Nitric oxide (NO) serves as a signal in plants. An Arabidopsis mutant ( Atnos1 ) was identified that had impaired NO production, organ growth, and abscisic acid–induced stomatal movements. Expression of AtNOS1 with viral promoter plants resulted overproduction NO. Purified protein used the substrates arginine nicotinamide adenine dinucleotide phosphate activated by Ca 2+ calmodulin-like mammalian endothelial nitric synthase neuronal synthase, yet it is distinct enzyme no sequence...

Abstract The genomic response to low levels of nitrate was studied in Arabidopsis using the Affymetrix ATH1 chip containing more than 22,500 probe sets. plants were grown hydroponically sterile liquid culture on ammonium as sole source nitrogen for 10 d, then treated with 250 μm 20 min. much stronger roots (1,176 genes showing increased or decreased mRNA levels) shoots (183 responding genes). In addition known nitrate-responsive (e.g. those encoding transporters, reductase, nitrite...

Using a new Arabidopsis (Arabidopsis thaliana) mutant (Atnrt2.1-nrt2.2) we confirm that concomitant disruption of NRT2.1 and NRT2.2 reduces inducible high-affinity transport system (IHATS) by up to 80%, whereas the constitutive (CHATS) was reduced 30%. Nitrate influx via low-affinity (LATS) unaffected. Shoot-to-root ratios were significantly compared wild-type plants, major effect being upon shoot growth. In another uniquely disrupted in (Atnrt2.1), IHATS 72%, neither CHATS nor LATS fluxes...

The non-protein amino acid γ-aminobutyric (GABA) has been proposed to be an ancient messenger for cellular communication conserved across biological kingdoms. GABA well-defined signalling roles in animals; however, whilst accumulates plants under stress it not determined if, how, where and when acts as endogenous plant molecule. Here, we establish a bona fide signal, acting via mechanism found animals. Using Arabidopsis thaliana, show guard cell production is necessary sufficient reduce...

Four low-affinity (NRT1), and seven high-affinity (NRT2) nitrate transporter gene homologues have been identified in Arabidopsis thaliana. We investigated the transcript abundances of all eleven genes shoot root tissues response to provision 1 mM NO3–, using relative quantitative RT-PCR. Based upon this criterion, were classified as nitrate-inducible, nitrate-repressible, or nitrate-constitutive. AtNRT1.1, 2.1, 2.2 strongly induced by peaking at 3–12 h subsequently declining. By contrast...

Summary Putative high‐affinity nitrate (NO 3 – ) transporter genes, designated Nrt2;1At and Nrt2;2At , were isolated from Arabidopsis thaliana by RT–PCR using degenerate primers. The genes shared 86% 89% identity at the amino acid nucleotide levels, respectively, while their proteins 30–73% identities with other eukaryotic highaffinity NO transporters. Both induced but gene expression was not apparent in 2‐ 5‐day‐old plants. By 10 days, thereafter, roots substantially higher than for gene....

The NAR2 protein of Chlamydomonas reinhardtii has no known transport activity yet it is required for high-affinity nitrate uptake. Arabidopsis (Arabidopsis thaliana) possesses two genes, AtNRT3.1 and AtNRT3.2, that are similar to the C. gene. accounts greater than 99% NRT3 mRNA induced 6-fold by nitrate. AtNRT3.2 was expressed constitutively at a very low level did not compensate loss in Atnrt3.1 mutants. Nitrate uptake roots induction gene expression were analyzed T-DNA mutants, Atnrt3.1-1...

Plant aluminum-activated malate transporters (ALMTs) are currently classified as anion channels; they also known to be regulated by diverse signals, leading a range of physiological responses. Gamma-aminobutyric acid (GABA) regulation flux through ALMT proteins requires specific amino motif in ALMTs that shares similarity with GABA binding site mammalian GABAA receptors. Here, we explore why TaALMT1 activation leads negative correlation between efflux and endogenous concentrations ([GABA]i)...

Summary Despite the great agricultural and ecological importance of efficient use urea‐containing nitrogen fertilizers by crops, molecular physiological identities urea transport in higher plants have been investigated only Arabidopsis . We performed short‐time urea‐influx assays which identified a low‐affinity high‐affinity ( K m 7.55 μM) system for urea‐uptake rice roots Oryza sativa ). A transporter OsDUR3 from was functionally characterized here first time among crops. encodes an...

