ACC对不同氮效率油菜生长后期硝态氮再利用的调控机理  

Regulation mechanisms of NO_3~– re-utilization by ACC at later growth stages of Brassica napus

作　　者：余音[1] 卢胜 宋海星[1] 官春云[2] 陈柯豪 张振华[1] 

机构地区：[1]湖南农业大学资源环境学院/南方粮油作物协同创新中心/土壤肥料资源高效利用国家工程实验室/农田污染控制与农业资源利用湖南省重点实验室/植物营养湖南省普通高等学校重点实验室,湖南长沙410128 [2]国家油料改良中心湖南分中心,湖南长沙410128

出　　处：《植物营养与肥料学报》2017年第5期1378-1386,共9页Journal of Plant Nutrition and Fertilizers

基　　金：湖南省自然科学基金青年基金(2016JJ3069);南方粮油作物协同创新中心;国家自然科学基金项目(31101596);湖南省百人计划项目;湖南农大1515人才项目资助

摘　　要：【目的】研究了进一步解析乙烯对油菜生长后期硝态氮(NO_3~–)再利用的影响,揭示植株生长后期氮素再利用的生理机制。【方法】以氮高效油菜品种湘油15(27号)与氮低效油菜品种814(6号)为试验材料,在15mmol/L氮水平下,每7天浇灌一次50 m L 100μmol/L 1-氨基环丙烷-1-羧酸(1-am-inocyclopropane-1-carboxylic acid,简称ACC),研究ACC对植物生长后期(花期、收获期)氮素再利用的影响及其与氮素利用效率(NUE)的关系。并用拟南芥野生型(col.0)和突变体(nrt1.5)材料作为验证,分别于玻璃顶网室和22℃恒温培养室进行砂培试验。【结果】ACC处理显著抑制了油菜Bn NRT1.5的表达,且植株的衰老可以显著诱导Bn NRT1.5的表达。相对于对照处理,ACC处理植株韧皮部汁液NO_3~–的再转运能力显著降低,导致下部叶NO_3~–含量显著升高,中部叶NO_3~–含量显著下降,上部叶NO_3~–含量无显著变化,进而导致植株含氮量和籽粒含氮量显著提高,以及以生物量和籽粒产量为基础的氮素利用效率(NUE)显著降低。由此推测,油菜生长后期氮素的再利用能力受到NRT1.5基因的显著调控。拟南芥野生型和突变体材料的验证结果表明,相对于拟南芥野生型(col.0)材料,拟南芥nrt1.5植株生长后期相对于col.0有更多的NO_3~–累积在植株衰老叶片中,更少的NO_3~–通过韧皮部转运到生长旺盛的新叶,植物生长后期氮素从老叶向新叶转运的再利用能力显著降低。【结论】油菜生长后期氮素的再利用能力受到ACC的显著调控,油菜和拟南芥NRT1.5基因表达量分别受到抑制或者发生基因突变时,会导致植株韧皮部汁液NO_3~–再转运量减少,更多NO_3~–累积在衰老叶片中而不能得以高效的再利用。因此,调控油菜生长后期NRT1.5的表达,提高油菜生长后期氮素的再转运和利用可以作为提高氮素利用效率的有效手段。[ Objectives ] The research will elucidate the regulation mechanisms of NO3^– re-utilization by 1-aminocyclopropane- 1-carboxylic acid （ACC） and reveal the physiological mechanisms of nitrogen （N） redistribution at later growth stage ofBrassica napus. [ Methods ] High N efficient variety Xiangyoul5 （No.27） and low N efficient variety 814 （No.6） were cultured in sand under 15 μmol/L nitrogen condition. ACC （50 mL 100 μmol/L） was irrigated every 7 days and the corresponding Arabidopsis thaliana wild type （col. 0） and mutant plants （nrtl.5） under greenhouse and environmental chamber respectively, to investigate the regulation mechanisms of NO3^– reutilization and its relationship with nitrogen use efficiency （NUE） during the later growth stages. [ Result ] The relative expression of BnNRT1.5 was significantly inhibited by ACC and senescence. Compared with the control treatment, NO3^– distribution ability in phloem sap was decreased significantly, resulted in NO3^– content of the lower leaves was increased significantly, NO3^– content of middle leaves was decreased significantly, but there was no significant changes of NO3^– content in upper leaves under ACC treatment, thus lead to the N content of plant tissues and seeds were increased significantly, and NUE based on biomass and seeds yield were decreased significantly. It was suggested that the N re-utilization capability is significant regulated by NRT1.5 gene. Using Arabidopsis thaliana wild type （col.0） and mutant （nrtl.5） plants to further elucidate the above results, compared with the wild type （col. 0）, higher proportion of NO3^– accumulated in the older leaves, lower proportion of NOr redistributed from older leaves to new leaves through phloem sap in mutant nrtl. 5 plants during the later growth stage, redistribution ability of NO3^– from older leaves to new leaves during senescence decreased significantly. [ Coneluslons ] N reutilization efficiency was regulated by ACC significantly at the lat

关 键 词：油菜 NRT1.5 ACC 氮素再利用 氮素利用效率 

分 类 号：S565.4[农业科学—作物学]