Interaction between Nitric Oxide and Hydrogen Sulfide in Abiotic Stress Challenged Plants

Nitric oxide (NO) and hydrogen sulfide (H2S) are two versatile gaseous molecules which play myriad roles in the growth and development of plants. They play an important role in signal transduction process in plants exposed to various environmental stresses. Signal transduction and various antioxidant strategies are vital for the management of abiotic stress imposed alterations in plants. These two secondary messengers neutralize the cell perturbations caused by stresstriggered over produced reactive oxygen species. Study of crosstalk between NO and H2S reveals the functional importance of proteins regulated during Snitrosylation and S-sulfhydration respectively, the two major signal-dependent post-translational protein modifications. Also, NO and H2S decrease the toxic impacts of reactive species by triggering the signal transduction process, enhancing antioxidant enzymes, stimulating other signaling molecules and regulating the transcript levels of different stress-responsive genes. This review mainly emphasizes on the roles of NO and H2S in responses of plants to abiotic stresses and reveals the crosstalk involving NO and H2S in stress tolerance mechanisms.