% and total amino acids content by 21.79%, whereas 500 μmol·L^(-1)and 5 mmol·L^(-1)melatonin significantly increased the polysaccharide content by 20.79% and 23.88%. Under the three concentrations of melatonin, the total chlorophyll content was 41.56%-55.84% significantly higher than that of the control. Under 5 μmol·L^(-1)melatonin treatment, the activities of SOD, POD and CAT in leaves were significantly increased by 23.72%, 180.00% and 33.65%. In conclusion, melatonin could enhance the stress resistance of A.roxburghii by affecting chlorophyll content, metabolite accumulation and antioxidant enzyme activity, thus enhancing the vitality of A.roxburghii after transplanting.