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. 2012:2012:pls004.
doi: 10.1093/aobpla/pls004. Epub 2012 Mar 2.

Non-symbiotic haemoglobins-What's happening beyond nitric oxide scavenging?

Robert D Hill  1
Affiliations

Non-symbiotic haemoglobins-What's happening beyond nitric oxide scavenging?

Robert D Hill. AoB Plants. 2012.

Abstract

Background and aims: Non-symbiotic haemoglobins have been an active research topic for over 30 years, during which time a considerable portfolio of knowledge has accumulated relative to their chemical and molecular properties, and their presence and mode of induction in plants. While progress has been made towards understanding their physiological role, there remain a number of unanswered questions with respect to their biological function. This review attempts to update recent progress in this area and to introduce a hypothesis as to how non-symbiotic haemoglobins might participate in regulating hormone signal transduction.

Principal results: Advances have been made towards understanding the structural nuances that explain some of the differences in ligand association characteristics of class 1 and class 2 non-symbiotic haemoglobins. Non-symbiotic haemoglobins have been found to function in seed development and germination, flowering, root development and differentiation, abiotic stress responses, pathogen invasion and symbiotic bacterial associations. Microarray analyses under various stress conditions yield uneven results relative to non-symbiotic haemoglobin expression. Increasing evidence of the role of nitric oxide (NO) in hormone responses and the known involvement of non-symbiotic haemoglobins in scavenging NO provide opportunities for fruitful research, particularly at the cellular level.

Conclusions: Circumstantial evidence suggests that non-symbiotic haemoglobins may have a critical function in the signal transduction pathways of auxin, ethylene, jasmonic acid, salicylic acid, cytokinin and abscisic acid. There is a strong need for research on haemoglobin gene expression at the cellular level relative to hormone signal transduction.

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Figures

Fig. 1
Fig. 1
The relationship between NO, hormones and biological function.
Fig. 2
Fig. 2
A schematic diagram of the eliciting agents and mode of action of non-symbiotic haemoglobins and NO in plants.
See this image and copyright information in PMC

References

    1. Abbruzzetti S, Grandi E, Bruno S, Faggiano S, Spyrakis F, Mozzarelli A, Cacciatori E, Dominici P, Viappiani C. Ligand migration in nonsymbiotic hemoglobin AHb1 from Arabidopsis thaliana. Journal of Physics and Chemistry B. 2007;111:12582–12590. - PubMed
    1. Ahlfors R, Brosche M, Kangasjarvi J. Ozone and nitric oxide interaction in Arabidopsis thaliana: a role for ethylene? Plant Signaling & Behavior. 2009;4:878–879. - PMC - PubMed
    1. Appleby CA. The origin and functions of haemoglobin in plants. Science Progress. 1992;76:365–398.
    1. Arechaga-Ocampo E, Saenz-Rivera J, Sarath G, Klucas RV, Arredondo-Peter R. Cloning and expression analysis of hemoglobin genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis) Biochimica et Biophysica Acta. 2001;1522:1–8. - PubMed
    1. Arredondo-Peter R, Hargrove MS, Sarath G, Moran JF, Lohrman J, Olson JS, Klucas RV. Rice hemoglobins: gene cloning, analysis and oxygen-binding kinetics of a recombinant protein synthesized in Escherichia coli. Plant Physiology. 1997;115:1259–1266. - PMC - PubMed