植物叶片氮磷养分重吸收规律及其调控机制研究进展

植物养分重吸收是植物组织或器官在衰老脱落前将部分养分(主要如氮、磷)转移到其他成活组织的过程,能延长养分在植物体内的存留时间,提高养分利用效率,减少植物对土壤养分的依赖,是植物适应环境的重要策略之一。本研究综述了土壤水分和肥力、光照、温度等环境因子和寿命、个体发育等遗传特性对植物叶片氮磷养分重吸收的影响。不同生活型或功能型的叶片养分重吸收不同;施肥会改变土壤速效养分的含量和比例,从而调控叶片养分重吸收;土壤水分通过调节土壤养分有效性而影响叶片养分重吸收;植物在生长过程中,不同时期对养分的需求有所差异,对养分的敏感程度和吸收能力也各不相同,从而表现出不同叶片养分重吸收特征;除了叶片之外,植物的其他组织器官(如,细茎、树木的芯材和能够储存养分的根)也可以进行养分重吸收。因此,植物叶片养分重吸收易受多种因素的影响,不同物种的重吸收能力存在差异,同一物种在不同时、空及相关因素变化下的重吸收特性也不同。深入研究植物养分重吸收规律和调控机制有助于进一步揭示植物的环境适应性,能为提高水肥管理水平,权衡生产力和适应性,实现系统生产和生态可持续发展提供理论依据。

Research progress in nitrogen and phosphorus resorption from senesced leaves and the influence of ontogenetic and environmental factors

Nutrient resorption of a plant is a fundamental process in which the nutrients,i.e.nitrogen and phosphorus,in older tissues or organs are partly retranslocated into other vital parts before the tissues or organs senesce and fall.This process can retain nutrients within the plant that would otherwise be lost and enhance the nutrient use,thus reducing the dependence of a plant on soil nutrient availability.Resorption is an important strategy for adaption to adverse environments and for promotion of competitive ability.This review summarizes findings on the effects of environmental factors (i.e.soil fertility and water) and ontogenetic influences (i.e.growth stage and leaf lifespan) on nitrogen (N) and phosphorus (P) resorption from senesced leaves.Nutrient resorption varies among plant life forms or functional groups (e.g.N2-fixing and non-N2-fixing).Fertilizer application and irrigation can change nutrient availability in soils,influencing nutrient resorption.Plants sense and absorb nutrients differently at different growth stages,leading to ontogenetic changes in patterns of nutrient resorption.Resorption is not confined to leaves and may occur in other plant organs.In summary,nutrient resorption is influenced by multiple factors including ontogenetic and environmental signals.Improved knowledge about nutrient resorption may help understanding of how plants adapt to adverse environments and provide theoretical knowledge to support the development of more sustainable agricultural production practices.