甘蓝型油菜苗期氮高效吸收转运特征研究  

Characteristics of Efficient Nitrogen Uptake and Transport of Rapeseed at Seedling Stage

作　　者：巢成生 王玉乾 沈欣杰[1] 代晶 顾炽明 李银水[1] 谢立华[1] 胡小加[1] 秦璐[1] 廖星[1] CHAO ChengSheng;WANG YuQian;SHEN XinJie;DAI Jing;GU ChiMing;LI YinShui;XIE LiHua;HU XiaoJia;QIN Lu;LIAO Xing(Oil Crops Research Institute,Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetics Improvement of Oil Crops,Ministry of Agriculture and Rural Affairs,Wuhan 430062)

机构地区：[1]中国农业科学院油料作物研究所/农业农村部油料作物生物学与遗传育种重点实验室,武汉430062

出　　处：《中国农业科学》2022年第6期1172-1188,I0030,共18页Scientia Agricultura Sinica

基　　金：国家绿肥产业技术体系专项(CARS-22-05);国家重点研发计划(2016YFD0100202-5);中国农业科学院科技创新工程(CAASASTIP-2013-OCRI)。

摘　　要：【目的】氮素吸收效率是影响作物氮效率的重要方面,开展油菜氮高效吸收转运特征研究旨在为提升油菜氮吸收效率及产量提供理论依据。【方法】为探究油菜氮高效吸收转运机理,以一对氮效率差异显著的油菜种质:氮高效种质‘498’和氮低效种质‘428’为试验材料,在营养液培养条件下,设置正常供氮(9.5 mmol·L^(-1))和低氮(0.475 mmol·L^(-1))处理,研究不同氮浓度下油菜在3个生长时期(物候生长期12、14和16)的生理指标差异;并运用^(15)N同位素示踪技术研究不同种质对NO_(3)^(-)和NH_(4)^(+)的吸收和转运能力。同时,利用实时荧光定量PCR技术分析氮吸收转运相关基因(BnNPFs、BnNRT2s和BnAMTs)在氮效率不同油菜种质中的表达差异。【结果】不同氮浓度处理下,油菜种质‘498’的植株生长和根系发育均表现较强优势,根系形态指标(主根长、总根长、根表面积、根体积和侧根数)、生物量、氮累积量和氮吸收效率均显著高于油菜种质‘428’。^(15)N同位素示踪试验也表明,油菜种质‘498’对NO_(3)^(-)和NH_(4)^(+)的吸收累积强于‘428’,尤其是NH_(4)^(+),‘498’在高低氮浓度处理下植株^(15)NH_(4)^(+)累积量均显著高于‘428’。实时荧光定量PCR分析结果进一步显示,在正常供氮处理下,参与NO_(3)^(-)、NH_(4)^(+)吸收与转运的基因(BnNPF6.3a、BnNRT2.1e、BnNPF7.2a、BnNPF7.2c、BnNPF6.2c、BnAMT1;2a、BnAMT1;3c、BnAMT1;4a、BnAMT2;1a和BnAMT2;1b)在‘498’中的相对表达量显著高于‘428’;而在低氮处理下,‘498’根中参与NO_(3)^(-)吸收与转运的基因(BnNRT2.4a、BnNRT2.5a和BnNRT2.5b)的相对表达量显著低于‘428’,但是参与调控NO_(3)^(-)转运及再分配的基因(BnNPF7.3a和BnNPF6.2c)表达水平较高,同时,参与NH_(4)^(+)吸收转运的基因(BnAMT1;1a、BnAMT1;2a、BnAMT1;3c、BnAMT1;4a、BnAMT2;1a和BnAMT2;1b)的表达水平也显著高于‘428’。【结论】与氮低效种质�【Objective】Nitrogen(N)uptake efficiency is one of the important factors affecting crop N efficiency,investigating characteristics of efficient N uptake and transport was the purpose to provide the theoretical basis for improving N efficiency and yield of rapeseed(Brassica napus L.)varieties.【Method】To explore the mechanisms underlying high N uptake and transport in rapeseed,two rapeseed germplasms with contrasting N efficiency(N efficient germplasm‘498’and N inefficient germplasm‘428’)were used in this study under normal N(9.5 mmol·L^(-1))and low N(0.475 mmol·L^(-1))conditions at three different growth stages(Phenological growth stages 12,14 and 16)in hydroponic culture.At the same time,the ^(15)N isotope tracer technique was applied to study the uptake and transport capacity of NO_(3)^(−)and NH_(4)^(+).Additionally,the expression level of genes(BnNPFs,BnNRT2s and BnAMTs)related to N uptake and transport in rapeseed germplasms with contrasting N efficiency were further analyzed by real-time quantitative PCR(RT-qPCR).【Result】Rapeseed germplasm‘498’showed superior advantages in plant growth and root development under different N concentrations,and the root morphological indexes(main root length,total root length,root surface area,root volume and lateral root number),biomass,N accumulation and N uptake efficiency were all significantly greater than those of germplasm‘428’.^(15)N isotope tracer test also showed that‘498’showed greater advantage in the uptake and accumulation of NO_(3)^(-)and NH_(4)^(+),especially for NH_(4)^(+),as indicated by the significant differences in the accumulation of ^(15)NH_(4)^(+)between two germplasms.The RT-qPCR analysis further found that under normal N conditions,the relative expressions of BnNPF6.3a,BnNRT2.1e,BnNPF7.2a,BnNPF7.2c,BnNPF6.2c,BnAMT1;2a,BnAMT1;3c,BnAMT1;4a,BnAMT2;1a and BnAMT2;1b(involved in the uptake and transport of NO_(3)^(-) and NH_(4)^(+))was significantly higher in‘498’than that in‘428’.While under low N stress,the relati

关 键 词：甘蓝型油菜 氮高效 根系形态 吸收转运 氮转运蛋白基因 

分 类 号：S565.4[农业科学—作物学]