A new hemoglobin gene from soybean: a role for hemoglobin in all plants.

Anderson, Carol; Jensen, Erik Appel; Llewellyn, Danny J.; Dennis, Elizabeth S.; Peacock, W. J.

doi:10.1073/pnas.93.12.5682

Cited by 148 publications

(107 citation statements)

References 32 publications

(24 reference statements)

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“…Non-symbiotic Hbs have been detected in plant organs by Northern blot [8], RT-PCR [11] and Western blot [28,9]. In this work we analyzed the expression of hbm and hbt genes in plant organs by evaluating the levels of Hb transcripts and proteins by RT-PCR and Western blot, respectively.…”

Section: Expression Analysis Of Hbm and Hbt Genes In Plant Organsmentioning

confidence: 99%

“…Apparently, the expression of non-symbiotic hb genes varies significantly, and the highest levels of expression were detected in metabolically active or stressed organs. For example, highest levels of non-symbiotic Hb transcripts were detected in soybean stems [8], which are metabolically active organs. In Arabidopsis, two hb genes were cloned and analyzed: ahb1 gene is expressed in roots and rosette leaves but overexpressed under hypoxic conditions, whereas ahb2 gene is expressed at low levels in rosette leaves but overexpressed at low temperatures [9].…”

Section: Introductionmentioning

confidence: 99%

“…Among flowering plants, genes coding for non-symbiotic Hbs were cloned from dicot and monocot species. In dicots, non-symbiotic Hbs were first detected in root nodules and roots of Parasponia [6], and roots of Trema tomentosa [7], and more recently non-symbiotic hb genes were cloned from a number of dicot plants, including soybean [8] and Arabidopsis [9]. Apparently, the expression of non-symbiotic hb genes varies significantly, and the highest levels of expression were detected in metabolically active or stressed organs.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Cloning and expression analysis of hemoglobin genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis)

Aréchaga-Ocampo

Saenz-Rivera

Sarath

et al. 2001

Biochimica et Biophysica Acta (BBA) - Gene Structure and Expres

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Section: Expression Analysis Of Hbm and Hbt Genes In Plant Organsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cloning and expression analysis of hemoglobin genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis)

Aréchaga-Ocampo

Saenz-Rivera

Sarath

et al. 2001

Biochimica et Biophysica Acta (BBA) - Gene Structure and Expres

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“…It is well documented that land plant hb genes are either up- or down-regulated by stress conditions 1, 52, 54, 79– 82 . Table 1 shows that Hb transcripts coexist in rice growing under cold, drought and salt stress conditions.…”

Section: Molecular Biology Of Rice Hemoglobinsmentioning

confidence: 99%

“…This evidence demonstrated that Lbs are plant Hbs and indicated that plant and animal Hbs evolved from a common ancestor more than 600 mya 6 . Subsequent work led to the identification of Lb-like (or symbiotic) Hbs in nodules of actinorhizal plants 44– 48 , purification of an Hb from the root nodules of the dicotyledonous non-legume Parasponia andersonii 49 , cloning and sequencing of an hb gene from the non-nodulating dicot Trema tomentosa 50, 51 and detection of Hbs in non-symbiotic organs from several land plants, including primitive bryophytes and evolved angiosperms 9, 18, 52– 54 . Until now three types of Hbs have been identified in land plants: the symbiotic Hbs, which include Lbs, that are specifically located within nodules of the N 2 -fixing land plants, and the non-symbiotic (nsHbs) and truncated (tHbs) Hbs, that are located within non-symbiotic and symbiotic organs of primitive and evolved land plants 9, 18 .…”

Section: Introductionmentioning

confidence: 99%

Rice (Oryza) hemoglobins

2014

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Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice ( Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a single copy of the thb gene exist in Oryza sativa var. indica and O. sativa var. japonica, Hb transcripts coexist in rice organs and Hb polypeptides exist in rice embryonic and vegetative organs and in the cytoplasm of differentiating cells. At the structural level, the crystal structure of rice Hb1 has been elucidated, and the structures of the other rice Hbs have been modeled. Kinetic analysis indicated that rice Hb1 and 2, and possibly rice Hb3 and 4, exhibit an extremely high affinity for O 2, whereas rice Hb5 and tHb possibly exhibit a low to moderate affinity for O 2. Based on the accumulated information on the properties of rice Hbs and data from the analysis of other plant and non-plant Hbs, it is likely that Hbs play a variety of roles in rice organs, including O 2-transport, O 2-sensing, NO-scavenging and redox-signaling. From an evolutionary perspective, an outline for the evolution of rice Hbs is available. Rice nshb and thb genes vertically evolved through different lineages, rice nsHbs evolved into clade I and clade II lineages and rice nshbs and thbs evolved under the effect of neutral selection. This review also reveals lacunae in our ability to completely understand rice Hbs. Primary lacunae are the absence of experimental information about the precise functions of rice Hbs, the properties of modeled rice Hbs and the cis-elements and trans-acting factors that regulate the expression of rice hb genes, and the partial understanding of the evolution of rice Hbs.

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Review: Correlations between oxygen affinity and sequence classifications of plant hemoglobins

et al. 2009

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Plants express three phylogenetic classes of hemoglobins (Hb) based on sequence analyses. Class 1 and 2 Hbs are full-length globins with the classical eight helix Mb-like fold, whereas Class 3 plant Hbs resemble the truncated globins found in bacteria. With the exception of the specialized leghemoglobins, the physiological functions of these plant hemoglobins remain unknown. We have reviewed and, in some cases, measured new oxygen binding properties of a large number of Class 1 and 2 plant nonsymbiotic Hbs and leghemoglobins. We found that sequence classification correlates with distinct extents of hexacoordination with the distal histidine and markedly different overall oxygen affinities and association and dissociation rate constants. These results suggest strong selective pressure for the evolution of distinct physiological functions. The leghemoglobins evolved from the Class 2 globins and show no hexacoordination, very high rates of O(2) binding ( approximately 250 muM(-1) s(-1)), moderately high rates of O(2) dissociation ( approximately 5-15 s(-1)), and high oxygen affinity (K(d) or P(50) approximately 50 nM). These properties both facilitate O(2) diffusion to respiring N(2) fixing bacteria and reduce O(2) tension in the root nodules of legumes. The Class 1 plant Hbs show weak hexacoordination (K(HisE7) approximately 2), moderate rates of O(2) binding ( approximately 25 muM(-1) s(-1)), very small rates of O(2) dissociation ( approximately 0.16 s(-1)), and remarkably high O(2) affinities (P(50) approximately 2 nM), suggesting a function involving O(2) and nitric oxide (NO) scavenging. The Class 2 Hbs exhibit strong hexacoordination (K(HisE7) approximately 100), low rates of O(2) binding ( approximately 1 muM(-1) s(-1)), moderately low O(2) dissociation rate constants ( approximately 1 s(-1)), and moderate, Mb-like O(2) affinities (P(50) approximately 340 nM), perhaps suggesting a sensing role for sustained low, micromolar levels of oxygen.

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A new hemoglobin gene from soybean: a role for hemoglobin in all plants.

Cited by 148 publications

References 32 publications

Cloning and expression analysis of hemoglobin genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis)

Cloning and expression analysis of hemoglobin genes from maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis)

Rice (Oryza) hemoglobins

Review: Correlations between oxygen affinity and sequence classifications of plant hemoglobins

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