Alkaline stress and iron deficiency regulate iron uptake and riboflavin synthesis gene expression differently in root and leaf tissue: implications for iron deficiency chlorosis

Iron deficiency chlorosis (FeDC) can cause significant seed yield reduction in dry beans (Phaseolus vulgaris L.) grown on high-pH calcareous soils. To determine the effects of FeDC on seed yield, and the effect of Fe-spray as a correction factor for FeDC, 22 breeding lines/cultivars were planted on high-pH (8.0), calcareous (3.2–3.5 calcium carbonate equivalent), and low-Fe (1.8–4.2 ppm DTPA) sandy clay loam Tripp soils at Mitchell and Scottsbluff in western Nebraska. A split-plot design was used with Fe treatments as main plots and breeding lines/cultivars as subplots. Three foliar sprays of Fe-EDDHA (2.4 kg·ha–1) were applied at V4, R5, and R7 dry bean growth stages, during 1996 and 1997. Leaf chlorosis was measured simultaneously by using a Minolta Chroma-meter (CIE L* a* b* color space system), a Minolta Chlorophyll-meter (chlorophyll content index), and by visual ratings (1 = normal green to 5 = severe chlorosis). In 1996 no significant Fe-spray × line interaction (P = 0.776) and Fe-spray effect (P = 0.884) on seed yield was observed. Breeding lines showed significant differences in seed yield (P = 0.0001) with WM2-96-5 being the highest-yielding line (4047 kg·ha–1). In 1997 a significant Fe spray × line interaction (P = 0.029) was observed. The cultivar Chase without Fe spray (3375 kg·ha–1), and lines WM2-96-5 (3281 kg·ha–1), WM2-96-8 (3171 kg·ha–1) with Fe spray were the highest yielding entries under those treatments. Differences in visual ratings after the third Fe spray in 1997 were significant (P = 0.004) for Fe spray × line interaction. In 1996 visual ratings were different only for breeding lines. Chlorophyll content index showed a significant Fe spray × line interaction after the second Fe spray (P = 0.022) and after the third Fe spray (P = 0.0003) in 1997.

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Expression Patterns in Reductive Iron Assimilation and Functional Consequences during Phagocytosis of Lichtheimia corymbifera, an Emerging Cause of Mucormycosis

Journal of Fungi ◽

10.3390/jof7040272 ◽

2021 ◽

Vol 7 (4) ◽

pp. 272

Author(s):

Felicia Adelina Stanford ◽

Nina Matthias ◽

Zoltán Cseresnyés ◽

Marc Thilo Figge ◽

Mohamed I. Abdelwahab Hassan ◽

...

Keyword(s):

Gene Expression ◽

Iron Uptake ◽

Intracellular Transport ◽

Pathogenic Fungus ◽

Expression Patterns ◽

Iron Depletion ◽

Iron Assimilation ◽

Human Pathogenic Fungus ◽

Hyphal Formation ◽

Yeast Mutants

Iron is an essential micronutrient for most organisms and fungi are no exception. Iron uptake by fungi is facilitated by receptor-mediated internalization of siderophores, heme and reductive iron assimilation (RIA). The RIA employs three protein groups: (i) the ferric reductases (Fre5 proteins), (ii) the multicopper ferroxidases (Fet3) and (iii) the high-affinity iron permeases (Ftr1). Phenotyping under different iron concentrations revealed detrimental effects on spore swelling and hyphal formation under iron depletion, but yeast-like morphology under iron excess. Since access to iron is limited during pathogenesis, pathogens are placed under stress due to nutrient limitations. To combat this, gene duplication and differential gene expression of key iron uptake genes are utilized to acquire iron against the deleterious effects of iron depletion. In the genome of the human pathogenic fungus L. corymbifera, three, four and three copies were identified for FRE5, FTR1 and FET3 genes, respectively. As in other fungi, FET3 and FTR1 are syntenic and co-expressed in L. corymbifera. Expression of FRE5, FTR1 and FET3 genes is highly up-regulated during iron limitation (Fe-), but lower during iron excess (Fe+). Fe- dependent upregulation of gene expression takes place in LcFRE5 II and III, LcFTR1 I and II, as well as LcFET3 I and II suggesting a functional role in pathogenesis. The syntenic LcFTR1 I–LcFET3 I gene pair is co-expressed during germination, whereas LcFTR1 II- LcFET3 II is co-expressed during hyphal proliferation. LcFTR1 I, II and IV were overexpressed in Saccharomyces cerevisiae to represent high and moderate expression of intracellular transport of Fe3+, respectively. Challenge of macrophages with the yeast mutants revealed no obvious role for LcFTR1 I, but possible functions of LcFTR1 II and IVs in recognition by macrophages. RIA expression pattern was used for a new model of interaction between L. corymbifera and macrophages.

