The Essential Role of H2S-ABA Crosstalk in Maize Thermotolerance through the ROS-Scavenging System

Abstract

Hydrogen sulfide (H2S) and abscisic acid (ABA), as a signaling molecule and stress hormone, their crosstalk-induced thermotolerance in maize seedlings and its underlying mechanism were elusive. In this paper, H2S and ABA crosstalk as well as the underlying mechanism of crosstalk-induced thermotolerance in maize seedlings were investigated. The data show that endogenous levels of H2S and ABA in maize seedlings could be mutually induced by regulating their metabolic enzyme activity and gene expression under non-heat stress (non-HS) and HS conditions. Furthermore, H2S and ABA alone or in combination significantly increase thermotolerance in maize seedlings by improving the survival rate (SR) and mitigating biomembrane damage. Similarly, the activity of the reactive oxygen species (ROS)-scavenging system, including enzymatic antioxidants catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and superoxide dismutase (SOD), as well as the non-enzymatic antioxidants reduced ascorbic acid (AsA), carotenoids (CAR), flavone (FLA), and total phenols (TP), was enhanced by H2S and ABA alone or in combination in maize seedlings. Conversely, the ROS level (mainly hydrogen peroxide and superoxide radical) was weakened by H2S and ABA alone or in combination in maize seedlings under non-HS and HS conditions. These data imply that the ROS-scavenging system played an essential role in H2S-ABA crosstalk-induced thermotolerance in maize seedlings.

Metabolic and Functional Interactions of H2S and Sucrose in Maize Thermotolerance through Redox Homeodynamics

“…In recent years, substantial studies have reported that H 2 S as a signaling molecule modulates seed germination, stomatal movement, floral induction, organ senescence, and plant stress response [ 2 , 4 , 5 , 6 ]. Our studies also found that as a signaling molecule, H 2 S was able to increase maize thermotolerance, which is implicated in the signaling crosstalk of H 2 S with calcium, nitric oxide, methylglyocal, and abscisic acid [ 2 , 7 , 8 ]. However, whether H 2 S-promoted maize thermotolerance is related to sucrose signaling remains unclear.…”

“…In plants, H 2 S and SUC are key signaling molecules which regulate many kinds of stress responses, including heat stress [ 2 , 6 , 7 , 29 ]. However, whether crosstalk of H 2 S and SUC signaling exists in the formation of maize thermotolerance remains unclear.…”

“…A substantial number of studies have shown that heat stress can lead to multiple forms of damage, such as protein denaturation, biomembrane damage, osmotic stress, and oxidative stress [ 2 , 7 , 32 ]. Among these forms of damage, oxidative stress is a major determinant, which can further cause other damages [ 2 , 27 , 32 , 33 ].…”

“…Due to its multiple roles, global maize production and consumption is increasing year by year, with maize becoming a leading cereal crop [ 22 ]. Although maize is a temperature-loving crop, its growth and development, especially in the seedling stage, are sensitive to heat stress [ 7 , 23 , 24 , 25 , 26 ]. A 1 °C increase in average global temperature could lead to a reduction in maize yield by 7.4% [ 23 , 24 ].…”

Heat-Resistant Inbred Lines Coordinate the Heat Response Gene Expression Remarkably in Maize (Zea mays L.)

“…For instance, HS can result in oxidative damage due to the excessive accumulation of reactive oxygen species (ROS) [ 11 ]. The level of ROS within plant cells is strictly controlled by the ROS scavenging system to maintain ROS homeostasis which has been found to be positively correlated with maize thermotolerance [ 12 ]. In addition, heat shock proteins (HSPs), known as molecular chaperones, participate in a wide range of biological processes including HS [ 13 ].…”