外源糖调控玉米光合系统和活性氧代谢缓解盐胁迫  

Alleviation of the Adverse Effects of Salt Stress by Regulating Photosynthetic System and Active Oxygen Metabolism in Maize Seedlings

作　　者：赵莹[1] 杨克军[1] 赵长江[1] 李佐同[1] 王玉凤[1] 付健[1] 郭亮[1] 李文胜[1] 

机构地区：[1]黑龙江八一农垦大学农学院/黑龙江省教育厅寒地作物种质改良与栽培重点实验室,黑龙江大庆163319

出　　处：《中国农业科学》2014年第20期3962-3972,共11页Scientia Agricultura Sinica

基　　金：国家科技支撑计划(2013BAD07B01);"十二五"农村领域国家科技计划(2011BAD16B1103);黑龙江省科技厅重点科技攻关项目(GZ11B107);黑龙江省应用技术研究与开发计划(GZ13B018);教育部博士学科点博导类专项科研基金(20122305110001);黑龙江省自然科学基金(C201324);黑龙江八一农垦大学研究生创新项目(YJSCX2013-03BYND)

摘　　要：【目的】揭示外源单糖葡萄糖(Glc)和双糖蔗糖(Suc)对中性氯化钠盐胁迫玉米幼苗生长发育及其生理生化机制,以及两种类型糖在缓解玉米盐胁迫的作用效果。【方法】以自主选育的玉米品种垦玉6号为材料,在植物生长室采用1/2 Hoagland营养液培养玉米幼苗。玉米培养至两叶一心时分别采用0.5 mmol·L-1 Glc和Suc预处理3 d,以1/2 Hoagland营养液为空白对照,以等浓度甘露醇为渗透对照;然后,采用150 mmol·L-1 NaCl(1/2Hoagland营养液配制)对玉米幼苗进行盐胁迫处理4—6 d,以相应糖预处理和空白处理玉米的非盐胁迫为对照。于处理第4天取第2片全展叶进行玉米光合相关和抗氧化等各项生理生化指标测定;于处理第6天进行株高、根长和干重测定;同时于处理第2、4、6天采用Li-6400XTR光合仪测定光合参数的动态变化。【结果】与空白未处理对照相比,Glc和Suc预处理导致玉米幼苗根长、干重和叶片含水量增加,但是显著提高玉米幼苗株高,分别增高了6.39%和4.86%,并维持叶片较高的净光合速率(Pn),其它供试生理生化指标变化不显著;同时,盐胁迫可明显抑制玉米幼苗生长,盐处理6 d株高和根长降低了16.37%和12.17%,地上部及地下部干重分别降低了20.69%和25.00%。盐处理导致玉米叶片中硫代巴比妥酸反应物(TBARS)和过氧化氢(H2O2)含量显著增多,抗氧化酶的活性显著降低,叶片Pn、气孔导度(Gs)、蒸腾速率(Tr)、Hill反应活性,原初光能转换效率(Fv/Fm)、光合色素含量显著下降,其中胞间CO2浓度(Ci)随着胁迫时间的延长呈先下降后上升的趋势;重要的是,外源Glc和Suc预处理可显著促进盐胁迫下玉米幼苗生长和干物质积累,其中Glc预处理的玉米株高、根长、地上和地下干重较S处理分别增加6.12%、4.49%、15.65%、18.52%,Suc预处理分别增加7.34%、4.87%、17.39%、22.22%。外源Glc和Suc预处理能有效改善玉米幼苗的光合作用,显著[Objective]This study aims at exploring and comparing the effects of exogenous monosaccharide glucose （Glc） and disaccharides sucrose （Sue） on growth, physiological and biochemical mechanisms in maize seedlings under neutral sodium salt stress. [Method] The university bred maize （Zea Mays L.） variety Kenyu No.6 was used in this study and was cultivated in 1/2 Hoagland nutrient solution in plant growth chamber. Seedlings at two-leaf stage were pretreated by 1/2 Hoagland nutrient solution containing 0.5 mmol＇L＂t Glc, Suc and mannitol for 3 days, seedlings left in normal nutrient solution and isotonic maninitol were used as control and permeability control, respectively. Then the plants were cultured in 1/2 Hoagland solution with NaC1 concentration at 150 mmol＇Lq NaC1 for 4 days or 6 days. After 4 days of salt treatment, the full expanded 2rd leaves were used to exam physiological and biochemical indicators related to photosynthesis and antioxidant metabolism. After 6 days of salt stress treatment, maize sariaples were used for measuring plant height, root length and dry weight. The Li-6400XTR photosynthetic apparatus was applied for the determination of dynamic photosynthetic parameters on day 2, 4, and 6 of salt stress. [ Result] Compared with the control, Glc and Sue pretreatment increased root length, dry matter and leaf relative water content, significantly increased plant height by 6.39% and 4.86%, respectively, and maintained higher net photosynthetic rate （P,）. There were no significant differences in other physiological and biochemical indicators between sugar pretreatment and control. Meanwhile, salt stress significantly inhibited the gro^h of maize seedlings. The height and root length of seedlings under salt treatment for 6 days decreased by 16.37% and 12.17%, and the aboveground and underground dry weight decreased by 20.69% and 25.00%. The antioxidative enzyme activities were decreased and the degree of membrane lipid peroxidation was increased under salt treatment. In addition, s

关 键 词：玉米 葡萄糖 蔗糖 盐胁迫 光合作用 

分 类 号：S513[农业科学—作物学]