Evidence for a Role of Calcium in Nitrate Assimilation in Wheat Seedlings

ABSTRACT The regulation of nitrate assimilation seems to follow the same pattern in all ascomycetes where this process has been studied. We show here by in vitro binding studies and a number of protection and interference techniques that the transcription factor mediating nitrate induction in Aspergillus nidulans, a protein containing a binuclear zinc cluster DNA binding domain, recognizes an asymmetrical sequence of the form CTCCGHGG. We further show that the protein binds to its consensus site as a dimer. We establish the role of the putative dimerization element by its ability to replace the analogous element of the cI protein of phage λ. Mutagenesis of crucial leucines of the dimerization element affect both the binding ability of the dimer and the conformation of the resulting protein-DNA complex. This is the first case to be described where a dimer recognizes such an asymmetrical nonrepeated sequence, presumably by each monomeric subunit making different contacts with different DNA half-sites.

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Comparative analysis of the effect of epibrassinolide and 6-benzylaminopurine on the key components of the glutathione complex in the roots of wheat seedling under salinity.

Biomics ◽

10.31301/2221-6197.bmcs.2021-3 ◽

2021 ◽

Vol 13 (1) ◽

pp. 20-26

Author(s):

D.R. Maslennikova ◽

F.M. Shakirova

Keyword(s):

Comparative Analysis ◽

Wheat Seedling ◽

Glutathione System ◽

Glutathione S Transferase ◽

Wheat Seedlings ◽

Comparable Level ◽

Endogenous Cytokinins ◽

Main Components ◽

First Time

The study carried out a comparative analysis of the effect of 24 epibrassinolide (EB) and 6-benzylaminopurine (BAP) on the growth and state of the main components of the glutathione system in the roots of wheat seedlings under the action of 2% NaCl, which for the first time revealed the ability of these phytohormones to similarly stabilize stress-induced decrease GSH / GSSG ratio, positively regulate the activity of glutathione reductase and glutathione-S-transferase. A comparable level of protective effect of BAP and EB on root length was revealed. The data obtained indicate that endogenous cytokinins may play the role of hormonal intermediates in the implementation of the protective.

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Exogenous Polyamines Only Indirectly Induce Stress Tolerance in Wheat Growing in Hydroponic Culture under Polyethylene Glycol-Induced Osmotic Stress

Life ◽

10.3390/life10080151 ◽

2020 ◽

Vol 10 (8) ◽

pp. 151 ◽

Cited By ~ 1

Author(s):

Izabela Marcińska ◽

Kinga Dziurka ◽

Piotr Waligórski ◽

Franciszek Janowiak ◽

Edyta Skrzypek ◽

...

Keyword(s):

Polyethylene Glycol ◽

Osmotic Stress ◽

Stress Tolerance ◽

Hydroponic Culture ◽

Low Molecular Weight ◽

Induce Stress ◽

Protective Mechanisms ◽

Wheat Seedlings ◽

Response To Stress

The aim of the present study was to evaluate the effect of osmotic stress caused by polyethylene glycol (PEG) 6000 in hydroponic culture on wheat seedlings of drought-resistant Chinese Spring (CS) and drought-susceptible SQ1 cultivar, and to examine the alleviative role of exogenous polyamines (PAs) applied to the medium. The assessment was based on physiological (chlorophyll a fluorescence kinetics, chlorophyll and water content) as well as biochemical (content of carbohydrates, phenols, proline, salicylic and abscisic acid, activity of low molecular weight antioxidants) parameters, measured after supplementation with PAs (putrescine, spermidine and spermine) on the 3rd, 5th and 7th day of the treatment. The results indicate that PAs ameliorate the effects of stress, indirectly and conditionally inducing stress tolerance of wheat seedlings. In contrast to the susceptible SQ1, the resistant CS cultivar activated its protective mechanisms, adjusting the degree of their activation to the level of the stress, depending on the genetic resources of the plant. Increased accumulation of antioxidants in the resistant CS in response to stress after the application of PAs confirms the hypothesis that PAs are involved in the signaling pathway determining the antioxidative response and the tolerance of wheat plants to drought stress.

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The role of activated carbon in protecting the roots of wheat seedlings under cadmium stress

Acta Ecologica Sinica ◽

10.5846/stxb201411132244 ◽

2016 ◽

Vol 36 (10) ◽

Author(s):

冯汉青 FENG Hanqing ◽

杜变变 DU Bianbian ◽

王庆文 WANG Qingwen ◽

王荣方 WANG Rongfang ◽

贾凌云 JIA Lingyun ◽

...

Keyword(s):

Activated Carbon ◽

Cadmium Stress ◽

Wheat Seedlings

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Salt-induced accumulation of glycine betaine is inhibited by high light in durum wheat

Functional Plant Biology ◽

10.1071/fp10177 ◽

2011 ◽

Vol 38 (2) ◽

pp. 139 ◽

Cited By ~ 34

Author(s):

Petronia Carillo ◽

Danila Parisi ◽

Pasqualina Woodrow ◽

Giovanni Pontecorvo ◽

Giuseppina Massaro ◽

...

