茶树氮素吸收利用机制研究进展

铵态氮(NH4~+)和硝态氮(NO_3~-)是茶树吸收利用的两种主要氮素形态,且茶树具有对NH4~+偏性利用的特点,其对NH4~+的吸收利用效率明显高于NO_3~-,造成这种差异的原因可能在于茶树对NH4~+、NO_3~-吸收、同化机制的差异。从代谢途径来看,茶树对NH4~+、NO_3~-的吸收利用均首先需要通过对氮素的转运,然后再参与谷氨酰胺合成酶/谷酰胺–α–酮戊二酸氨基转移酶(GS/GOGAT)同化过程。系统地综述了茶树氮素利用的营养特性及对参与氮素吸收、同化过程所涉及关键基因的研究现状;同时重点关注氮素同化中限速酶——谷氨酰胺合成酶(GS)编码基因家族成员的相关研究,为解析茶树氮素偏性利用机制提供新的研究点。

Research Progress of Nitrogen Utilization and Assimilation in Tea Plant

Tea plantCamellia sinensis (L.) O.Kuntze] is an ammonium preferring plant species,and the two main inorganic nitrogen sources ammonium (NH4+) and nitrate (NO3-) are absorbed with distinct absorption and assimilation rates.Previous studies showed that preference assimilation of ammonium in tea plant maybe due to the different mechanisms behind the processes of utilization and assimilation of these two nitrogen forms.Glutamine synthetase (GS) has been dissected to restrict nitrogen assimilation in plants.In this review,we sort out the research progress of pivotal role of genes involved in nitrogen absorption and assimilation in tea plant,specifically the GS1 family gene,which would help to clarify the whole process of nitrogen utilization and assimilation in tea plant.