持续淹水对北苍术幼苗生理生化及抗氧化酶和活性成分生物合成相关基因表达的影响

Effects of Pro-longed Water Stress on Physiological and Biochemical Characteristics,Antioxidant Enzymes and Expression of Genes related to Biosynthesis of Active Ingredients of Atractylodes chinensis(DC.)Koidz Seedlings

为探究北苍术幼苗对持续淹水胁迫的生理生化和分子响应特征,以正常水分管理为对照,采用单因素完全随机试验设计,模拟持续淹水18 d和恢复正常水分管理后10 d处理条件下,北苍术幼苗在生理生化特性、根系活力及解剖结构、抗氧化酶活性及其相对表达和活性成分生物合成关键酶ACC基因的响应情况。结果表明:持续淹水2~18 d,北苍术幼苗水的相对质量分数在淹水第2,4,10,16,18天显著(P<0.05)高于对照。可溶性蛋白质量浓度、脯氨酸质量分数、丙二醛质量摩尔浓度随着淹水时间的增加呈现先升高后下降趋势,与对照呈显著差异;通气组织随着淹水时间的延长而增大;SOD,POD和CAT活性呈现先升高后下降趋势,其基因的相对表达量与对照差异显著,SOD和CAT相对表达量在淹水处理第4天达到最大值,POD相对表达量在淹水第10天达到最大值;活性成分生物合成关键酶基因ACC的相对表达水平与对照差异显著,在淹水第14天时达到最大值。恢复正常水分管理第10天时,生理生化指标、抗氧化酶活性和相关基因相对表达量均有所恢复,可溶性蛋白质量浓度、脯氨酸质量分数、丙二醛质量摩尔浓度仍与对照呈显著差异;通气组织明显缩小。北苍术幼苗通过调节渗透物质、抗氧化酶活性及相关基因表达和根系组织机构改变来适应淹水胁迫。

The physiological,biochemical,and molecular characteristics of Atractylodes chinensis(DC.)Koidz seedlings responding to pro-longed water stress were studied with normal water management as a control and a single-factor-fully-randomized experimental design under conditions of 18-day submersion and 10-day normal water management to reveal the physiological and biochemical characteristics,root activity and anatomical structure,antioxidant enzymes activity and their relative expression,and a key enzyme ACC in the biosynthesis of active ingredients of A.chinensis seedlings.The results showed that after continuous submersion for 2~18 days,the relative water content of A.chinensis seedlings was significantly higher(P<0.05)than that of the control on the 2nd,4th,10th,16th,and 18th days of submersion.The soluble protein mass concentration,proline mass fraction,and molar mass concentration of malondialdehyde significantly increased and then decreased with the increase of submerging time,which was significantly different from the control.The aerated tissue was bigger as submerging time increased.The activity of SOD,POD,and CAT significantly increased and then decreased,the relative expression characteristics of the genes differed significantly from that of the control group,the relative expression levels of SOD and CAT reached their highest values on the 4th day of submersion treatment,while the relative expression levels of POD reached their highest values on the 10th day of submersion treatment.The relative expression level of ACC,a key enzyme in the biosynthesis of active ingredients,was significantly different from the control,and reached its highest value on the 14th day of submersion.After 10 days of recovery,physiological and biochemical indicators,antioxidant enzyme activity,and relative expression levels of related genes were all restored,but there were still significant or extremely significant difference from the control group in the mass concentration of soluble protein,mass fraction of proline,and molar mass concentration of malondialdehyde.The ventilation tissue was significantly reduced.The A.chinensis seedlings were adapted to pro-longed water stress by regulating osmotic substances,antioxidant enzyme activity,related gene expression,and changes in root tissue structure.