Journal of Plant Production and Sustainability DOI: https://doi.org/10.63072/jpps.25009 Volume 1, Issue 2, 2025, Pages 16-37 ISSN: 3135-7423 (Online) https://jplantps.org/ RESEARCH PAPER
Evaluating the effect of exogenous application of salicylic acid on heat stress tolerance in wheat (Triticum aestivum L.) Syeda Gulshan Batool1, Abdul Wahid1, Aysha Kiran1, Zahid Abbas Malik2* and Zeshan Hassan2 1
Department of Botany, Faculty of Sciences, University of Agriculture, Faisalabad, Pakistan Department of Plant Production & Biotechnology, University of Layyah, 31200, Layyah, Pakistan
2
*Corresponding author’s e-mail: zahidnibge@yahoo.com Abstract Heat stress is a major abiotic constraint that impairs photosynthesis, disrupt cellular homeostasis, and reduce grain yield in wheat. Salicylic acid (SA), an important signalling molecule, enhances tolerance to several abiotic stresses, but its role in improving wheat performance under heat stress remains insufficiently explored. Therefore this research study was was conducted to evaluate the effect of exogenous salicylic acid (SA; 5 mM) on heat stress tolerance in wheat (Triticum aestivum L., cv. FSD-2002). Plants were exposed to >32 °C after 45 days of seedling growth and treated with SA as a foliar spray, soil supplementation, or both. ANOVA showed significant (p < 0.05) improvements in all growth and yield traits. Under control conditions, shoot and root lengths increased from 59 and 33 cm in untreated plants to 87 and 52 cm with combined SA treatment, while under heat stress they rose from 49 and 26 cm to 71 and 45 cm, respectively. Shoot and root fresh weights improved from 5.6 and 1.5 g to 8.7 and 3.1 g under control, and from 4.5 and 1.3 g to 7.7 and
2.2 g under stress. SA enhanced physiological traits, raising SPAD values from 34.2 to 46.1 (control) and 27.5 to 39.4 (stress), and leaf area from 21.5 to 35.6 cm² and 16.4 to 29.3 cm², respectively. Yield traits improved markedly: spikes from 8 to 15, spikelets from 20 to 35, grains per spike from 35 to 52, and 1000-grain weight from 35 to 59 g under control; corresponding stressed values rose from 5 to 11 spikes, 12 to 26 spikelets, 22 to 38 grains, and 30 to 51 g. Mineral nutrition was enhanced, with shoot calcium increasing from 8.1 to 11.5 mg/g DW (control) and 7.2 to 9.8 mg/g DW (stress), sulphate from 6.9 to 11.1 and 6.1 to 9.6 µg/g DW, and phosphate from 7.5 to 10.3 and 7.0 to 9.7 µg/g DW. These findings demonstrate that SA plays a key role in strengthening heat stress tolerance in wheat by sustaining biomass production, improving mineral nutrition, and preserving chlorophyll and photosynthetic capacity under thermal stress. © 2025 The Author(s) Keywords: Chlorophyll retention, Heat stress, Mineral nutrition, Physiological tolerance, Salicylic acid, Wheat, Yield attributes
Citation: Batool, S. G., Wahid, A., Kiran, A., Malik, Z. A., & Hassan, Z. (2025). Evaluating the effect of exogenous application of salicylic acid on heat stress tolerance in wheat (Triticum aestivum L.). Journal of Plant Production and Sustainability, 1(2), 16–37. https://doi.org/10.63072/jpps.25009
Introduction Wheat (Triticum aestivum L.) is one of the world’s most important staple cereals, providing a major share of daily caloric and protein intake for a large proportion of the global population (Iqbal et al., 2018; Abbas & Shafique, 2019; Mehmood et al., 2020). Its adaptability to diverse agro-climatic regions and central role in food security make the improvement of its productivity a continual priority in agricultural research. Ensuring stable wheat production, particularly under increasing environmental stresses such as heat, remains essential for sustaining global food systems and supporting rural livelihoods (Alamgeer et al., 2022; Dinsa & Balcha, 2024). Among major abiotic stress factors, heat stress has gained more attention due to its irreversible damages to plant growth and development (Battisti & Naylor, 2009). The environmental conditions are constantly changing, that
causes an increase in average temperature that is very damaging to agricultural crops (Noroz et al., 2021; Omokhafe et al., 2024). The atmospheric temperature is continuously increasing up to 0.27 oC per decade (Zhao et al., 2017; Raza et al., 2019; Malhi et al., 2021; Forster et al., 2025). Heat shock is a sudden extreme high temperature (>32 °C) for short period of time (three-four days), while chronic heat stress consists of moderate temperature (20-30°C) for a longer duration (Corbellini et al., 1997). Heat stress causes many damages during reproductive stages (Larkindale & Knight, 2002) and disrupts ions and osmotic homeostasis at cellular levels. It affects photosynthesis and alters those genes that maintain protein homeostasis required for stability of deoxyribonucleic acid (DNA) (Abdelrahman et al., 2017). Heat stress often affects grain yield, biomass production, and thousand kernel weights (Barma, 2005; Rahman, 2009). The rate of plant metabolic processes, the production of fruits and grain are mainly influenced by temperature (Tandel et al., 2025).