Hypoxia and bicarbonate could limit the expression of iron acquisition genes in Strategy I plants by affecting ethylene synthesis and signaling in different ways

2013 ◽  
Vol 150 (1) ◽  
pp. 95-106 ◽  
Author(s):  
María J. García ◽  
María J. García-Mateo ◽  
Carlos Lucena ◽  
Francisco J. Romera ◽  
Carmen L. Rojas ◽  
...  
Keyword(s):  
Iron Acquisition ◽  
Ethylene Synthesis ◽  
Strategy I

Natural variation for Fe-efficiency is associated with upregulation of Strategy I mechanisms and enhanced citrate and ethylene synthesis in Pisum sativum L.

Planta ◽  
2012 ◽  
Vol 235 (6) ◽  
pp. 1409-1419 ◽  
Author(s):  
Ahmad H. Kabir ◽  
Nicholas G. Paltridge ◽  
Amanda J. Able ◽  
Jeffrey G. Paull ◽  
James C. R. Stangoulis
Keyword(s):  
Pisum Sativum ◽  
Natural Variation ◽  
Ethylene Synthesis ◽  
Pisum Sativum L ◽  
Strategy I

Comparison of iron acquisition from Fe–pyoverdine by strategy I and strategy II plants

Botany ◽  
2011 ◽  
Vol 89 (10) ◽  
pp. 731-735 ◽  
Author(s):  
Matt Shirley ◽  
Laure Avoscan ◽  
Eric Bernaud ◽  
Gérard Vansuyt ◽  
Philippe Lemanceau
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Species ◽  
Iron Uptake ◽  
Iron Acquisition ◽  
Iron Status ◽  
Iron Nutrition ◽  
Perennial Species ◽  
Major Class ◽  
Graminaceous Plants ◽  
Strategy I

Iron is an essential micronutrient for plants and associated microorganisms. However, the bioavailability of iron in cultivated soils is low. Plants and microorganisms have thus evolved active strategies of iron uptake. Two different iron uptake strategies have been described in dicotyledonous and monocotyledonous graminaceous species. In bacteria, this strategy relies on the synthesis of siderophores. Pyoverdines, a major class of siderophores produced by fluorescent pseudomonads, were previously shown to promote iron nutrition of the dicotyledonous species Arabidopsis thaliana L. (Heynh.), whereas contradictory reports were made on the contribution of those siderophores to the nutrition of graminaceous annuals. Furthermore, no information has so far been available on graminaceous perennials. Here, the contribution of purified pyoverdine of Pseudomonas fluorescens C7R12 to the iron nutrition of two annual and perennial graminaceous plants was assessed and compared with that of two dicotyledonous plant species. Fe–Pyoverdine promoted the iron status of all plant species tested. With the exception of wheat, this promotion was more dramatic in graminaceous species than in dicotyledonous species and was the highest in fescue, a perennial species. The incorporation of 15N-labeled pyoverdine was consistent with the effect on the iron status of the plants tested.

scholarly journals AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants

Cell Research ◽  
2005 ◽  
Vol 15 (8) ◽  
pp. 613-621 ◽  
Author(s):  
You Xi YUAN ◽  
Juan ZHANG ◽  
Dao Wen WANG ◽  
Hong Qing LING
Keyword(s):  
Arabidopsis Thaliana ◽  
Iron Acquisition ◽  
Strategy I

Shoot to root communication is necessary to control the expression of iron-acquisition genes in Strategy I plants

Planta ◽  
2012 ◽  
Vol 237 (1) ◽  
pp. 65-75 ◽  
Author(s):  
María J. García ◽  
Francisco J. Romera ◽  
Minviluz G. Stacey ◽  
Gary Stacey ◽  
Eduardo Villar ◽  
...  
Keyword(s):  
Iron Acquisition ◽  
Strategy I

Arthrobacter agilis UMCV2 induces iron acquisition in Medicago truncatula (strategy I plant) in vitro via dimethylhexadecylamine emission

2012 ◽  
Vol 362 (1-2) ◽  
pp. 51-66 ◽  
Author(s):  
Ma del Carmen Orozco-Mosqueda ◽  
Crisanto Velázquez-Becerra ◽  
Lourdes I. Macías-Rodríguez ◽  
Gustavo Santoyo ◽  
Idolina Flores-Cortez ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Iron Acquisition ◽  
Arthrobacter Agilis ◽  
Strategy I

Differences between two green algae in biological availability of iron bound to strong chelators

2006 ◽  
Vol 84 (3) ◽  
pp. 400-411 ◽  
Author(s):  
Harold G. Weger ◽  
Carlyn J. Matz ◽  
Rachel S. Magnus ◽  
Crystal N. Walker ◽  
Michael B. Fink ◽  
...  
Keyword(s):  
Green Algae ◽  
Green Alga ◽  
Vascular Plants ◽  
Iron Acquisition ◽  
Algal Species ◽  
Desferrioxamine B ◽  
Green Algal ◽  
Uptake Rates ◽  
Green Alga Chlorella ◽  
Strategy I

