Plant hemoglobins: important players at the crossroads between oxygen and nitric oxide.
Plant hemoglobins constitute a diverse group of hemeproteins and evolutionarily belong to three different classes. Class 1 hemoglobins possess an extremely high affinity to oxygen and their main function consists in scavenging of nitric oxide (NO) at very low oxygen levels. Class 2 hemoglobins have a lower oxygen affinity and they facilitate oxygen supply to developing tissues. Symbiotic hemoglobins in nodules have mostly evolved from class 2 hemoglobins. Class 3 hemoglobins are truncated and represent a clade with a very low similarity to class 1 and 2 hemoglobins. They may regulate oxygen delivery at high O(2) concentrations. Depending on their physical properties, hemoglobins belong either to hexacoordinate non-symbiotic or pentacoordinate symbiotic groups. Plant hemoglobins are plausible targets for improving resistance to multiple stresses.
Department of Plant Physiology, University of Rostock, Rostock, Germany.
Kapuganti J
KJ
Gupta
Kim H
KH
Hebelstrup
Luis A J
LA
Mur
Abir U
AU
Igamberdiev
D000818:Animals; D006454:Hemoglobins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D013559:Symbiosis
D006454:Hemoglobins; D010940:Plant Proteins; D009569:Nitric Oxide; D010100:Oxygen