Hydrogen sulfide: An emerging signaling molecule regulating drought stress response in plants

Abstract

Hydrogen sulfide (H 2 S) is a small, reactive signaling molecule that is produced within chloroplasts of plant cells as an intermediate in the assimilatory sulfate reduction pathway by the enzyme sulfite reductase. In addition, H 2 S is also produced in cytosol and mitochondria by desulfhydration of L-cysteine catalyzed by L-cysteine desulfhydrase (DES1) in the cytosol and from β-cyanoalanine in mitochondria, in a reaction catalyzed by β-cyano-Ala synthase C1 (CAS-C1). H 2 S exerts its numerous biological functions by post-translational modification involving oxidation of cysteine residues (RSH) to persulfides (RSSH). At lower concentrations (10-1000 μmol L À1 ), H 2 S shows huge agricultural potential as it increases the germination rate, the size, fresh weight, and ultimately the crop yield. It is also involved in abiotic stress response against drought, salinity, high temperature, and heavy metals. H 2 S donor, for example, sodium hydrosulfide (NaHS), has been exogenously applied on plants by various researchers to provide drought stress tolerance. Exogenous application results in the accumulation of polyamines, sugars, glycine betaine, and enhancement of the antioxidant enzyme activities in response to drought-induced osmotic and oxidative stress, thus, providing stress adaptation to plants. At the biochemical level, administration of H 2 S donors reduces malondialdehyde content and lipoxygenase activity to maintain the cell integrity, causes abscisic acid-mediated stomatal closure to prevent water loss through transpiration, and accelerates the photosystem II repair cycle. Here, we review the crosstalk of H 2 S with secondary messengers and phytohormones towards the regulation of drought stress response and emphasize various approaches that can be addressed to strengthen research in this area. | INTRODUCTIONDrought-induced osmotic stress restricts the overall growth of plants due to the low rate of water absorption by roots and the high rate of transpiration (Blum, 1996). In addition to this, water deficiency leads to a significant reduction in leaf cell turgor, which ultimately causes a restriction in the expansion of cells, decreases leaf area, and rate of photosynthesis, thereby inhibiting the buildup of biomass (Chaves et al., 2003;Raja et al., 2020). Drought causes an imbalance between light capture and its utilization which results in the accumulation of reactive oxygen species (ROS) in the chloroplast, leading to disorganization of thylakoid membranes (Hussain et al., 2018;Kosar et al., 2020;Ladjal et al., 2000) and inactivation of photosystem II (PS II) by inhibition, both in the flow of electrons and electron transfer from the reduced plastoquinone (PQ) pool to the PS I reaction center (Dąbrowski et al., 2019;Giardi et al., 1996), as a consequence of oxidative stress. Net photosynthetic rate, chlorophyll fluorescence, and antioxidant activities in soybean were also influenced by water deficit (Iqbal et al., 2019). Several measures have evolved in plants to sustain photosynthetic activity by repairin...

A NAC Transcription Factor from ‘Sea Rice 86′ Enhances Salt Tolerance by Promoting Hydrogen Sulfide Production in Rice Seedlings

“…Hydrogen sulfide (H 2 S) is the third gaseous signal molecule that is excavated after nitric oxide and carbon monoxide in animals, and is closely related to body health [ 59 ]. Recent studies have shown that, in plant systems, the application of exogenous H 2 S donors can significantly enhance the tolerance of plants to abiotic stresses, such as drought, high salinity, and toxic heavy metals [ 45 , 60 , 61 ]. More and more attention has been paid to the mechanism by which the signaling molecule H 2 S in the plant system regulates other signaling pathways involved in various abiotic stress responses [ 62 ].…”

Hydrogen sulfide‐mediated mitigation and its integrated signaling crosstalk during salinity stress

“…Besides, H 2 S decrease the impact of harsh environment on plants (Huang et al, 2021; Liu & Xue, 2021; Raza et al, 2021; Zhang et al, 2021). In plants, H 2 S alleviates many abiotic stresses, namely, heavy metals (Chen et al, 2018; Dawood et al, 2012; Sun et al, 2013; Zhang et al, 2010a), drought (Jin et al, 2011; Thakur & Anand, 2021; Zhang et al, 2010b), salt (Christou et al, 2013), chilling (Zhang et al, 2020), heat (Li et al, 2012a, 2013), and also offer biotic stress resistance (Liu & Xue, 2021; Shi et al, 2015). The improvement of ROS homeostasis, antioxidant system, K + /Na + ratio, and photosynthesis are mainly reported for H 2 S‐mediated tolerance in plants.…”

“…This was observed for salt stress ( M . sativa ; Wang et al, 2012a), osmotic and drought stresses ( Ipomoea batatas ; Zhang et al, 2009b; Glycine max ; Zhang et al, 2010b; Arabidopsis thaliana ; Jin et al, 2011, Thakur & Anand, 2021), heavy metal stress ( M . sativa ; Li et al, 2012b; C .…”

Hydrogen sulphide‐mediated alleviation and its interplay with other signalling molecules during temperature stress

“…Hydrogen sulphide provides relief from many stresses, e.g. drought (Thakur & Anand 2021), salinity (Srivastava et al 2022), heat (Iqbal et al 2021a), chilling (Zhang et al 2020), heavy metals (Luo et al 2020), water-logging (Xiao et al 2020) and biotic stresses (Vojtovi c et al 2021). Further, many studies have focused on the role of H 2 S for stress mitigation (Li et (Bita & Gerats, 2013;Mishra et al 2017).…”

“…Hydrogen sulphide provides relief from many stresses, e.g . drought (Thakur & Anand 2021), salinity (Srivastava et al . 2022), heat (Iqbal et al .…”