Unveiling lentil responses to salt stress and gibberellic acid: phenotypic, bioactive and enzymatic dynamics.

Exposing seeds to agents that elicit tolerance to abiotic stress, such as phytohormones and organic acids, during hydration and dehydration cycles can determine their response to later stimuli, e.g. exposure to salt stress. The aim of this study was to evaluate the action of priming cycles with different eliciting agents of salt stress tolerance on seeds of the cowpea varieties Sempre Verde and Pingo de Ouro. The seeds were subjected to the following treatments: 0.0 mM NaCl (control); 100 mM NaCl (salt stress); salt stress + three seed-priming cycles (PC) in water; salt stress + PC in gibberellic acid; salt stress + PC in hydrogen peroxide; salt stress + PC in salicylic acid; salt stress + PC in ascorbic acid. The following variables were analysed: germination, growth, dry weight, salt tolerance index, total soluble sugars, total free amino acids and proline. Salt stress (100 mM NaCl) reduced germination, length and biomass accumulation in the Sempre Verde and Pingo de Ouro varieties. These showed the best response to the priming cycles with gibberellic and salicylic acids, which promoted greater germination potential, length and biomass under a salt stress of 100 mM NaCl, affording greater tolerance via osmotic regulation, especially in the Sempre Verde variety.

Morpho-physiological and molecular responses of two Libyan bread wheat cultivars to plant growth regulators under salt stress

Soil salinity is one of the most significant abiotic stresses limiting plant growth. The ability of plant cells to adapt and survive under salt stress conditions involves triggering a network of signaling events including hormones such as abscisic acid (ABA) known to regulate many important aspects of growth and development. ABA is also known to play a critical role in stress responses such as the regulation of seed germination under salt and osmotic stress. Components of the gibberellic acid (GA) signaling pathway have also been shown to regulate germination; however, the involvement of GA signaling in salt and osmotic stress is largely unexamined. Here, we examined the responses of mutants in the GA signaling pathway (rgl2 and spy) and in the ABA signaling pathway (abi3 and abi5) to salt (NaCl) and osmotic (mannitol) stress during seed germination and early seedling development. Several mutants show resistance to increased levels of both salt and osmotic stress at germination and later stages of seedling development suggesting a role for ABA and GA signaling in these processes. qRT-PCR was employed to determine the effect of salt stress on seed germination via transcriptional control of the components in GA or ABA signaling pathways. We found that RGL2, ABI3, and ABI5 transcripts are greatly induced by NaCl in wildtype plants, but show little if any induction by NaCl in mutant backgrounds suggesting that this regulation of induction during salt stress may occur through ABA–GA crosstalk. Overall, our results indicate that each of the ABA and GA signaling pathways is individually involved in regulation of various seedling developmental stages under stress conditions. In addition, these two hormone pathways appear to be interacting in the regulation of germination and early seedling growth under salt and osmotic stress conditions.

Osmotic stress- and salt stress-inhibition and gibberellin-mitigation of leaf elongation associated with up-regulation of genes controlling cell expansion

An experiment was conducted to study the impact of seed soaking with plant growth regulators (gibberellic acid, indole acetic acid, kinetin, salicylic acid and ascorbic acid) and nutrients (potassium chloride and calcium chloride) on mung bean (Vigna radiata L.) variety Co (Gg) 8 under salt stress condition. The seed and seedling growth under normal and saline (150 mM NaCl) conditions were studied to determine their usefulness in increasing relative salt tolerance by using PGRs and nutrients. Under salt stress, seedling characters were significantly affected compared to normal condition. Seed treatments with gibberellic acid (1mM), salicylic acid (2 mM), ascorbic acid (50 ppm) and kinetin (50 ppm) drastically increased the morphological and biochemical parameters of seedling under saline conditions. All pre-soaking seed treatments increased the germination percentage, shoot and root length, vigour index and stress tolerance index over control. Among the treatments, gibberellic acid, salicylic acid and ascorbic acid showed their supremacy compared to other treatments. Na+ / K+ ratio was decreased by gibberellic acid, CaCl2 (0.5%) and KCl (1%) treatments. It is concluded that treatments with hormones and nutrients have reduced the severity of the salinity effect and the amelioration was observed in all the treatments compare to control. Gibberellic acid and salicylic acid and ascorbic acid showed best results on seedling growth and biochemical characters whereas seed soaking with gibberellic acid, CaCl2 (0.5%) and KCl (1%) were showed its effect on decreased Na+ / K+ ratio under present experimental material and saline conditions.Keywords: Catalase, Mung bean, Na+/K+, Nutrients, PGRs, Salinity, STI, Vigour Index.

