铅对小麦幼苗光合特性及抗氧化酶活性的影响  

Effect of Lead Stress on Photosynthetic Characteristics and the Activity of Antioxidant Enzymes in Wheat Seedling

作　　者：韩红江[1] 田琴[1] 李维平[1] 

机构地区：[1]西北农林科技大学生命科学学院,杨凌712100

出　　处：《石河子大学学报（自然科学版）》2012年第1期18-22,共5页Journal of Shihezi University(Natural Science)

摘　　要：采用水培方法,以陕253小麦为试验材料,研究铅胁迫对幼苗光合特性及其抗氧化酶活性的影响。结果表明:随着铅浓度的增大,小麦叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、叶片光合色素含量(SPAD)均呈现先升高后降低的趋势,细胞间隙CO2浓度(Ci)则先降低后升高,且均在铅浓度为100mg/L时达到最大值或最小值。研究结果还表明,引起光合作用下降的原因是气孔因素和非气孔因素共同作用的结果。铅处理小麦幼苗后,超氧化物歧化酶(SOD)活性先升高后降低,而过氧化氢酶(CAT)和过氧化物酶(POD)的活性有所增加,当铅浓度达200、300mg/L时丙二醛(MDA)含量显著升高,说明小麦幼苗的膜系统受到了一定程度的破坏。A hydroponic experiment was carried out to investigate the effect of different Pb levels on photosynthetic characteristics and the activity of antioxidant enzymes in wheat seedlings.The results showed that,with the increase of lead concentration,the net photosynthetic rate（Pn）,transpiration rate（Tr）,both stomatal conductance（Gs） or photosynthetic pigment content（SPAD） increased firstly and dropped afterwards,while intercellular CO2 concentration（Ci） firstly dropped and increased afterwards,both reaching the maximum or minimum under 100 mg/L treatment of Pb concentration.The results also showed that decrease of photosynthesis was caused by both stomatal factors and non-stomatal factors;with the increase of lead concentration,the SOD activities increased in the beginning and then fell,while the CAT and POD activities increased all the time,the MDA content rose significantly when pb level reached 200 mg/L and 300 mg/L,which suggested that the membrane system of wheat seedling was damaged by lead stress.

关 键 词：小麦 铅胁迫 光合特性 叶绿素 抗氧化酶 

分 类 号：Q945.78[生物学—植物学]