N,N′-di(2-hydroxybenzoyl)-ethylenediamine-N,N′-diacetic acid (HBED) is a very strong Fe3+ chelator. Strategy I vascular plants, which use a reductive system for iron acquisition, similar to many green algae, are able to access iron from HBED (R.L. Chaney. 1988. J. Plant Nutr. 11: 1033–1050). However, iron-limited cells of the Strategy I green alga Chlamydomonas reinhardtii Dangeard were unable to access iron present as Fe3+–HBED. In contrast, Fe3+ chelated with hydroxyethylethylenediaminetriacetic acid (HEDTA; a weaker chelator) was rapidly taken up by iron-limited Chlamydomonas cells. Chlamydomonas ferric reduction rates with Fe3+–HBED were approximately 15% of the rate observed with Fe3+–HEDTA, suggesting that low reduction rates with Fe3+–HBED might be one factor in the low rate of iron acquisition. By contrast, iron-limited cells of the Strategy I green alga Chlorella kessleri Fott et Nováková were able to rapidly assimilate Fe3+ chelated by HBED, although ferric reduction rates with Fe3+–HBED were approximately 38% the rate of activity with Fe3+–HEDTA. Similar differential iron uptake rates for the two algal species were obtained using the strong Fe3+ chelator (and siderophore analogue) desferrioxamine B mesylate and the cyanobacterial siderophore schizokinen. These results suggest that there are differences among Strategy I green algae in their abilities to acquire Fe3+ from various ferric chelates: not all Strategy I algae can equally access tightly complexed Fe3+. Chlamydomonas appears to be the first documented Strategy I organism that is unable to acquire iron from Fe3+–HBED. These results also suggest that green algal iron acquisition from siderophores is species dependent. Finally, we suggest that iron acquisition from Fe3+–HBED might serve as an assay for an organisms’ ability to access tightly complexed iron.

Risk, Desire and Adaptation: The Paradox of Queer Solidarity and the Political Possibility of Death Under Neoliberalism and Homonationalism

Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 185-200
Author(s):  
Natalie Kouri-Towe
Keyword(s):  
Human Rights ◽  
Social Movement ◽  
Political Activism ◽  
State Violence ◽  
The Political ◽  
Sexual Rights ◽  
Political Strategy ◽  
Rights Discourse ◽  
The Relationship ◽  
Strategy I

In 2015, Queers Against Israeli Apartheid Toronto (QuAIA Toronto) announced that it was retiring. This article examines the challenges of queer solidarity through a reflection on the dynamics between desire, attachment and adaptation in political activism. Tracing the origins and sites of contestation over QuAIA Toronto's participation in the Toronto Pride parade, I ask: what does it mean for a group to fashion its own end? Throughout, I interrogate how gestures of solidarity risk reinforcing the very systems that activists desire to resist. I begin by situating contemporary queer activism in the ideological and temporal frameworks of neoliberalism and homonationalism. Next, I turn to the attempts to ban QuAIA Toronto and the term ‘Israeli apartheid’ from the Pride parade to examine the relationship between nationalism and sexual citizenship. Lastly, I examine how the terms of sexual rights discourse require visible sexual subjects to make individual rights claims, and weighing this risk against political strategy, I highlight how queer solidarities are caught in a paradox symptomatic of our times: neoliberalism has commodified human rights discourses and instrumentalised sexualities to serve the interests of hegemonic power and obfuscate state violence. Thinking through the strategies that worked and failed in QuAIA Toronto's seven years of organising, I frame the paper though a proposal to consider political death as a productive possibility for social movement survival in the 21stcentury.

scholarly journals The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Danelle R. Weakland ◽  
Sara N. Smith ◽  
Bailey Bell ◽  
Ashootosh Tripathi ◽  
Harry L. T. Mobley
Keyword(s):  
Serratia Marcescens ◽  
Bloodstream Infection ◽  
Iron Acquisition ◽  
Gene Clusters ◽  
Clinical Isolates ◽  
Wild Type ◽  
Serratia Plymuthica ◽  
Content Type ◽  
Cas Assay ◽  
Essential Nutrient

ABSTRACT Serratia marcescens is a bacterium frequently found in the environment, but over the last several decades it has evolved into a concerning clinical pathogen, causing fatal bacteremia. To establish such infections, pathogens require specific nutrients; one very limited but essential nutrient is iron. We sought to characterize the iron acquisition systems in S. marcescens isolate UMH9, which was recovered from a clinical bloodstream infection. Using RNA sequencing (RNA-seq), we identified two predicted siderophore gene clusters (cbs and sch) that were regulated by iron. Mutants were constructed to delete each iron acquisition locus individually and in conjunction, generating both single and double mutants for the putative siderophore systems. Mutants lacking the sch gene cluster lost their iron-chelating ability as quantified by the chrome azurol S (CAS) assay, whereas the cbs mutant retained wild-type activity. Mass spectrometry-based analysis identified the chelating siderophore to be serratiochelin, a siderophore previously identified in Serratia plymuthica. Serratiochelin-producing mutants also displayed a decreased growth rate under iron-limited conditions created by dipyridyl added to LB medium. Additionally, mutants lacking serratiochelin were significantly outcompeted during cochallenge with wild-type UMH9 in the kidneys and spleen after inoculation via the tail vein in a bacteremia mouse model. This result was further confirmed by an independent challenge, suggesting that serratiochelin is required for full S. marcescens pathogenesis in the bloodstream. Nine other clinical isolates have at least 90% protein identity to the UMH9 serratiochelin system; therefore, our results are broadly applicable to emerging clinical isolates of S. marcescens causing bacteremia.

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