The present research study was conducted at the Department of Botany, University of Sargodha, Pakistan to evaluate the performance of two maize varieties under various salinity levels and mitigate the drastic impacts of salinity under the influence of combined and single foliar applications of ascorbic acid and gibberellic acid. Ten seeds of each variety were placed in a pot of each replicate of every treatment. Seeds of two maize varieties were collected from the research institute “Maize and Millet Institute Yousafwala, Sahiwal”. Various attributes of maize varieties, including morphology, physiology, biochemical and nutritional properties, at both the vegetative and reproductive growth stages were evaluated under salt stress and with applications of growth promoters, i.e., ascorbic acid and gibberellic acid. The Sahiwal-2002 performed better than the Akbar in terms of all the parameters under consideration. These findings confirmed that the Sahiwal-2002 has greater salt tolerance potential than Akbar does. Salinity stress drastically reduced the growth and yield of both maize varieties by decreasing their physiological performance and biochemical contents. Therefore, various applications of ascorbic acid and gibberellic acid have been applied as foliar sprays to mitigate the negative effects of salinity on maize varieties at the vegetative and reproductive growth stages. Among all the treatments, at the vegetative stage, foliar application of a combination of ascorbic acid and gibberellic acid (120 ppm and 110 ppm) ameliorated the negative effects of salinity stress on maize crops and can be used to increase the vegetative growth and plant density of maize varieties with improved and stabilized nutritional contents. The sodium level increased with increasing salinity. At the reproductive stage, foliar application of a combination of ascorbic acid and gibberellic acid (240 ppm and 220 ppm) ameliorates the negative effects of salinity stress on maize crops and can be used to increase the growth and yield of maize varieties with improved and stabilized nutritional contents.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-22174-0.

Gibberellic acid (GA) and jasmonic acid (JA) are considered to be endogenous regulators that play a vital role in regulating plant responses to stress conditions. This study investigated the ameliorative role of GA, JA, and the GA + JA mixture in mitigating the detrimental effect of salinity on the summer squash plant. In order to explore the physiological mechanisms of salt stress alleviation carried out by exogenous GA and JA, seed priming with 1.5 mM GA, 0.005 mM JA, and their mixture was performed; then the germinated summer squash seedlings were exposed to 50 mM NaCl. The results showed that a 50 mM NaCl treatment significantly reduced shoot and root fresh and dry weight, water content (%), the concentration of carotenoid (Car), nucleic acids, K+, and Mg++, the K+/Na+ ratio, and the activity of catalase (CAT) and ascorbate peroxidase (APX), while it increased the concentration of proline, thiobarbituric acid reactive substances (TBARS), Na+, and Cl− in summer squash plants, when compared with the control. However, seed priming with GA, JA and the GA + JA mixture significantly improved summer squash salt tolerance by reducing the concentration of Na+ and Cl−, TBARS, and the Chl a/b ratio and by increasing the activity of superoxide dismutase, CAT, and APX, the quantities of K+ and Mg++, the K+/Na+ ratio, and the quantities of RNA, DNA, chlorophyll b, and Car, which, in turn, ameliorated the growth of salinized plants. These findings suggest that GA and JA are able to efficiently defend summer squash plants from salinity destruction by adjusting nutrient uptake and increasing the activity of antioxidant enzymes in order to decrease reactive oxygen species accumulation due to salinity stress; these findings offer a practical intervention for summer squash cultivation in salt-affected soils. Synergistic effects of the GA and JA combination were not clearly observed, and JA alleviated most of the studied traits associated with salinity stress induced in summer squash more efficiently than GA or the GA + JA mixture.

