Haemoglobin modulates salicylate and jasmonate/ethylene-mediated resistance mechanisms against pathogens

• Published in: Journal of experimental botany 2012-07, Vol.63 (12), p.4375-4387
• Main Authors: Mur, Luis A. J, Sivakumaran, Anushen, Mandon, Julien, Cristescu, Simona M, Harren, Frans J. M, Hebelstrup, Kim H
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - immunology; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Assembly lines; Biological and medical sciences; Botrytis; Botrytis - growth & development; Botrytis - physiology; Botrytis cinerea; Cell death; Cyclopentanes - analysis; Cyclopentanes - metabolism; Down-Regulation - genetics; ethylene; Ethylenes - analysis; Ethylenes - metabolism; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Gene Expression Regulation, Plant - genetics; gene overexpression; hemoglobin; Hemoglobins; Hemoglobins - genetics; Hemoglobins - metabolism; Host-Pathogen Interactions; Inoculation; jasmonic acid; Lesions; mutants; Mutation; nitric oxide; Nitric Oxide - analysis; Nitric Oxide - metabolism; Oxides; Oxylipins - analysis; Oxylipins - metabolism; Pathogens; pathovars; Phenotype; Phenotypes; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Growth Regulators - analysis; Plant Growth Regulators - metabolism; Plant Immunity - genetics; Plant Leaves - genetics; Plant Leaves - immunology; Plant Leaves - physiology; Plant physiology and development; Plants; Plants, Genetically Modified; Pseudomonas syringae; Pseudomonas syringae - growth & development; Pseudomonas syringae - physiology; quantitative polymerase chain reaction; RESEARCH PAPER; resistance mechanisms; Salicylic Acid - analysis; Salicylic Acid - metabolism; tomatoes
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ers116

Nitric oxide (NO) plays a role in defence against hemibiotrophic pathogens mediated by salicylate (SA) and also necrotrophic pathogens influenced by jasmonate/ethylene (JA/Et). This study examined how NO-oxidizing haemoglobins (Hb) encoded by GLB1, GLB2, and GLB3 in Arabidopsis could influence both defence pathways. The impact of Hb on responses to the hemibiotrophic Pseudomonas syringae pathovar tomato (Pst) AvrRpm1 and the necrotrophic Botrytis cinerea were investigated using glb1, glb2, and glb3 mutant lines and also CaMV 35S GLB1 and GLB2 overexpression lines. In glb1, but not glb2 and glb3, increased resistance was observed to both pathogens but was compromised in the 35S-GLB1. A quantum cascade laser-based sensor measured elevated NO production in glb1 infected with Pst AvrRpm1 and B. cinerea, which was reduced in 35S-GLB1 compared to Col-0. SA accumulation was increased in glb1 and reduced in 35S-GLB1 compared to controls following attack by Pst AvrRpm1. Similarly, JA and Et levels were increased in glb1 but decreased in 35S-GLB1 in response to attack by B. cinerea. Quantitative PCR assays indicated reduced GLB1 expression during challenge with either pathogen, thus this may elevate NO concentration and promote a wide-ranging defence against pathogens.