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“Limiting access to iron decreases infection of Atlantic salmon SHK-1 cells with bacterium Piscirickettsia salmonis”

BMC Veterinary Research ◽

10.1186/s12917-021-02853-6 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Rodrigo Díaz ◽

José Troncoso ◽

Eva Jakob ◽

Stanko Skugor

Keyword(s):

Gene Expression ◽

Iron Deficiency ◽

Atlantic Salmon ◽

Bacterial Load ◽

Host Cells ◽

Immune Gene ◽

Immune Signaling ◽

Immune Effector ◽

Infected Cells ◽

Piscirickettsia Salmonis

Abstract Background Vertebrate hosts limit the availability of iron to microbial pathogens in order to nutritionally starve the invaders. The impact of iron deficiency induced by the iron chelator deferoxamine mesylate (DFO) was investigated in Atlantic salmon SHK-1 cells infected with the facultative intracellular bacterium Piscirickettsia salmonis. Results Effects of the DFO treatment and P. salmonis on SHK-1 cells were gaged by assessing cytopathic effects, bacterial load and activity, and gene expression profiles of eight immune biomarkers at 4- and 7-days post infection (dpi) in the control group, groups receiving single treatments (DFO or P. salmonis) and their combination. The chelator appears to be well-tolerated by host cells, while it had a negative impact on the number of bacterial cells and associated cytotoxicity. DFO alone had minor effects on gene expression of SHK-1 cells, including an early activation of IL-1β at 4 dpi. In contrast to few moderate changes induced by single treatments (either infection or chelator), most genes had highest upregulation in the infected groups receiving DFO. The mildest induction of hepcidin-1 (antimicrobial peptide precursor and regulator of iron homeostasis) was observed in cells exposed to DFO alone, followed by P. salmonis infected cells while the addition of DFO to infected cells further increased the mRNA abundance of this gene. Transcripts encoding TNF-α (immune signaling) and iNOS (immune effector) showed sustained increase at both time points in this group while cathelicidin-1 (immune effector) and IL-8 (immune signaling) were upregulated at 7 dpi. The stimulation of protective gene responses seen in infected cultures supplemented with DFO coincided with the reduction of bacterial load and activity (judged by the expression of P. salmonis 16S rRNA), and damage to cultured host cells. Conclusion The absence of immune gene activation under normal iron conditions suggests modulation of host responses by P. salmonis. The negative effect of iron deficiency on bacteria likely allowed host cells to respond in a more protective manner to the infection, further decreasing its progression. Presented findings encourage in vivo exploration of iron chelators as a promising strategy against piscirickettsiosis.

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Foliar application of 3‐hydroxy‐4‐pyridinone Fe‐chelate [Fe(mpp) 3 ] induces responses at the root level amending iron deficiency chlorosis in soybean

Physiologia Plantarum ◽

10.1111/ppl.13367 ◽

2021 ◽

Author(s):

Carla S. Santos ◽

Elsa Rodrigues ◽

Sofia Ferreira ◽

Tânia Moniz ◽

Andreia Leite ◽

...

Keyword(s):

Iron Deficiency ◽

Foliar Application ◽

Iron Deficiency Chlorosis

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MAPPING OF IRON AND ZINC QUANTITATIVE TRAIT LOCI IN SOYBEAN FOR ASSOCIATION TO IRON DEFICIENCY CHLOROSIS RESISTANCE

Journal of Plant Nutrition ◽

10.1080/01904167.2013.766804 ◽

2013 ◽

Vol 36 (14) ◽

pp. 2132-2153 ◽

Cited By ~ 15

Author(s):

Keith E. King ◽

Gregory A. Peiffer ◽

Manju Reddy ◽

Nick Lauter ◽

Shun Fu Lin ◽

...

Keyword(s):

Quantitative Trait Loci ◽

Iron Deficiency ◽

Quantitative Trait ◽

Iron Deficiency Chlorosis ◽

Trait Loci ◽

Iron And Zinc ◽

Chlorosis Resistance

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Global impacts of chromosomal imbalance on gene expression in Arabidopsis and other taxa

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1807796115 ◽

2018 ◽

Vol 115 (48) ◽

pp. E11321-E11330 ◽

Cited By ~ 11

Author(s):

Jie Hou ◽

Xiaowen Shi ◽

Chen Chen ◽

Md. Soliman Islam ◽

Adam F. Johnson ◽

...

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Transcription Factors ◽

Leaf Tissue ◽

Global Gene Expression ◽

Published Data ◽

Chromosomal Imbalance ◽

Regulatory Processes ◽

Expression Of Genes ◽

Global Impacts

Changes in dosage of part of the genome (aneuploidy) have long been known to produce much more severe phenotypic consequences than changes in the number of whole genomes (ploidy). To examine the basis of these differences, global gene expression in mature leaf tissue for all five trisomies and in diploids, triploids, and tetraploids of Arabidopsis thaliana was studied. The trisomies displayed a greater spread of expression modulation than the ploidy series. In general, expression of genes on the varied chromosome ranged from compensation to dosage effect, whereas genes from the remainder of the genome ranged from no effect to reduced expression approaching the inverse level of chromosomal imbalance (2/3). Genome-wide DNA methylation was examined in each genotype and found to shift most prominently with trisomy 4 but otherwise exhibited little change, indicating that genetic imbalance is generally mechanistically unrelated to DNA methylation. Independent analysis of gene functional classes demonstrated that ribosomal, proteasomal, and gene body methylated genes were less modulated compared with all classes of genes, whereas transcription factors, signal transduction components, and organelle-targeted protein genes were more tightly inversely affected. Comparing transcription factors and their targets in the trisomies and in expression networks revealed considerable discordance, illustrating that altered regulatory stoichiometry is a major contributor to genetic imbalance. Reanalysis of published data on gene expression in disomic yeast and trisomic mouse cells detected similar stoichiometric effects across broad phylogenetic taxa, and indicated that these effects reflect normal gene regulatory processes.

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