Hydrogen sulfide signaling in plant response to temperature stress

Abstract

For the past 300 years, hydrogen sulfide (H2S) has been considered a toxic gas. Nowadays, it has been found to be a novel signaling molecule in plants involved in the regulation of cellular metabolism, seed germination, plant growth, development, and response to environmental stresses, including high temperature (HT) and low temperature (LT). As a signaling molecule, H2S can be actively synthesized and degraded in the cytosol, chloroplasts, and mitochondria of plant cells by enzymatic and non-enzymatic pathways to maintain homeostasis. To date, plant receptors for H2S have not been found. It usually exerts physiological functions through the persulfidation of target proteins. In the past 10 years, H2S signaling in plants has gained much attention. Therefore, in this review, based on that same attention, H2S homeostasis, protein persulfidation, and the signaling role of H2S in plant response to HT and LT stress were summarized. Also, the common mechanisms of H2S-induced HT and LT tolerance in plants were updated. These mechanisms involve restoration of biomembrane integrity, synthesis of stress proteins, enhancement of the antioxidant system and methylglyoxal (MG) detoxification system, improvement of the water homeostasis system, and reestablishment of Ca2+ homeostasis and acid-base balance. These updates lay the foundation for further understanding the physiological functions of H2S and acquiring temperature-stress-resistant crops to develop sustainable food and agriculture.

Hydrogen sulfide-mitigated salinity stress impact in sunflower seedlings was associated with improved photosynthesis performance and osmoregulation

“…The reduction in growth parameters and the higher R/S ratio were also reported in different crop species in response to saline conditions [ 40 – 44 ]. On the other hand, the mitigative effect of H 2 S on salinity-induced growth reduction most probably is interpreted as H 2 S modulation of ion hemostasis, elevation of osmolyte levels (total soluble proteins and total soluble sugars observed in this study), signaling molecule role, and scavenging of ROS under saline imposition [ 34 , 35 , 45 – 48 ]. Reduced toxic ions and elevated beneficial ones as well as ROS detoxification by H 2 S priming under saline conditions have been reported as adaptive mechanisms for sunflower salinity tolerance [ 35 ].…”

“…Our finding is consistent with the results of Lisjak et al [ 57 , 58 ], who report H 2 S promotion of stomata to open by reducing ABA accumulation in Arabidopsis thaliana . We also propose that stomatal aperture enhancement by H 2 S may increase CO 2 availability in the mesophyll cells as well as water homeostasis, and thereby stimulate the photosynthesis efficiency observed in this study [ 30 , 34 , 45 , 59 ].…”

“…Also, the disappearance of grana observed in this study may cause a reduction in F m and F v /F m leading to the downregulation of PSII activity [ 18 , 71 ]. H 2 S priming, however, enhanced photosynthetic pigment content and preserved chloroplast ultrastructure, suggestive of H 2 S role as a signaling molecule stimulating the chloroplast biogenesis and increasing the quantity of grana lamellae [ 72 ], repairing the biomembrane [ 34 ], enhancing the antioxidants, and lowering Na + uptake and translocation [ 35 ], which ultimately protected the thylakoid membranes and boosted the photosynthetic capacity of NaCl-challenged sunflower plants. Similarly, other published works reported H 2 S promotion of chlorophyll contents and photosynthetic capacity in a variety of plants [ 73 – 75 ].…”

“…Similarly, other published works reported H 2 S promotion of chlorophyll contents and photosynthetic capacity in a variety of plants [ 73 – 75 ]. In the same trend, H 2 S-triggered carotenoid concentration can be explained by the contention that H 2 S upregulated the expression levels of the carotenoid-related genes and thus their biosynthesis enzyme activities [ 70 ] as well as enhancing osmoregulators under stress [ 34 ]. It is noteworthy that Zhao et al [ 70 ] showed the carotenoid accumulation increase was associated with improved salinity tolerance in carrots as the carotenoids are essential components of the photosynthetic antenna and reaction center complexes, as precursors in signaling pathways, responsible for antioxidant defense, and other protective roles that help plants cope with abiotic stress.…”

“…H 2 S, an emerging gaseous signaling molecule in plants, plays a pivotal role in regulating various physiological, biochemical, and developmental processes, including seed germination, plant growth, and development, regulates stomatal apertures, promotes photosynthetic activity, enhances plant’s resistance to abiotic stresses [ 30 – 33 ]. H 2 S as a signaling molecule in plants regulates these processes through crosstalk with other signaling molecules resulting in the repairing of biomembranes and denatured proteins as well under stress [ 34 ]. As a result, we hypothesized that the H 2 S priming to sunflower seeds could boost stomatal mechanics and protect the stability of chloroplast structure and photosynthetic pigments, which in turn, could enhance photosynthetic efficiency.…”