Salt stress is one of the most serious factors limiting the productivity of rice, the staple diet in many countries. Gibberellic acid has been reported to reduce NaCl-induced growth inhibition in some plants including rice. Most paddy soils have a natural population of Cyanobacteria, prokaryotic photosynthethic microorganisms, which synthesize and liberate plant growth regulators such as gibberellins that could exert a natural beneficial effect on salt stressed rice plants. The aim of this work was to evaluate the effect of the cyanobacterium Scytonema hofmanni extracellular products on the growth of rice seedlings inhibited by NaCl and to compare it with the effect of the gibberellic acid in the same stress condition. Growth (length and weight of the seedlings) and biochemical parameters (5-aminolevulinate dehydratase activity, total free porphyrin and pigments content) were evaluated.Salt exposure negatively affected all parameters measured, with the exception of chlorophyll. Chlrorophyll concentrations nearly doubled upon exposure to high salt. Gibberellic acid counteracted the effect of salt on the length and dry weight of the shoot, and on carotenoid and chlorophyll b contents. Extracellular products nullified the salt effect on shoot dry weight and carotenoid content; partially counteracted the effect on shoot length (from 54% to 38% decrease), root dry weight (from 59% to 41% decrease) and total free porphyrin (from 31 to 13% decrease); reduced by 35% the salt increase of chlorophyll a; had no effect on root length and chlorophyll b. Gibberellic acid and extracellular products increased 5-aminolevulinate dehydratase activity over the control without salt. When coincident with high salinity, exposure to either EP or GA3, resulted in a reversal of shoot-related responses to salt stress. We propose that Scytonema hofmanni extracellular products may counteract altered hormone homeostasis of rice seedlings under salt stress by producing gibberellin-like plant growth regulators.

A study was conducted to investigate the effect of presoaking of sugar beet (Beta vulgaris L.) seeds (polygerm) with gibberellic acid, abscisic acid, or ascorbic acid on alleviation of salt stress at seedling stage. The salinity levels of irrigation solution were 0, 25, 50 and 100 mM NaCl and the presoaking treatments were water as a control, 10 µM GA3, 10 µM ABA, and 0.5 mM ASA for 12 hrs. Seeds were sown in plastic pot containing 0.8 Kg prewashed sand and irrigated three times weekly by 100 mL per pot of one-tenth modified Hoagland solution containing the salt level. After seven weeks from sowing, the whole plants were collected. The results indicated that increasing salt concentration decreased the fresh and dry weight of whole plant, shoot and root, and shoot height of all presoaking treatments. However, shoot/root ratio on fresh and dry weight basis and moisture content of whole plant, shoot and root, chlorophyll content index, and electrolyte leakage were increased with increasing salt concentration of all presoaking treatments. However, presoaking of sugar beet seeds (polygerm) with the GA3, ABA, or ASA showed no significant effect to alleviation salt stress on sugar beet seedlings. However, the interaction between salt levels and presoaking treatments was significant for whole plant and root fresh and dry weights, shoot/root ratio on fresh weight basis, whole plant and root moisture content and chlorophyll content index, while nonsignificant for shoot fresh and dry weights, shoot height, shoot/root ratio on dry weight basis, shoot moisture content and electrolyte leakage.

Pretreatment of seeds results in faster emergence of seedlings and uniform stand, especially under stress. Thus, the objective was to evaluate the action of plant regulators as stress attenuators during germination and initial development of pumpkin seedlings, cv. ‘Baiana Tropical’, irrigated with saline water. For this, a completely randomized design was established, in a 4 x 3 factorial scheme, with four replications. Treatments consisted of four types of water (W 1 - 100% supply water; W 2 - 100% fish farming effluent; W 3 - 100% artesian well water; W 4 - mixture of 50% fish farming effluent + 50% artesian well water) and three seed treatments (control, salicylic acid and gibberellic acid). The variables measured were germination, first germination count, shoot and root length, shoot and root dry mass, total soluble sugars, total amino acids and proline. The data were subjected to analysis of variance and Scott-Knott test. Pumpkin seedlings performed osmotic adjustment under saline conditions of W 4 water. In addition, the treatment of pumpkin seeds with plant regulators (gibberellic and salicylic acids) favors the germination and initial development of seedlings under conditions of salt stress.

