大气CO_(2)浓度和气温升高对玉米灌浆期碳氮代谢的影响  

Effects of increased atmospheric CO_(2) concentration and temperature on carbon and nitrogen metabolism in maize at the grain filling stage

作　　者：王娇 李萍[1] 宗毓铮[1] 张东升 史鑫蕊 杨净 郝兴宇[1] WANG Jiao;LI Ping;ZONG Yuzheng;ZHANG Dongsheng;SHI Xinrui;YANG Jing;HAO Xingyu(College of Agriculture,Shanxi Agricultural University,Taigu 030801,China)

机构地区：[1]山西农业大学农学院,太谷030801

出　　处：《中国生态农业学报（中英文）》2023年第2期325-335,共11页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金面上项目(31871517);山西省留学人员科技活动择优资助项目(20210041);山西省基础研究计划青年科学研究项目(20210302124656)资助。

摘　　要：为探讨C_(4)作物玉米对CO_(2)浓度升高、温度升高及其交互作用的响应,本研究以玉米品种‘先玉335’为材料,利用人工控制气室设置CK(CO_(2)浓度为400μmol·mol^(-1),环境温度)、EC(CO_(2)浓度为600μmol·mol^(-1),环境温度)、ET(CO_(2)浓度为400μmol·mol^(-1),气温为环境温度+2℃)、ECT(CO_(2)浓度为600μmol·mol^(-1),气温为环境温度+2℃)4个处理,测定玉米灌浆期叶片光合生理、糖代谢、氮代谢相关指标,并在成熟后测定玉米生物量。结果表明:1)CO_(2)浓度升高条件下,玉米叶片叶绿素含量、蔗糖含量、净光合速率及蔗糖合成酶、丙酮酸激酶和α-酮戊二酸脱氢酶活性显著升高(P<0.05),但谷氨酸合成酶活性显著降低(P<0.05),地上部生物量和穗重显著升高35.8%和170.2%(P<0.05)。2)气温升高条件下,叶片净光合速率、蔗糖合成酶和丙酮酸激酶活性显著升高(P<0.05),但α-酮戊二酸脱氢酶和谷氨酸合成酶活性显著降低(P<0.05),地上部生物量、叶重、茎重和穗重显著降低37.0%、28.7%、32.3%和62.2%(P<0.05)。3)CO_(2)浓度和气温均升高条件下,叶片净光合速率和丙酮酸激酶活性显著升高(P<0.05),但叶绿素含量、α-酮戊二酸脱氢酶和谷氨酸合成酶活性显著降低(P<0.05),叶重显著降低23.4%(P<0.05)。总之,CO_(2)浓度升高可通过促进玉米叶片光合速率,增加糖代谢相关酶活性和光合代谢产物等缓解温度升高对玉米生物量的负效应;CO_(2)浓度升高、气温升高以及二者互作下玉米氮代谢受到抑制,玉米叶片受到氮素胁迫,或对玉米品质产生不利影响。Future climate change will bring considerable challenges to agricultural production and food security.Presently,research on the effects of elevated CO_(2)concentration and increased temperature on crops is mostly focused on C_(3) crops,while research on C4crops is rare.Maize is the most widely planted C_(4)crop in the world,it is of great significance to explore the response of maize to elevated CO_(2)concentration,increased temperature,and their combination to assess the impacts of future climate change on C4crops.The maize variety‘Xianyu-335’was used.Four treatments were set up in controlled chambers:CK(CO_(2)concentration 400μmol·mol^(-1),ambient temperature),EC(CO_(2)concentration 600μmol·mol^(-1),ambient temperature),ET(CO_(2)concentration 400μmol·mol-1,2℃higher than ambient temperature),and ECT(CO_(2)concentration 600μmol·mol^(-1),2℃ higher than ambient temperature).The related indices of photosynthetic physiology,glucose metabolism,and nitrogen metabolism of maize leaves were measured at the grainfilling stage,and the biomass of maize was measured after ripening.The results showed that:1)under elevated CO_(2)concentrations,the chlorophyll content,sucrose content,net photosynthetic rate,sucrose synthase activity,pyruvate kinase activity,andα-ketoglutarate dehydrogenase activity in leaves were significantly increased(P<0.05),while glutamate synthase activity was significantly decreased(P<0.05).Additionally,aboveground biomass and spike mass were significantly increased by 35.8% and 170.2%,respectively(P<0.05).2)At increased temperatures,the net photosynthetic rate,and activities of sucrose synthase and pyruvate kinase of leaves were significantly increased(P<0.05),whileα-ketoglutarate dehydrogenase and glutamate synthase activities were significantly decreased(P<0.05),and the above-ground biomass and the biomasses of leaf,stem,and spike were significantly decreased by 37.0%,28.7%,32.3%,and 62.2%,respectively(P<0.05).3)Under the combination of elevated CO_(2)concentration and increased tempe

关 键 词：CO_(2)浓度升高 气温升高 玉米 碳氮代谢 生物量 

分 类 号：S513[农业科学—作物学]