Effect of Heat Stress on Some Physiological and Anatomical Characteristics of Rice (Oryza sativa L.) cv. KDML105 Callus and Seedling

Abstract

Global warming is a serious problem, with significant negative impacts on agricultural productivity. To better understand plant anatomical adaptation mechanisms as responses to heat stress, improved basic knowledge is required. This research studied the physiological and anatomical responses of Khao Dawk Mali 105 (KDML105) to artificial heat stress. Dehusked seeds were sterilized and cultured on Murashige and Skoog (MS) medium, supplemented with 3 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D) for callus induction. The cultures were maintained at 25 °C and 35 °C for 4 weeks, while the other culture was treated with heat shock at 42 °C for 1 week before further incubation at 25 °C for 3 weeks. Results revealed that elevated temperatures (35 °C and 42 °C) adversely impacted seedling growth. Plant height, root length, leaf number per plant, fresh and dry weight, chlorophyll a, chlorophyll b and total chlorophyll content decreased after heat stress treatment, while malondialdehyde (MDA) and electrolyte leakage percentage significantly increased, compared to the control. Heat stress induced ROS accumulation, leading to lipid peroxidation and membrane instability. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) results also confirmed negative correlations between MDA, electrolyte leakage and other parameters. MDA content and electrolyte leakage are effective indicators of heat stress in rice. Surface anatomical responses of rice seedlings to heat stress were studied but significant alterations were not observed, and heat stress had no significant negative effects on KDML105 calli. Size and mass of calli increased because heat stress stimulated gene expression that induced thermotolerance. Our results provide useful information for rice breeding and heat stress tolerance programs to benefit long-term global food security.

BcWRKY22 Activates BcCAT2 to Enhance Catalase (CAT) Activity and Reduce Hydrogen Peroxide (H2O2) Accumulation, Promoting Thermotolerance in Non-Heading Chinese Cabbage (Brassica campestris ssp. chinensis)

“…Given their active roles in enhancing heat tolerance mechanisms within plants, it is plausible that the increased expression of these genes may contribute to an overall improvement in thermal stress resistance [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ]. At the same time, the MDA content, H 2 O 2 content, and CAT enzyme activity are also important indicators of heat resistance in plants [ 57 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 ]. The overexpression of BcWRKY22 in plants demonstrated an enhancement in heat resistance through the observed physiological changes.…”

Zinc Oxide Nanoparticles in Alleviation of Toxicity Induced by Heat Stress in Plants

“…Cells effectively avoid OH by sequestering the catalytic metals to metallochaperones. Plants exposed to varied degrees of heat stress suffer from a variety of physiological damages (Taratima et al, 2022). All biomolecules, including pigments, proteins, lipids, and DNA, as well as almost all cellular components, are potentially reactive with hydroxyl radicals (Sharma et al, 2012; Das and Roychoudhury, 2014).…”

Evaluation of Temperature Stress Under Different Hydroponic Systems on Growth and Saponin Content of <i>Talinum paniculatum</i> Gaertn. Cuttings

“…Heat stress in plants can reduce their growth, number, and root mass (Huang et al 2012) before impacting the growth of tissue above ground (Giri et al 2017). It also triggers the accumulation of Reactive Oxygen Species (ROS), causing lipid peroxidation followed by membrane instability or damage (Taratima et al 2022). The presence of lipid peroxidation products (such as MDA) and electrolyte leakage were identified as indicators of heat stress in rice (Taratima et al 2022).…”

“…It also triggers the accumulation of Reactive Oxygen Species (ROS), causing lipid peroxidation followed by membrane instability or damage (Taratima et al 2022). The presence of lipid peroxidation products (such as MDA) and electrolyte leakage were identified as indicators of heat stress in rice (Taratima et al 2022). Malondialdehyde (MDA) is widely used as a marker of free radical formation due to oxidative stress (El-Aal 2012).…”