Diversity of hydrogen sulfide concentration in plant:a little spark to start a prairie fire

The ubiquitous and versatile signal-transduction role of hydrogen sulfide (H2S)has been revealed in mammals and plants in recent years [1-5].It is very important to grasp the physiological concentrations of H2S in vivo because of its toxic characteristics at high concentrations.However,the reported data fail to reach an agreement owing to the use of different methods and technique limitations. In fact,this is a common problem for gasotransmitters.What is the exact boundary between the physiological and toxicological concentration?What is the accurate endogenous content?These problems have been plaguing us even though there are a great number of research papers that explore H2S signals.