摘要
大气CO_2浓度升高会显著降低粳稻植株和叶片氮浓度,从而减缓叶片净光合速率和降低产量的响应幅度。植物氮浓度在高CO_2浓度下的降低与植株氮素吸收能力密切相关,而后者受到根系大小及其活力的调控。为探索通过提高粳稻根系生长及其活力来缓解大气CO_2浓度升高对氮吸收负效应的可行性,利用CO_2生长箱和农田开放式空气CO_2浓度增高FACE(free air CO_2 enrichment)研究平台,以促根突变体ERF3及其野生型作为研究对象,评价二者根系形态指标(总根长、冠根数和扎根深度)、根系活力、氮素吸收和利用效率、各器官氮浓度、叶片净光合速率和地上部生物量对CO_2浓度升高(+200μmol?mol-1)的响应。结果表明,(1)促根突变体ERF3和野生型总根长、冠根数、扎根深度及根系生物量在高CO_2浓度下均表现为显著增加(P<0.05)。突变体ERF3根系形态指标和生物量对高CO_2浓度的响应幅度为42.3%~288.9%,较野生型高出6.4%~191.0%。(2)突变体ERF3单茎根系活力在高CO_2浓度下表现为显著(P<0.05)增加,增幅为212.1%;而野生型在高CO_2浓度下无显著变化。(3)无论是生长箱还是田间盆栽试验,突变体ERF3在高浓度CO_2下均可以更好地协调氮素的吸收和利用过程。突变体ERF3各器官的氮浓度在高浓度CO_2下并未表现出明显降低趋势;而野生型在高浓度CO_2下表现为显著降低。(4)叶片氮浓度和Rubisco含量的稳定显著提高(P<0.05)了突变体ERF3叶片的净光合速率对浓度CO_2升高的响应能力,增幅为42.8%。以上结果表明,未来育种可考虑通过提高粳稻根系生长和活力来减缓CO_2浓度升高对粳稻植株氮素吸收的负效应,从而促进水稻生长和生产。
Increased atmosphere CO2 concentration significantly reduces nitrogen concentration in organs of japonica rice,which can retard the response level of leaf net photosynthesis rate and grain yield to elevated CO2.Nitrogen concentration of plant under elevated CO2 concentration is closely correlated with nitrogen uptake which is regulated by root activity.To estimate the feasibility alleviating the negative effect of elevated CO2 on nitrogen uptake of japonica rice via enhanced root growth and activity,closed growth chamber and free air carbon-dioxide enrichment(FACE)platform were used to evaluate the effect of elevated CO2(+200μmol?mol-1)on root morphological parameters(total root length,adventitious root number and root deep),root activity,nitrogen uptake and utilization efficiency,tissue nitrogen concentration,leaf net photosynthesis rate and shoot biomass of wild type and large root mutant ERF3.The results showed that:(1)Elevated CO2 significantly(P<0.05)increased total root length,adventitious root number,root deep and root biomass in both wild type and mutant ERF3.The increased percentage of these parameters mentioned above ranged from 42.3%to 288.9%mutant ERF3 and the increased percentage of root parameters of mutant ERF3 was 6.4%~191.1%higher than that of wild type.(2)Root activity per stem of mutant ERF3 was significantly(P<0.05)increased by 212.1%under elevated CO2.However,no obvious change was observed for wild type.(3)Mutant ERF3 could coordinate the relationship between nitrogen uptake and utilization much better than wild type under increased CO2 concentration.As a result,elevated CO2 had no significant effect on the organs’nitrogen concentration in mutant ERF3,regardless in growth chamber or pots in field trial,but significantly decreased that of wild type.And(4)the stabilization of leaf nitrogen concentration and rubisco content improved the response ability of leaf net photosynthesis of mutant ERF3 to elevated CO2 by an increase of 42.8%.Therefore,crop breeding should consider enhancing japonica
作者
王伟露
袁嫚嫚
朱建国
刘钢
WANG Weilu;YUAN Manman;ZHU Jianguo;LIU Gang(State Key Laboratory of Soil and Sustainable Agriculture/Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100080,China)
出处
《生态环境学报》
CSCD
北大核心
2018年第7期1203-1210,共8页
Ecology and Environmental Sciences
基金
国家基础性研究项目(2014CB954500)
国家自然科学基金国际(地区)合作与交流项目(31261140364)
关键词
粳稻
FACE
根系活力
氮浓度
叶片净光合速率
japonica rice
FACE
root activity
nitrogen concentration
leaf net photosynthesis
