Hemoglobin as a probe for estimation of nitric oxide emission from plant tissues

Background Plant roots contribute significant amount of nitric oxide (NO) in the rhizosphere as a component of NO in the ecosystem. Various pharmacological investigations on NO research in plants seek to quench endogenous NO by using externally applied NO quenchers, mainly 2-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) and its more soluble form-carboxy-PTIO (cPTIO). Owing to serious limitations in its application cPTIO is no more a desired compound for such applications.