PubMed · 13789331
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
W H JAMES. 1960. Nitrogen balance.. https://pubmed.ncbi.nlm.nih.gov/13789331/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Nitrogen (N) is not only an essential macronutrient for plant growth and development but also functions as a pivotal signaling molecule that orchestrates adaptive responses to various abiotic stresses, including acidic stress, aluminum toxicity, salinity, drought, and extreme temperatures. This review synthesizes recent advances in our understanding of the molecular mechanisms by which N signaling, mediated by different N forms (e.g., NH4+ and NO3-), integrates with core stress-response pathways. We specifically discuss the genetic crosstalk between N sensing and key signaling cascades, including abscisic acid (ABA) signaling, the salt overly sensitive (SOS) pathway, and reactive oxygen species (ROS) homeostasis. The review details how this integration modulates physiological and transcriptional reprogramming through central regulators such as NIN-like proteins (NLPs), calcineurin B-like protein (CBL)-interacting protein kinase (CIPK), and the target of rapamycin (TOR) kinase, ultimately optimizing the trade-off between growth and tolerance. By establishing a unified genetic and molecular framework, this review aims to provide a theoretical basis for developing novel strategies in precision N management and molecular breeding to synergistically enhance N use efficiency (NUE) and abiotic stress tolerance in crops.
Leaf nitrogen allocation and photosynthetic proteins response can affect net photosynthetic rate (Pn), ultimately influencing crop yield under diverse environmental stresses. However, the internal relationship between Pn with leaf nitrogen allocation and photosynthetic proteins response under nitrogen or water scarcity in peanut (Arachis hypogaea L.) remains elusive. Here, comprehensive physiological property and proteomic analyses of peanut were conducted, revealing that both nitrogen and water scarcity remarkably impeded leaf growth and reduced Pn. Nitrogen deficiency significantly reduced the total nitrogen content per unit leaf area (Narea), chlorophyll content, and Pn, whereas drought stress caused a greater decline in photosynthetic nitrogen use efficiency (PNUE). The allocation of leaf nitrogen to photosynthetic components, including the carboxylation system and electron transport system in leaves, was significantly reduced when subjected to individual or combined deficiency. Proteomic analyses exhibited that several key photosynthetic proteins underwent a decrease under both single and combined water and nitrogen deficiency conditions. Thereby, Pn may decline due to the disruption of nitrogen allocation and down-regulated expression of photosynthetic proteins under these stress conditions. Our findings establish a benchmark for future research exploring the roles of leaf nitrogen allocation and photosynthetic proteins in the plant's response to nitrogen or water deficiency.
Plants possess regulatory mechanisms that enhance nitrogen (N) uptake under conditions of spatial and temporal variation in N availability. Study of regulatory mechanisms has focused almost exclusively on the uptake of inorganic N sources (i.e., ammonium (NH4+), nitrate (NO3-). Several lines of evidence, however, suggest that amino acids may constitute a potential source of N for a number of plant species, including conifers. In the present study, we investigated the uptake of amino acids and inorganic N in Scots pine (Pinus sylvestris L.) seedlings grown at different N concentrations. We compared the uptake rate of the individual N sources using U-[13C2], [15N]-glycine, U-[13C6], [15N4]-arginine, 15NH4, or 15NO3, and tested the short-term effect of N supply on the uptake rate of glycine, arginine and in field-grown Scots pine seedlings. Our data indicate that Scots pine seedlings can absorb substantial amounts of N in the form of intact arginine and glycine molecules. The data also suggest that Scots pine seedlings down-regulate their uptake of NH4+-N and arginine-N, but not of glycine-N in response to increased endogenous N concentrations.