Significance The legume/rhizobia symbiosis involves a root-based exchange of bacterial fixed nitrogen for plant-derived photosynthetic carbon. takes place within the legume root nodule, which is specialized tissue that develops in response to plant and signal exchange. bacteria reside cells inside nodule. In this study, we explore activity membrane-bound soybean transcription factor, Glycine max basic–helix-loop–helix membrane 1, important nodule growth linked unique class ammonium channels...

The spike of a cereal plant is the grain-bearing organ whose physical characteristics are proxy measures grain yield. ability to detect and characterise spikes from 2D images plants, such as wheat, therefore provides vital information on tiller number yield potential. We have developed novel detection method for wheat plants involving, firstly, an improved colour index segmentation and, secondly, neural network-based using Laws texture energy detection. step was further by removing noise...

Over 100 million tonnes of nitrogen (N) fertiliser are applied globally each year to maintain high yields in agricultural crops. The rising price N fertilisers has made them a major cost for farmers. Inefficient use leads substantial environmental problems through contamination air and water resources can be significant economic cost. Consequently, there is considerable need improve the way used farming systems. efficiency with which crops – nitrogen-use (NUE) currently quite low cereals....

Nitrogen is an essential nutrient for plants, but crop plants are inefficient in the acquisition and utilization of applied nitrogen. This often results producers over applying nitrogen fertilizers, which can negatively impact environment. The development with more efficient usage is, therefore, important research goal achieving greater agricultural sustainability. We utilized genetically modified rice lines over-expressing a barley alanine aminotransferase ( HvAlaAT ) to help characterize...

ABSTRACT In order to investigate the molecular basis of high‐affinity ammonium absorption by roots rice plants ( Oryza sativa subspecies indica ) expression patterns three members AMT1 family genes in seedling response altered nitrogen provision and diurnal changes irradiance were examined. The 13 NH 4 + influx transcript levels OsAMT1.1 decreased several fold within 48 h when acclimated 10 µ m external for 3 weeks transferred . Likewise , there was an equally rapid up‐regulation roots....

Degradation of nitrogen-rich purines is tightly and oppositely regulated under drought low nitrogen supply in bread wheat. Allantoin a key target metabolite for improving homeostasis stress. The allantoin an intermediate the catabolism (components nucleotides) known its housekeeping role (N) recycling also function N transport storage nodulated legumes. was shown to differentially accumulate upon abiotic stress range plant species but little about cereals. To address this, purine catabolic...

The key aim was to assess the genetic variation for nitrogen (N) response and stability in spring wheat germplasm determine scope improvement of use efficiency (NUE) under water-limited, low yielding conditions. A further evaluate NUE NUE-protein yield (PY) as suitable NUE-related traits selection. measured included grain (GY, kg ha−1) (kg GY kg−1 N) varying N applications at all sites, protein (NUE-PY), harvest index plant height some sites. In addition, two trials used seeding rates...

Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. fertilisers represent significant production cost, both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass after establishment showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation NUE has been shown previously. Here we describe the genetic characterisation identify loci underlying response...

There are many reports of an arginine‐dependent nitric oxide synthase activity in plants; however, the gene(s) or protein(s) responsible for this have yet to be convincingly identified. To measure activity, studies relied on a citrulline‐based assay that measures formation l ‐citrulline from ‐arginine using ion exchange chromatography. In article, we report when such assays used with protein extracts Arabidopsis , was observed, but it produced product other than citrulline. TLC analysis...

Leaf senescence, an indicator of plant age and ill health, is important phenotypic trait for the assessment a plant’s response to stress. Manual inspection however, time consuming, inaccurate subjective. In this paper we propose objective evaluation senescence by color image analysis use in high throughput phenotyping pipeline. As platforms are designed capture whole-of-plant features, camera lenses settings inappropriate fine detail. Specifically, colors images may not represent true...

Genetic variation has been observed in both protein concentration wheat grain and total content (protein yield). Here we describe the genetic analysis of for response to nitrogen (N) supply locate significant genomic regions controlling components a spring population. In total, six N use efficiency (NUE) field trials were carried out target traits sub-population doubled haploid lines derived from cross between two Australian varieties, RAC875 Kukri, Southern Western Australia 2011 2013....

1. Experiments were done in vitro and situ the caeca to measure ammonia production from uric acid its absorption. 2. When was introduced into a caecal sac containing mixed micro-organisms 0.77 disappeared 1 h, with concomitant appearance of ammonia. 3. Amounts produced added [15N] after 30 min medium 10 0.28 0.25 respectively 15N. 4. About 0.92 lumen fluid min. 5. It is concluded that by rapidly absorbed.