Interactive effects of hydrogen sulphide and silicon enhance drought and heat tolerance by modulating hormones, antioxidant defence enzymes and redox status in barley (Hordeum vulgare L.)

Abstract

Recent changes in climate have reduced crop productivity throughout much of the world. Drought and heat stress, particularly in arid and semi‐arid regions, have seriously affected barley production. This study explored the separate and interactive effects of silicon (Si) and hydrogen sulphide (H2S) on plant growth and mitigation of the adverse effects of heat stress (DS) and drought stress (HS) in a barley pot experiment. The impacts of simultaneous DS + HS were more severe than individual stresses due to increased ROS production, malondialdehyde (MDA) content and higher electrolyte leakage (EL), thereby leading to reduced water, protein and photosynthetic pigment content. Exogenously applied Si and H2S alleviated the DS‐, HS‐ and DS + HS‐induced effects on barley by reducing ROS production, MDA and EL. A single application of H2S or Si + H2S increased plant biomass under all stress conditions, which can be ascribed to higher Si accumulation in barley shoots. A single application of Si or H2S significantly increased plant biomass. However, Si + H2S was the most effective treatment for metabolite accumulation and elevating activity of antioxidant enzymes to prevent toxicity from oxidative stress. This treatment also modulated osmolyte content, enhanced antioxidant activity and regulated the stress signalling‐related endogenous hormones, abscisic acid (ABA) and indole acetic acid (IAA). Exogenous treatments regulated endogenous H2S and Si and resulted in higher tolerance to individual and combined drought and heat stress in barley.

The Effect of Students’ Cognitive and Emotional Engagement on Students’ Academic Success and Academic Productivity

“…The majority of the definitions of cognitive engagement are drawn from two types of literature. One is their mental dedication to education, their desire to go above and beyond what is expected of them in school, and their demonstration that they embrace challenges; it is generally recognized as an important factor in determining the success of learning experiences (Batool et al, 2022Salameh et al, 2022;Tufail et al, 2022;Naz et al, 2022). This idea of cognitive involvement includes adaptability in problem-solving, a preference for diligence, and useful coping mechanisms in case of failure.…”

Emerging role of hydrogen sulphide as a signalling molecule in plant biology

“…Mfarrej et al (2022) studied the response to H 2 S and NO in wheat under waterlogging stress and reported that both treatments alleviate waterlogging stress in wheat genotypes and improve the accumulation of essential nutrients and photosynthetic attributes and also regulate expression of stress-related genes. Naz et al (2022) reported that exogenous application of silicon (Si) with H 2 S was more effective in mitigation of drought and heat stress by modulating hormones, antioxidant defence enzymes and redox status in barley (Hordeum vulgare L.). Siddiqui et al (2022) reported that H 2 S significantly protects the quality of banana fruits after harvest by inhibiting oxidative damage, rapid ripening and senescence; H 2 S delays chlorophyll degradation and suppresses ethylene and CO 2 production.…”

“…Naz et al . (2022) reported that exogenous application of silicon (Si) with H 2 S was more effective in mitigation of drought and heat stress by modulating hormones, antioxidant defence enzymes and redox status in barley ( Hordeum vulgare L.). Siddiqui et al .…”

Enzymatic and biochemical responses to high temperatures and drought stress during the reproductive stage in lentil (Lens Culinaris Medik.)

“…According to Wahid et al 19 , high temperatures can be accompanied by drought due to rapid water evaporation from the plant and soil surface. High temperature and drought stress have been studied in a variety of plant species, including wheat 20 , barley 21 , maize 22 , chickpea 23 , lentil 24 and soybean 25 . However, the combined effects of high temperatures and drought on plant growth, productivity and quality are more severe than the individual effects, with the reproductive phase being more vulnerable than the vegetative stage 26 .…”