外源钙(Ca)对毛葱耐镉(Cd)胁迫能力的影响  

Effects of exogenous calcium(Ca) on tolerance of Allium cepa var.agrogarum L.to cadmium(Cd) stress

作　　者：王巧玲[1] 邹金华[1] 刘东华[1] 岳洁瑜[1] 

机构地区：[1]天津市动植物抗性重点实验室,天津师范大学,天津300387

出　　处：《生态学报》2014年第5期1165-1177,共13页Acta Ecologica Sinica

基　　金：天津市高等学校科技发展计划项目(20100606;20110603);天津市应用基础计划项目青年项目(12JCQNJC09700);天津师范大学校级基金(52XB1105;52XS1210)

摘　　要：以对环境敏感的毛葱(Allium cepa var.agrogarum L.)为材料,通过水培试验分别研究不同浓度Ca(0、0.1、1、10 mmol/L)对Cd(10μmol/L、100μmol/L和300μmol/L)胁迫下毛葱幼苗生长、叶片光合特性、体内Cd积累和矿质营养的变化,探讨Ca缓解敏感植物Cd毒害的生理生化机制。结果表明:(1)Cd显著抑制了毛葱的生长并导致其根端弯曲、发黄,叶片绿色加深;外源Ca显著削弱了Cd的毒害,缓解了其对毛葱生长的抑制;(2)Cd导致毛葱叶片光合色素含量大幅度上升却显著降低了毛葱的光合作用;外源Ca延缓了光合色素上升的速度,提高了毛葱的净光合速率、气孔导度和蒸腾速率;(3)Cd胁迫导致毛葱体内Cd含量显著增加,并造成明显的矿质营养失衡,主要表现为显著降低了毛葱根中Mg、Mn,叶中Ca、Mg、Mn、Zn等元素的含量,毛葱根中Ca、Fe、Zn,叶中Fe元素含量的显著增加,扰乱了毛葱体内矿质营养的内稳态;外源Ca削弱了毛葱对Cd的积累,减轻了Cd胁迫所造成的矿质营养失衡。因此,外源Ca能通过抑制Cd的吸收,促进叶片光合作用及气体交换速率,维持植物体的含水量、植物叶片光合色素含量及矿质营养的平衡等途径来增强毛葱对Cd胁迫的耐性。Cadmium （Cd） pollution is one of the most extensive and harmful environmental problems worldwide. Recently, coastal water pollution by Cd and other heavy metals have been becoming more serious because of continuous economic development, including mining, urban traffic, burning of fossil fuels, and production of phosphate fertilizers. Calcium （Ca） is an essential macroelement that plays a crucial role in regulating plant growth and development. Moreover, Ca has been shown to alleviate heavy metal toxicity in many plants. Allium cepa is well known and commonly used in many laboratories primarily due to its many advantages, such as low cost, short test time, ease of storage and handling, large number of roots, and large cells with excellent chromosome conditions. In the present study, this plant was chosen as the experimental material to investigate whether the application of exogenous Ca can enhance the tolerance of A. cepa var. agrogarum L. to Cd stress （ 10,100 μmol/L and 300 μmol/L）. In addition, the effects of various concentrations of exogenous Ca application （0, 0.1, 1, and 10 mmol/L） on the vegetative growth, photosynthesis characteristics, Cd accumulation, and nutrient minerals of A. cepa var. agrogarum L. under various concentrations of Cd stress （ 10 μmoL/L to 300 μmol/L） were analyzed. This study showed the following results： （ 1 ） Excess Cd significantly inhibited the growth of A. cepa var. agrogarum L., resulting in changes in morphological characteristics, such as stunted and bent root tips anddarkened green leaves, whereas exogenous Ca significantly decreased the negative effects of Cd and alleviated growth inhibition in A. cepa var. agrogarum L. （2） Cd treatment greatly increased the chlorophyll contents and significantly decreased net photosynthetic rate, stomatal conductance, and transpiration rate, whereas exogenous application of Ca markedly alleviated the increase in photosynthetic pigments and significantly increased the net photosynthetic rate, stomatal condu

关 键 词：毛葱 CD CA 胁迫 耐性 

分 类 号：Q945.78[生物学—植物学]