Quantification of hydrogen sulfide concentration using methylene blue and 5,5'-dithiobis(2-nitrobenzoic acid) methods in plants.

Hydrogen sulfide (H2S) has long been considered as a phytotoxin but, nowadays, as a novel signaling molecule at low concentration in plants, which is involved in plant growth, development, and the acquisition of tolerance to abiotic and biotic stresses. H2S is commonly found only in very small amounts in most biological systems. To further understand H2S functions, accurate measurement of H2S concentration in plants is very important. In this chapter, quantificational methods of H2S in plant tissues, namely, methylene blue (MB) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) methods, are introduced; the former has higher sensitivity than that of the latter, and the determination limits of MB and DTNB methods are 1.5×10(-7)M (0.005 μg/ml) and 3.7×10(-6)M (0.13 μg/ml), respectively, hoping to stimulate more research into H2S signal molecule in plants.