Effects of prohexadione calcium spraying during the booting stage on panicle traits, yield, and related physiological characteristics of rice under salt stress

Abstract

Prohexadione calcium (Pro-Ca), as a growth retardant, can effectively alleviate the damage of salt stress to plants. In order to explore the effects of NaCl stress on the physiological characteristics and panicle traits of rice plants as well as the alleviating effect of Pro-Ca at the booting stage, we performed pot experiments on two rice cultivars: conventional rice ‘Huanghuazhan’ and hybrid rice ‘Xiangliangyou900’. Rice plants were treated with 0.3% NaCl 48 hours after Pro-Ca (100 mg L−1) treatment to study the effects of Pro-Ca on the physiological characteristics of the leaves and panicles, as well as the panicle and yield traits of rice under salt stress. Our analysis indicated that NaCl treatment inhibited the morphological growth parameters and photosynthetic efficiency, destroyed the antioxidant defense systems of leaves and panicles, increased soluble protein and proline in both rice cultivars. Foliar application of Pro-Ca significantly increased the leaf area, uppermost internode length, panicle length, panicle weight, number of primary branches, number of grains per panicle, seed setting rate and yield under salt stress. Pro-Ca application significantly affected chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and apparent mesophyll conductance (AMC) in NaCl-treated rice cultivars compared with NaCl treatment alone. Moreover, Pro-Ca also increased ascorbic acid (AsA) content, enhanced superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity, and further increased the accumulation of soluble protein and proline in leaves and panicles. These results illustrated that foliar application of Pro-Ca at the booting stage could alleviate the damage caused by NaCl stress by regulating the physiological and metabolic processes of rice plants, thereby enhancing the stress resistance of the plants, increasing total rice yield in salt stress conditions.

Effects and mechanisms of proanthocyanidins-derived carbon dots on alleviating salt stress in rice by muti-omics analysis

“…The soluble protein content of rice seedling under salt stress was significantly higher in the CDs-treated group compared to the S group, indicating that CDs treatments promoted rice seedlings to produce more soluble proteins and maintain osmotic pressure. The results were consistent with previous study ( Huang et al, 2023 ).…”

Application of prohexadione-calcium priming affects Brassica napus L. seedlings by regulating morph-physiological characteristics under salt stress

“…Plant growth regulators are largely used in controlling plant growth and development ( Desta & Amare, 2021 ). Prohexadione-calcium (Pro-Ca) is a class of environmentally-friendly plant growth regulators that increase crop yield quality ( Chang, 2016 ) and improve plant tolerance to salt stress ( Huang et al, 2023 ). Pro-Ca may control wilt by thickening the cell walls of the thin-walled tissues of the cortex ( Wallis & Cox, 2020 ).…”

Metabolic Adaptations in Rapeseed: Hemin-Induced Resilience to NaCl Stress by Enhancing Growth, Photosynthesis, and Cellular Defense Ability

“…To a certain extent, applying plant growth regulators might overcome adverse environmental factors, improve crop stress resistance, enhance photosynthetic efficiency, and achieve a high level of grain production with better quality. For example, previous studies showed that prohexadione calcium enhanced the net photosynthetic rate of rice under salt stress and increased the activity of antioxidant enzymes, thus promoting plant growth [ 16 ].…”