干旱胁迫对肋果沙棘(Hippophae neurocarpa)试管苗叶片黄酮类化合物代谢的影响

Effects of drought stress on flavonoids metabolism involved in test-tube plantlets leaves of Hippophae neurocarpa

为了探讨干旱胁迫对沙棘叶片黄酮类化合物代谢的影响,以肋果沙棘试管苗为材料,研究了不同浓度PEG-6000(0%,10%,20%,30%)对叶片类黄酮积累及其合成过程中相关酶PAL、C4H和4CL活性的影响.结果显示:(1)随干旱胁迫程度的增强,总黄酮、槲皮素、山奈酚和杨梅素含量均表现为先下降后上升的趋势,20%PEG-6000胁迫下其含量最低,比对照分别下降了20.36%,12.84%,47.81%,63.22%;在不同浓度PEG-6000胁迫下异鼠李素含量与对照相比均有升高,10%PEG-6000胁迫下其含量最高,比对照升高了79.99%.(2)干旱胁迫显著影响肋果沙棘试管苗叶片PAL、C4H和4CL的活性(P<0.05).随着胁迫程度的增加,PAL活性显著升高;C4H和4CL活性呈先升高后降低的趋势,在20%PEG-6000胁迫下达到最高.(3)杨梅素、槲皮素、山奈酚及总黄酮含量均与PAL、C4H和4CL活性负相关.尽管干旱胁迫促进了相关酶的活性,但肋果沙棘试管苗叶片中总黄酮含量并没有显著变化.

Taking test‐tube plantlets of Hippophae neurocarpa as materials ,the current study is carried out to investigate the effect of drought stress on the flavonoids accumulation and activities of Enzymes . There are four drought levels ：the control（without adding PEG‐6000） ,10% PEG‐6000 ,20% PEG‐6000 , 30% PEG‐6000 . The result show that ： （1 ）With the serious of drought stress , the contents of quercetin , kaempferol , myricetin and total flavonoids contents decreased at first , and then increased , which reachs the lowest value under 20% PEG‐6000 , and the values are 20.36% ,12.84% ,47.81% , 63.22% lower than that of control , respectively . The content of isorhamnetin is increased under PEG‐6000 stress compared with control , and it reachs the highest value under 10% PEG‐6000 , and the value is 79.99% higher than that of control ;（2） A significant difference for PAL ,C4H and 4CL is found in test‐tube plantlets leaves of H.neurocarpa under the drought stress（P〈0.05） . With the serious of drought stress ,the activity of PAL is significantly increased .The activity of C4H and 4CL increased at first ,and then decreased , which reachs the highest value under 20% PEG‐6000 ; （3） Linear regression analysis shows that the contents of kaempferol ,myricetin ,the total flavonoids and the activities of PAL ,C4H , 4CL present negative correlation . Although the related enzyme activities are increased by drought stress ,the contents of total flavonoids in test‐tube plantlets leaves of H.neurocarpa is not significantly changed .