农业环境科学学报2025，Vol.44Issue(10)：2508-2516,9.DOI:10.11654/jaes.2024-1005
大豆叶片光合氮利用效率与氮分配对水分的响应
Response of photosynthetic nitrogen use efficiency and nitrogen partitioning to water conditions in soybean leaves
摘要
Abstract
Photosynthetic nitrogen use efficiency(PNUE),a key parameter in leaf economic spectrum theory,is a critical indicator for understanding the trade-off strategies between nutrient utilization and stress adaptation in crops under resource-limited environments.To investigate the mechanistic links between PNUE and nitrogen allocation in soybean leaves under progressive water deficit,we implemented a field experiment with five water regimes:full irrigation throughout growth cycle(CK);mild drought during entire growth period(W1T1);moderate drought during entire growth period(W2T1);adequate irrigation at seedling stage+moderate drought from flowering to maturity(W2T2);adequate irrigation at seedling and flowering stages+moderate drought at maturity(W2T3).Key photosynthetic parameters including light-saturated net photosynthetic rate(Amax'),nitrogen content per unit leaf area(Narea).CO2 diffusion conductance(stomatal conductance,gs;mesophyll conductance,gm),and nitrogen allocation proportions(Rubisco-associated nitrogen proportion,PR;bioenergetics components nitrogen allocation proportion,PB;light-harvesting complex nitrogen proportion,PL)were systematically quantified.Significantly,the W2T1 treatment showed reductions of 32.2％in PNUE,42.6％in Amax',and 11.9％in Narea compared to CK(P＜0.05).Water deficit significantly impaired stomatal functionality,with gs in W2T1 and W2T3 decreasing to 56.0％and 52.0％of CK values,respectively.Concurrent reductions in gm were observed(60.9％and 78.3％of CK for W2T1 and W2T3),while a robust positive correlation emerged between gs and PNUE(P＜0.01).Chlorophyll content(cchl)demonstrated progressive depletion under water stress,peaking at 25.6％reduction in W2T1(P＜0.05).Nitrogen allocation to photosynthetic machinery showed systematic declines,with PR and PB significantly decreasing across drought treatments(P＜0.05);all moisture treatments(W1T 1,W2T1,W2T2,W2T3)exhibited significantly reduced PL compared to CK(P＜0.05),though no significant inter-treatment differences in PL were observed.PR and PB showed significant positive correlations with PNUE(P＜0.05),indicating their crucial roles in mediating moisture-induced variations in soybean PNUE.The investigation revealed that water stress significantly decreased Amax',Narea,and PNUE in soybean leaves.Furthermore,water deficit not only impaired leaf CO2 transport capacity but also reduced chlorophyll content,while simultaneously altering nitrogen allocation patterns between photosynthetic and non-photosynthetic systems-particularly manifesting as decreased PR and PB.These findings collectively demonstrate that the observed PNUE reduction under water-limited conditions primarily stems from three interrelated factors:diminished nitrogen allocation to photosynthetic components,compromised leaf CO2 diffusion capacity,and reductions in both PR and PB.关键词
光合氮利用效率/氮分配比例/CO2扩散导度/水分Key words
photosynthetic nitrogen use efficiency/nitrogen partition ratio/CO2 diffusive conductance/moisture分类
农业科学引用本文复制引用
马晓芳,白怡菲,刘倩,张方敏..大豆叶片光合氮利用效率与氮分配对水分的响应[J].农业环境科学学报,2025,44(10):2508-2516,9.基金项目
江苏省碳达峰碳中和科技创新专项(BE2023400) （BE2023400）
江苏省研究生科研与实践创新项目(KYCX22_1161) （KYCX22_1161）
国家重点研发计划项目(2023YFF0805402)Special Fund for Carbon Peak and Carbon Neutrality Science and Technology Innovation of Jiangsu Province,China(BE2023400) （2023YFF0805402）
Postgraduate Research and Practice Innovation Program of Jiangsu Province,China(KYCX22_1161) （KYCX22_1161）
National Key Research and Development Program of China(2023YFF0805402) （2023YFF0805402）
