Hydrogen sulfide as a potent regulator of plant responses to abiotic stress factors

Abstract

Adverse abiotic stress conditions such as drought, salinity, cold, heat and heavy metal toxicity are considered to be major concerns of the agricultural industry worldwide, as they can affect crop yield and quality, as well as agricultural sustainability in general. Priming of crop plants for more rapid and robust activation of defence reactions offers a means for the effi cient alleviation of the devastating effects induced as a result of exposure to such adverse environmental conditions. Accumulating reports over the recent years postulate a role for hydrogen sulfi de (H2S) as an emerging signaling molecule involved in the regulation of physiological processes in plants. In this chapter, we provide a brief overview of recent literature concerning H2S biosynthesis and regulation within the plant cell, as well as its involvement in a series of plant physiological processes. Furthermore, the H2S-mediated enhancement of plant tolerance upon exposure to drought, salt, heavy metal and heat stress is highlighted; particular emphasis is given on the priming effect of H2S on antioxidant capacity, redox regulation and signaling, and transcriptional regulation of specific cellular defence components. This up-to-date overview proposes a role for H2S in plant priming, further supporting the notion that H2S is a key player in plant’s tolerance to abiotic stress factors, possibly acting in cross-talk with other secondary messengers.