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土壤中的氮素因土壤类型和季节变化产生异质性。在长期的进化过程中,植物适应各自的氮营养生境,形成了对NO3-/NH4+吸收的分子机制。饱和高亲和传输系统(HATS)中,植物在不同的转录基因控制下吸收NO3-/NH4+,表现出对两种氮源的偏选性。这种偏选性主要取决于植物种的特性,但是NO3-/NH4+的吸收受光照、介质N强度、pH值、外源氨基酸和温度等生境因子的影响,同时植物的营养生境也因NO3-/NH4+的吸收被深刻改造。硝酸还原酶(NR)在氮同化过程中作用于NO3-还原阶段,其活性受各种生境因子的制约,影响植物对NO3-吸收利用。
Nitrogen in soil is heterogeneous due to soil type and seasonal variation. In the long-term evolution, plants adapt to their respective nitrogen nutrition habitat, forming a molecular mechanism for NO3- / NH4 + uptake. In saturated high affinity delivery system (HATS), plants absorb NO3- / NH4 + under the control of different transcriptional genes, exhibiting a preference for both nitrogen sources. However, the absorption of NO3- / NH4 + is influenced by the habitats such as light, medium N, pH, exogenous amino acids and temperature, and the vegetative habitats of plants are also affected by NO3- / NH4 + absorption has been profoundly modified. Nitrate reductase (NR) plays a role in the process of nitrogen assimilation in the NO3-reduction stage, and its activity is restricted by various habitat factors and affects plant NO3-uptake and utilization.