Molecular identification and physiological functional analysis of NtNRT1.1B that mediated nitrate long-distance transport and improved plant growth when overexpressed in tobacco.

Although recent physiological studies demonstrate that flue-cured tobacco preferentially utilizes nitrate ( ) or ammonium nitrate (NHNO), and possesses both high- and low-affinity uptake systems for , little is known about the molecular component(s) responsible for acquisition and translocation in this crop. Here we provide experimental data showing that with a 1,785-bp coding sequence exhibited a function in mediating transport associated with tobacco growth on nutrition. Heterologous expression of in the uptake-defective yeast enabled a growth recovery of the mutant on 0.

Phenotypical evidence of effective amelioration of ammonium-inhibited plant (root) growth by exogenous low urea.

Ammonium and nitrate are major soil inorganic-nitrogen sources for plant growth, but many species cultivated with even low millimolar NH as a sole N form display a growth retardation. To date, critical biological components and applicable approaches involved in the effective enhancement of NH tolerance remain to be thoroughly explored. Here, we report phenotypical traits of urea-dependent improvement of NH-suppressed plant/root growth.

Evidence that exogenous urea acts as a potent cue to alleviate ammonium-inhibition of root system growth of cotton plant (Gossypium hirsutum).

Many plants grown with low-millimolar concentration of NH as a sole nitrogen source develop NH -toxicity symptoms. To date, crucial molecular identities and a practical approach involved in the improvement of plant NH -tolerance remain largely unknown. By phenotyping of upland cotton grown on varied nitrogen forms, we came across a phenomenon that caused sub-millimolar concentrations of urea (e.

Molecular identification of a root apical cell-specific and stress-responsive enhancer from an enhancer trap line.

Background: Plant root apex is the major part to direct the root growth and development by responding to various signals/cues from internal and soil environments. To study and understand root system biology particularly at a molecular and cellular level, an T-DNA insertional enhancer trap line J3411 expressing reporters (GFP) only in the root tip was adopted in this study to isolate a DNA fragment.

Results: Using nested PCR, DNA sequencing and sequence homology search, the T-DNA insertion site(s) and its flanking genes were characterised in J3411 line.

Molecular identification and functional characterization of GhAMT1.3 in ammonium transport with a high affinity from cotton (Gossypium hirsutum L.).

Ammonium (NH ) represents a primary nitrogen source for many plants, its effective transport into and between tissues and further assimilation in cells determine greatly plant nitrogen use efficiency. However, biological components involved in NH movement in woody plants are unclear. Here, we report kinetic evidence for cotton NH uptake and molecular identification of certain NH transporters (AMTs) from cotton (Gossypium hirustum).

Coding-Sequence Identification and Transcriptional Profiling of Nine and Four From Tobacco Revealed Their Differential Regulation by Developmental Stages, Nitrogen Nutrition, and Photoperiod.

Although many members encoding different ammonium- and nitrate-transporters (AMTs, NRTs) were identified and functionally characterized from several plant species, little is known about molecular components for [Formula: see text]- and [Formula: see text] acquisition/transport in tobacco, which is often used as a plant model for biological studies besides its agricultural and industrial interest. We reported here the first molecular identification in tobacco () of nine and four , which are respectively divided into four () and two () clusters and whose functionalities were preliminarily evidenced by heterologous functional-complementation in yeast or Arabidopsis. Tissue-specific transcriptional profiling by qPCR revealed that / mRNA occurred widely in leaves, flower organs and roots; only were strongly transcribed in the aged leaves, implying their dominant roles in N-remobilization from source/senescent tissues.

Molecular identification of tobacco NtAMT1.3 that mediated ammonium root-influx with high affinity and improved plant growth on ammonium when overexpressed in Arabidopsis and tobacco.

Although biological functions of ammonium (NH) transporters (AMTs) have been intensively studied in many plant species, little is known about molecular bases responsible for NH movement in tobacco. Here, we reported the identification and functional characterization of a putative NH transporter NtAMT1.3 from tobacco (Nicotiana tabacum).

