干旱胁迫对防风叶片保护酶活性、渗透调节物质含量及药材品质的影响

摘要

【目的】探讨干旱条件下防风Saposhnikovia divaricata保护酶系统与防风适应干旱的生理机制。【方法】以1年生防风为材料，设置3个梯度的水分供给，包括充分供水对照（ CK）、轻度干旱胁迫（ LD）和重度干旱胁迫（ SD）处理，研究干旱胁迫对防风叶片保护酶活性、渗透调节物质含量及2种色原酮（升麻素苷和5－O－甲基维斯阿米醇苷）总含量的影响。【结果】试验初期，不同处理下超氧化物歧化酶（ SOD）、过氧化物酶（ POD）、过氧化氢酶（ CAT）活性和脯氨酸含量均呈增加趋势，在中期达到最高值后开始呈现下降趋势。不同处理下丙二醛含量在整个试验期持续上升。试验初期，各处理2种色原酮总含量均迅速增加， LD和SD处理在试验中期达到峰值，随后开始下降，而CK处理在试验中期和后期平缓上升。 LD和SD处理的3种酶活性、渗透调节物质含量及2种色原酮总含量变化幅度大于CK，且LD和SD处理各项指标的峰值均大于CK的相应数值。各水分处理下CAT活性、2种色原酮总含量分别与SOD活性显著相关。【结论】在防风栽培过程中，适当施加干旱胁迫可促进叶片保护酶活性、渗透调节物质含量的提高，有利于防风植株健壮生长并最终提高2种色原酮的含量。%[Objective] To investigate the physiological mechanisms of drought adaptation and protective enzyme system of Saposhnikovia divaricata under drought stress.[Method] Three levels of water supply including full irrigation ( CK) , light drought stress( LD) and severe drought stress ( SD) treatments were set up for annual S.divaricata.Effects of drought stress on leaf protective enzyme activities, contents of osmoregulation substances and total content of two chromones ( prim-O-glucosylcimifugin and 5-O-methyl-visammioside) of S.divaricata were studied.[Result]The activities of superoxyde dismutase ( SOD) , peroxidase ( POD) , catalase ( CAT) , and proline content under different water treatments increased dur-ing early test stage,reached peak during middle stage and then decreased.Malondialdehyde ( MDA) con-tent under different water treatments increased throughout the entire test period.The total contents of two chromones under different water treatments all increased at early stage, reached peak during middle stage and then decreased for LD and SD treatments, while slowly increased during both middle and late stage for CK treatment.Changes in the activities of SOD, POD and CAT, the contents of osmoregulation sub-stances, and the total contents of two chromones for LD and SD treatments were higher compared to CK, and the peak values of these measurements for LD and SD treatments were also higher compared to CK. There were significant correlations between CAT activity, the total content of two chromones and SOD activity under different water treatments.[Conclusion]Appropriately imposing drought stress in the culti-vation of S.divaricata can increase protective enzyme activities and the contents of osmoregulation sub-stances of S.divaricata leaves, which is beneficial for S.divaricata growth and can increase the total content of two chromones.