芹菜生长及黄酮类物质积累对PEG6000胁迫的响应

Response of Growth and Flavonoids Accumulation in Celery Leaves to PEG6000 Stress

为分析干旱处理对芹菜生长和黄酮类物质积累的影响,以芹菜品种‘申芹1号’为试验材料,采用聚乙二醇(PEG6000)室内水培法模拟干旱胁迫,研究轻度干旱(10%PEG 6000处理)、重度干旱(30%PEG6000处理)胁迫下芹菜生长指标、渗透调节物质、抗氧化酶系统及黄酮类物质和相关代谢酶活性的变化。轻度干旱处理下,芹菜生物量与对照无显著差异,脯氨酸和可溶性糖含量以及抗氧化酶活性显著升高,H2O2和O2ˉ·含量与对照无显著差异;苯丙氨酸解氨酶(PAL)、查尔酮合成酶(CHS)和查尔酮异构酶(CHI)活性显著升高,黄酮类物质芹菜素和毛地黄黄酮含量相比于对照显著上升,其叶片和叶柄中芹菜素含量分别比对照高出了36.05%和40.35%,毛地黄黄酮含量分别比对照高出了34.39%和43.09%。重度干旱处理下,芹菜生物量显著低于对照,株高、地上部干重和地下部干重分别比对照降低34.47%、36.02%和59.09%,脯氨酸和可溶性糖含量与对照比差异不显著,抗氧化酶活性显著高于对照,其中CAT活性显著低于轻度干旱处理,H2O2和O2ˉ·含量显著升高;芹菜中黄酮类物质含量高于对照但不存在显著差异,CHS和CHI的酶活性显著低于轻度干旱胁迫。上述指标在叶片与叶柄的变化趋势基本一致。由此可以得出,轻度干旱(10%PEG6000处理)在保持芹菜正常生长的前提下,能够促进芹菜黄酮类化合物的积累。

The study aims to analyze the effect of drought treatment on the growth and accumulation offlavonoids in celery. The change of biomass, osmolyte, antioxidant enzyme system, key enzyme in flavonoidsmetabolize and flavonoid accumulation in celery variety‘Shenqin 1＇are studied by solution culture undermild drought（10% PEG6000 treatment） and severe drought（30% PEG6000 treatment）. In mild droughtcondition, compared with control, no significant difference in biomass and H2 O2, O2ˉ·content was observed;proline and soluble sugar content, antioxidant enzyme activity, phenylalanine ammonia lyase（PAL）, chalconesynthase（CHS） and chalcone isomerase（CHI） activity and apigenin and luteolin content increasedsignificantly. Compared with those of control, the apigenin content in leaf blade and leaf stalk was increased by36.05% and 40.35%, respectively, and luteolin content was increased by 34.39% and 43.09%, respectively.Under severe drought condition, compared with control, the biomass of celery was significantly decreased, theplant height, shoot dry weight and root dry weight reduced by 34.47%, 36.02%, 59.09%, respectively.Compared with control, no significant difference in proline and soluble sugar content was observed, H2 O2,O2ˉ·content and antioxidant enzyme activity increased remarkably（CAT activity was significantly lower thanmild drought treatment）; there was no significant increase in apigenin and luteolin content, and CHS and CHIactivity were significantly reduced compared with that under mild drought stress. The change of the indexesmentioned above was almost the same in leaf blade and leaf stalk. It is concluded that mild drought（10%PEG6000 treatment） could keep a normal growth and meanwhile promote the accumulation of flavonoids incelery.