臭氧胁迫下外源喷施亚精胺和EDU对小麦生理指标的影响

采用开顶式气室模拟研究外源喷施亚精胺(Spd)和EDU对O3胁迫下小麦生理指标变化的影响,测定的生理指标包括丙二醛含量(MDA)、超氧化物歧化酶活性(SOD)、过氧化物酶活性(POD)、过氧化氢酶活性(CAT)、可溶性蛋白质含量、还原型谷胱甘肽含量(GSH)、谷胱甘肽还原酶活性(GR)、抗坏血酸含量(ASA)和抗坏血酸过氧化物酶活性(APX)。结果表明,外源喷施Spd和EDU可不同程度地提高小麦叶片的SOD、POD、CAT、APX和GR活性,降低MDA和ASA含量,提高GSH和可溶性蛋白含量。当Spd的浓度为0.25、0.50和0.75mmol·L-1时,小麦叶片POD活性比对照处理提高90.0%～226.7%,CAT活性提高21.4%～40.6%,APX活性提高164.2%～191.0%,MDA含量降低9.7%～42.5%。喷施300mg·L-1EDU可导致小麦叶片POD、CAT和APX活性分别比对照处理提高76.8%、27.4%和128.1%,MDA和ASA含量降低,GSH含量提高25.6%。以上结果说明Spd和EDU是2种比较有效的缓解小麦O3胁迫的抗氧化剂,可用来防护O3对小麦的毒害。

Effects of Spermidine and EDU on Physiological Indexes of Wheat under Ozone Stress

The effects of exogenous spermidine (Spd) and ethylenediurea (EDU) on active oxygen scavenging system under ozone stress was studied by open top chambers (OTCs). Some physiological indexes (malondialdehyde, MDA; soluble protein; ascorbic acid, ASA; glutathione, GSH, superoxide dismutase, SOD; peroxidase, POD; catalase, CAT; ascorbate peroxidase, APX; glutathione reductase, GR) of wheat were investigated. The results showed that both Spd and EDU improved SOD, POD, CAT, APX and GR activities, GSH and soluble protein contents, while decreased the contents of MDA and ASA. Compared to the control treatment, activities of POD, CAT and APX in wheat leaf increased 90.0-226.7%, 21.4-40.6% and 164.2-191.0%, respectively, while the contents of MDA decreased 9.7-42.5% at Spd concentrations of 0.25, 0.50 and 0.75 mmol•L-1. Compared to the control treatment, EDU concentration of 300 mg•L-1 increased POD, CAT and APX activities by 76.8%, 27.4% and 128.1%, respectively, MDA and ASA contents decreased by 17.5% and 14.9%, respectively, while the content of GSH increased 25.6%. Our results indicated that Spd and EDU are two effective antioxidants mitigating wheat O3 stress, can be used to prevent O3 poisoning.