Molecular identification and functional analysis of a maize (Zea mays) DUR3 homolog that transports urea with high affinity.

Successful molecular cloning and functional characterization of a high-affinity urea permease ZmDUR3 provide convincing evidence of ZmDUR3 roles in root urea acquisition and internal urea-N-remobilization of maize plants. Urea occurs ubiquitously in both soils and plants. Being a major form of nitrogen fertilizer, large applications of urea assist cereals in approaching their genetic yield potential, but due to the low nitrogen-use efficiency of crops, this practice poses a severe threat to the environment through their hypertrophication.

A plant homolog of animal glutamate receptors is an ion channel gated by multiple hydrophobic amino acids.

Ionotropic glutamate receptors (iGluRs) are ligand-gated cation channels that mediate neurotransmission in animal nervous systems. Homologous proteins in plants have been implicated in root development, ion transport, and several metabolic and signaling pathways. AtGLR3.

Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis.

• Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis. • We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (K(m) of 7.55 μM) transport system for urea-uptake by rice roots (Oryza sativa).

Glutamate receptor-like genes form Ca2+ channels in pollen tubes and are regulated by pistil D-serine.

Elevations in cytosolic free calcium concentration ([Ca(2+)](cyt)) constitute a fundamental signal transduction mechanism in eukaryotic cells, but the molecular identity of Ca(2+) channels initiating this signal in plants is still under debate. Here, we show by pharmacology and loss-of-function mutants that in tobacco and Arabidopsis, glutamate receptor-like channels (GLRs) facilitate Ca(2+) influx across the plasma membrane, modulate apical [Ca(2+)](cyt) gradient, and consequently affect pollen tube growth and morphogenesis. Additionally, wild-type pollen tubes grown in pistils of knock-out mutants for serine-racemase (SR1) displayed growth defects consistent with a decrease in GLR activity.

Identification and characterization of proteins involved in rice urea and arginine catabolism.

Rice (Oryza sativa) production relies strongly on nitrogen (N) fertilization with urea, but the proteins involved in rice urea metabolism have not yet been characterized. Coding sequences for rice arginase, urease, and the urease accessory proteins D (UreD), F (UreF), and G (UreG) involved in urease activation were identified and cloned. The functionality of urease and the urease accessory proteins was demonstrated by complementing corresponding Arabidopsis (Arabidopsis thaliana) mutants and by multiple transient coexpression of the rice proteins in Nicotiana benthamiana.

Evidence that L-glutamate can act as an exogenous signal to modulate root growth and branching in Arabidopsis thaliana.

The roots of many plant species are known to use inorganic nitrogen, in the form of , as a cue to initiate localized root proliferation within nutrient-rich patches of soil. We report here that, at micromolar concentrations and in a genotype-dependent manner, exogenous l-glutamate is also able to elicit complex changes in Arabidopsis root development. l-Glutamate is perceived specifically at the primary root tip and inhibits mitotic activity in the root apical meristem, but does not interfere with lateral root initiation or outgrowth.

Urea transport by nitrogen-regulated tonoplast intrinsic proteins in Arabidopsis.

Urea is the major nitrogen (N) form supplied as fertilizer in agricultural plant production and also an important N metabolite in plants. Because urea transport in plants is not well understood, the aim of the present study was to isolate urea transporter genes from the model plant Arabidopsis. Using heterologous complementation of a urea uptake-defective yeast (Saccharomyces cerevisiae) mutant allowed to isolate AtTIP1;1, AtTIP1;2, AtTIP2;1, and AtTIP4;1 from a cDNA library of Arabidopsis.

AtDUR3 encodes a new type of high-affinity urea/H+ symporter in Arabidopsis.

Urea is the major nitrogen form supplied as fertilizer in agricultural plant production but also an important nitrogen metabolite in plants. We report the cloning and functional characterization of AtDUR3, a high-affinity urea transporter in plants. AtDUR3 contains 14 putative transmembrane-spanning domains and represents an individual member in Arabidopsis that belongs to a superfamily of sodium-solute symporters.