Non-symbiotic plant haemoglobins modulate nitric oxide bioactivity

The broad chemistry of nitric oxide (NO) involves an array of interrelated redox forms with different chemical reactivities. It may have beneficial effects but unregulated NO production can lead to either apoptotic or necrotic cell death, depending on the severity of the damage. Hemoglobins are well known regulators of NO homeostasis. We found that non-symbiotic haemoglobin GLB1 from Arabidopsis thaliana detoxifies NO and GSNO, and limits NO emission when overexpressed in transgenic Arabidopsis plants.We therefore conclude that an important function of non-symbiotic haemoglobins is to detoxify NO