Keyword(s):

Amino Acids ◽

Durum Wheat ◽

Glycine Betaine ◽

High Light ◽

Light Conditions ◽

Salt Treatment ◽

Wheat Seedlings ◽

Triticum Durum Desf ◽

Tyrosine Content

In this study, we determined the effects of both salinity and high light on the metabolism of durum wheat (Triticum durum Desf. cv. Ofanto) seedlings, with a special emphasis on the potential role of glycine betaine in their protection. Unexpectedly, it appears that high light treatment inhibits the synthesis of glycine betaine, even in the presence of salt stress. Additional solutes such as sugars and especially amino acids could partially compensate for the decrease in its synthesis upon exposure to high light levels. In particular, tyrosine content was strongly increased by high light, this effect being enhanced by salt treatment. Interestingly, a large range of well-known detoxifying molecules were also not induced by salt treatment in high light conditions. Taken together, our results question the role of glycine betaine in salinity tolerance under light conditions close to those encountered by durum wheat seedlings in their natural environment and suggest the importance of other mechanisms, such as the accumulation of minor amino acids.

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Bacterial nitrate assimilation: gene distribution and regulation

Biochemical Society Transactions ◽

10.1042/bst20110688 ◽

2011 ◽

Vol 39 (6) ◽

pp. 1838-1843 ◽

Cited By ~ 65

Author(s):

Víctor M. Luque-Almagro ◽

Andrew J. Gates ◽

Conrado Moreno-Vivián ◽

Stuart J. Ferguson ◽

David J. Richardson ◽

...

Keyword(s):

Rhodobacter Capsulatus ◽

Heterotrophic Bacteria ◽

Azotobacter Vinelandii ◽

Klebsiella Oxytoca ◽

Prokaryotic Genome ◽

Nitrate Assimilation ◽

Primary Role ◽

Bacterial Strains ◽

Global Nitrogen Cycle

In the context of the global nitrogen cycle, the importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognized. In contrast, the utilization of nitrate by heterotrophic bacteria has historically received less attention because the primary role of these organisms has classically been considered to be the decomposition and mineralization of dissolved and particulate organic nitrogen. In the pre-genome sequence era, it was known that some, but not all, heterotrophic bacteria were capable of growth on nitrate as a sole nitrogen source. However, examination of currently available prokaryotic genome sequences suggests that assimilatory nitrate reductase (Nas) systems are widespread phylogenetically in bacterial and archaeal heterotrophs. Until now, regulation of nitrate assimilation has been mainly studied in cyanobacteria. In contrast, in heterotrophic bacterial strains, the study of nitrate assimilation regulation has been limited to Rhodobacter capsulatus, Klebsiella oxytoca, Azotobacter vinelandii and Bacillus subtilis. In Gram-negative bacteria, the nas genes are subjected to dual control: ammonia repression by the general nitrogen regulatory (Ntr) system and specific nitrate or nitrite induction. The Ntr system is widely distributed in bacteria, whereas the nitrate/nitrite-specific control is variable depending on the organism.

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THE ROLE OF MOLYBDENUM IN NITRATE ASSIMILATION BY AGROBACTERIUM TUMEFACIENS

Biochemical Journal ◽

10.1042/bj0880239 ◽

1963 ◽

Vol 88 (2) ◽

pp. 239-242 ◽

Cited By ~ 4

Author(s):

CK RAMAKRISHNAKURUP ◽

CS VAIDYANATHAN

Keyword(s):

Agrobacterium Tumefaciens ◽

Nitrate Assimilation

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Reduced growth and yield of wheat with conservation cropping. II. Soil biological factors limit growth under direct drilling

Australian Journal of Agricultural Research ◽

10.1071/ar9950075 ◽

1995 ◽

Vol 46 (1) ◽

pp. 75 ◽

Cited By ~ 39

Author(s):

JA Kirkegaard ◽

R Munns ◽

RA James ◽

PA Gardner ◽

JF Angus

Keyword(s):

Shoot Growth ◽

Dominant Role ◽

Growth And Yield ◽

Cultivated Plants ◽

Biological Factors ◽

Wheat Seedlings ◽

Sowing Depth ◽

Cultivated Soil ◽

Controlled Environments

Wheat was grown in intact cores of soil removed from a field experiment in which seedlings had grown more slowly in direct-drilled soil than in cultivated soil. Experiments were conducted in controlled environments to resolve (1) whether shallower sowing of direct-drilled crops caused slower growth, (2) whether the soil factors causing the slower growth were physical or biological and (3) if biological, whether Rhizoctonia solani was the major pathogen. The conditions of the experiments removed possible constraints of water and nutrient supply but otherwise simulated the environment of wheat seedlings in southern Australia. Shallower sowing led to faster emergence and increased seedling growth, but irrespective of sowing depth, direct-drilled plants grew more slowly than plants in cultivated soil. Shoot growth of direct-drilled plants was 25-65% less than that of cultivated plants. These growth reductions were largely overcome by sterilizing the soil with y radiation or by fumigation with methyl bromide, indicating that biological factors were primarily responsible. Rhizoctonia was implicated as the cause of the reduced shoot growth when infection was severe (>3 on a 0-5 scale). There was no correlation between infection severity and shoot growth at moderate levels (<3) and significant reductions in shoot growth occurred in the absence of Rhizoctonia. These reductions were evident on the first leaf suggesting a direct influence on shoot growth rather than one mediated through inadequate uptake of water or nutrients. Infection of the germinating seed by Pythium spp. or the effects of phytohormones produced by inhibitory bacteria on the roots are possible causes of reduced shoot growth of direct-drilled seedlings. The dominant role of biological factors in determining plant response to soil management indicates the need for further studies to identify the organisms responsible, to determine the mechanism by which they influence shoot growth, and the effect of management on their populations and activity.

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