Journal Article

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

Younis, Abeer Abdelrazk, Mansour, Mohamed Magdy Fahim

2024

Overview

Background Salinity is one major abiotic stress affecting photosynthesis, plant growth, and development, resulting in low-input crops. Although photosynthesis underlies the substantial productivity and biomass storage of crop yield, the response of the sunflower photosynthetic machinery to salinity imposition and how H 2 S mitigates the salinity-induced photosynthetic injury remains largely unclear. Seed priming with 0.5 mM NaHS, as a donor of H 2 S, was adopted to analyze this issue under NaCl stress. Primed and nonprime seeds were established in nonsaline soil irrigated with tape water for 14 d, and then the seedlings were exposed to 150 mM NaCl for 7 d under controlled growth conditions. Results Salinity stress significantly harmed plant growth, photosynthetic parameters, the structural integrity of chloroplasts, and mesophyll cells. H 2 S priming improved the growth parameters, relative water content, stomatal density and aperture, photosynthetic pigments, photochemical efficiency of PSII, photosynthetic performance, soluble sugar as well as soluble protein contents while reducing proline and ABA under salinity. H 2 S also boosted the transcriptional level of ribulose 1,5-bisphosphate carboxylase small subunit gene ( HaRBCS ). Further, the transmission electron microscope showed that under H 2 S priming and salinity stress, mesophyll cells maintained their cell membrane integrity and integrated chloroplasts with well-developed thylakoid membranes. Conclusion The results underscore the importance of H 2 S priming in maintaining photochemical efficiency, Rubisco activity, and preserving the chloroplast structure which participates in salinity stress adaptation, and possibly sunflower productivity under salinity imposition. This underpins retaining and minimizing the injury to the photosynthetic machinery to be a crucial trait in response of sunflower to salinity stress.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abiotic stress / Abiotic stress tolerance in plants / Abscisic acid / Agricultural production / Agricultural research / Agriculture / biomass / Biomedical and Life Sciences / Carotenoids / Cell membranes / Chlorophyll / Chloroplast / Chloroplasts / Chloroplasts - metabolism / Crop yield / Crop yields / Efficiency / Environmental aspects / Ethylenediaminetetraacetic acid / Flowers & plants / Food security / genes / Growth conditions / Helianthus / Helianthus - drug effects / Helianthus - growth & development / Helianthus - metabolism / Helianthus - physiology / Helianthus annuus / hydrogen / Hydrogen sulfide / Hydrogen Sulfide - metabolism / Leaves / Life Sciences / Mesophyll / Metabolism / Moisture content / Oilseeds / Osmoregulation / Parameters / Photochemicals / photochemistry / Photosynthesis / Photosynthesis - drug effects / Photosynthetic pigments / Photosystem II / Physiological aspects / Physiology / Plant growth / Plant resistance / Plant Sciences / Priming / Productivity / Proline / Ribulose-bisphosphate carboxylase / Rubisco / Salinity / Salinity effects / Salt Stress / Seedlings / Seedlings - drug effects / Seedlings - growth & development / Seedlings - physiology / Seeds / Sodium chloride / soil / Soils, Salts in / Stomata / Structural integrity / sugars / Sunflower / Sunflowers / Sustainable agriculture / Thylakoid membranes / thylakoids / transcription (genetics) / Transmission electron microscopes / Tree Biology / Water content / Water-electrolyte balance (Physiology)