Nitrogen-assimilating enzymes in land plants and algae: phylogenic and physiological perspectives.

Physiol Plant

Department of Biomolecular Science, Faculty of Science, Toho University, Chiba 274-8510, Japan Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.

Published: September 2002

An important biochemical feature of autotrophs, land plants and algae, is their incorporation of inorganic nitrogen, nitrate and ammonium, into the carbon skeleton. Nitrate and ammonium are converted into glutamine and glutamate to produce organic nitrogen compounds, for example proteins and nucleic acids. Ammonium is not only a preferred nitrogen source but also a key metabolite, situated at the junction between carbon metabolism and nitrogen assimilation, because nitrogen compounds can choose an alternative pathway according to the stages of their growth and environmental conditions. The enzymes involved in the reactions are nitrate reductase (EC 1.6.6.1-2), nitrite reductase (EC 1.7.7.1), glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 1.4.1.13-14, 1.4.7.1), glutamate dehydrogenase (EC 1.4.1.2-4), aspartate aminotransferase (EC 2.6.1.1), asparagine synthase (EC 6.3.5.4), and phosphoenolpyruvate carboxylase (EC 4.1.1.31). Many of these enzymes exist in multiple forms in different subcellular compartments within different organs and tissues, and play sometimes overlapping and sometimes distinctive roles. Here, we summarize the biochemical characteristics and the physiological roles of these enzymes. We also analyse the molecular evolution of glutamine synthetase, glutamate synthase and glutamate dehydrogenase, and discuss the evolutionary relationships of these three enzymes.

Download full-text PDF

Source
http://dx.doi.org/10.1034/j.1399-3054.2002.1160101.xDOI Listing

Publication Analysis

Top Keywords

land plants
8
plants algae
8
nitrate ammonium
8
nitrogen compounds
8
glutamine synthetase
8
glutamate synthase
8
glutamate dehydrogenase
8
nitrogen
5
glutamate
5
nitrogen-assimilating enzymes
4

Similar Publications

Exploring the dual roles of sec-dependent effectors from Candidatus Liberibacter asiaticus in immunity of citrus plants.

Plant Cell Rep

January 2025

MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China.

The three SDEs of CLas were expressed in citrus leaves by AuNPs-PEI mediated transient expression system, and promoted the proliferation of CLas and inhibited citrus immunity. Huanglongbing (HLB) is the most severe bacterial disease of citrus caused by Candidatus Liberibacter asiaticus (CLas). CLas suppress host immune responses and promote infection by sec-dependent effectors (SDEs), thus insight into HLB pathogenesis is urgently needed to develop effective management strategies.

View Article and Find Full Text PDF

An involvement of a new zinc finger protein PbrZFP719 into pear self-incompatibility reaction.

Plant Cell Rep

January 2025

State Key Laboratory of Crop Genetics and Germplasm Enhancement, Saya Institute of Nanjing Agricultural University, Nanjing Agricultural University, Nanjing, 211800, China.

This study indicated that the CCHC-type zinc finger protein PbrZFP719 involves into self-incompatibility by affecting the levels of reactive oxygen species and cellulose content at the tips of pollen tubes. S-RNase-based self-incompatibility (SI) facilitates cross-pollination and prevents self-pollination, which in turn increases the costs associated with artificial pollination in fruit crops. Self S-RNase exerts its inhibitory effects on pollen tube growth by altering cell structures and components, including reactive oxygen species (ROS) level and cellulose content.

View Article and Find Full Text PDF

The homeotic transformation of stamens into pistil-like structures (pistillody) causes cytoplasmic male sterility (CMS). This phenomenon is widely present in plants, and might be induced by intracellular communication (mitochondrial retrograde signaling), but its systemic regulating mechanism is still unclear. In this study, morphological observation showed that the stamens transformed into pistil-like structures, leading to flat and dehiscent pistils, and fruit set decrease in sua-CMS (MS K326, somatic fusion between Nicotiana.

View Article and Find Full Text PDF

Background: Innovation in crop establishment is crucial for wheat productivity in drought-prone climates. Seedling establishment, the first stage of crop productivity, relies heavily on root and coleoptile system architecture for effective soil water and nutrient acquisition, particularly in regions practicing deep planting. Root phenotyping methods that quickly determine coleoptile lengths are vital for breeding studies.

View Article and Find Full Text PDF

This study investigated the effects of non-thermal atmospheric plasma (NTAP) treatment on the growth, chemical composition, and biological activity of geranium (Pelargonium graveolens L'Herit) leaves. NTAP was applied at a frequency of 13.56 MHz, exposure time of 15 s, discharge temperature of 25 °C, and power levels (T1 = 50, T2 = 80, and T3 = 120 W).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!