外源水杨酸对盐胁迫下非洲菊抗氧化酶活性和生理特性的影响(英文)

以非洲菊(Gerbera jamesonii L.)品种Amaretto'为试材,研究外源水杨酸(SA)对缓解非洲菊生殖生长期因盐胁迫引起的过氧化伤害作用.在开花前分别用0、0.5和1.0mmol L-1SA对非洲菊植株进行预处理,3d后用100mmol L-1NaCl灌溉,持续2周;对照植株未经NaCl和SA处理.结果表明:盐胁迫处理后,叶片的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性增加,丙二醛(MDA)含量、电解质外渗率和脯氨酸含量提高;外源SA预处理显著降低了盐胁迫植株叶片的MDA含量和电解质外渗率;在外源0.5mmol L-1SA预处理后,植株SOD和POD活性分别是对照的1.4倍和2.4倍;SA预处理后与植株耐盐性相关的生理生化指标呈显著相关,以0.5mmol L-1SA处理增强植株盐胁迫耐性的效果更好.说明外源SA处理能够诱导盐胁迫下非洲菊植株的抗氧化反应,水杨酸将是一种提高园艺作物耐盐性的有效物质.

Effects of exogenous salicylic acid on antioxidative enzyme activities and physiological characteristics in gerbera (Gerbera jamesonii L) grown under NaCl stress

Ameliorative effects of exogenously applied salicylic acid (SA) on salt-induced oxidative damage in gerbera (Gerbera jamesonii L.'Amaretto') at reproductive stage were investigated.At the onset of flower initiation,plants pretreated with the foliar spraying of 0,0.5 and 1.0 mmol·L-1 SA were irrigated with 100 mmol·L-1 NaCl (three days after the SA pretreatment) and continued for two weeks.Control plants did not receive either NaCl or SA.As a response to salt stress,superoxide dismutase (SOD) and peroxidase (POD) activities,malondialdehyde (MDA) content,electrolyte leakage as well as the proline accumulation were increased.Nevertheless,SA pretreatment significantly reduced MDA content and electrolyte leakage.SOD and POD activities were significantly higher (1.4-fold and 2.4-fold,respectively) in 0.5 mmol·L-1 SA-pretreated salt-stressed plants compared to SA-unpretreated salt-stressed plants.These results indicate that exogenous SA involves,at least in part,in inducing antioxidative defense system in salt-stressed gerbera.In general,of the two concentrations tested,0.5 mmol·L-1 SA concentration seemed to have greater effect throughout the experiment.Responses of salt-stressed plants pretreated with SA and significant correlation among them,predict its future potential as a pragmatic approach to improve salt tolerance in horticultural crops.