Abiotic stress prevents plants from absorbing available nutrients resulting in yield loss and soil contamination. Growth regulators like gibberellic acid (GA) may improve plant growth under stress conditions. This study was conducted to evaluate the role of GA on the rice performance under saline conditions and to investigate its effects on regulatory gene expression by GA-mediated seed priming. Seeds of rice variety KSK 282 were primed in GA solution (0, 50, 100 and 150 ppm) and grown under different salt (NaCl) concentrations (0, 50, 100 and 150 mM). Increase in salt concentration led to decrease in rice growth. GA priming reversed the negative effects of salt stress and enhanced different growth attributes like germination, seedling growth and weight, while decreased the concentration of toxic ions such as Na in some treatments. However, GA priming was not very effective on Chlorophyll a, b (Chl-a, Chl-b) and total carotene contents. Reverse transcription polymerase chain reaction (RT-PCR) approach was used to study the effect of GA-mediated seed priming on the expression of two stress responsive genes, OsZat 12-1 (LOC_Os01g62130 also called ZOS1-14 C2H2 zinc finger protein) and OsZat 12-9 (LOC_Os01g62190 also called ZOS1-15 C2H2 zinc finger protein). There was no or very low expression of OsZat 12-1 and OsZat 12-9 in hydroprimed seeds under all salt stress conditions tested, while induction of gene expression was observed for plants raised from GA primed seeds under salt stress. In conclusion, GA regulated the growth at early stages of rice life cycle by inducing regulatory genes expression; therefore it is noteworthy that while studying salinity factor, the induction of genetic determinants (genes) by plant growth regulators should also be considered. © 2016 Friends Science Publishers

When rice (Oryza sativa L. var GR-3) plants were subjected to salt stress (12 dS/m) the extension growth and dry weight of the shoot system as well as the content of chlorophyll and gibberellin-like substances were found to be markedly reduced. Contrarily, the level of abscisic acid in the shoot system registered a rapid and massive increase in response to salinity. Compared to control, salt stressed plants showed higher concentration of Na+ and Cl− and lower concentration of K+ in the leaf tissue. Salinization also resulted in a considerable reduction in grain yield. Exogenous application of gibberellic acid (10 ppm) significantly increased the growth and yield of salt stressed plants. Gibberellic acid treatment reduced the net accumulation of Na+ and Cl− and maintained high level of K+ in the leaves of salinized plants. A significant fall in the content of abscisic acid and a marked increase in the amount of chlorophyll were also noticed in salinized plants in response to gibberellic acid administration. These results suggest that gibberellic acid improved the growth and yield of stressed rice plants presumably by hormonising the ionic status of the plants as well as by modulating the endogenous level of abscisic acid.

Seed germination is the initial step of plant development. Seed priming with salt enhances seed germination in tomato (Solanum lycopersicum L.); however, the molecular and physiological mechanisms underlying the enhancement of seed germination by priming remain to be elucidated. Tomato seeds were soaked for 24 hrs at 25 ºC in the dark in different concentrations of NaCl (NaCl-priming) or distilled water (hydro-priming) and different concentrations of gibberellin. In this study, we examined the expression of genes encoding gibberellic acid (GA) biosynthesis enzymes, including GA 20-oxidase (GA20ox), GA 3-oxidase (GA3ox) and GA4 (GA 3beta-hydroxylase). The germination percentage and germination rate of tomato seeds were increased after soaking with GA under NaCl stress.The expression profiles of GA biosynthesis genes were investigated with the semi-quantitative RT-PCR.Additionally, the expression levels of GA biosynthetic gene were higher in the NaCl-primed seeds than in the hydro-primed seeds. These results suggest that the observed effect of NaCl-priming on tomato seed germination is caused by an increase ofthe GA content via GA biosynthetic gene activation that helps tomato plant to tolerate salt stress.

Hormonal priming has recently emerged as a powerful strategy to increase seed germination and early seedling growth, especially in challenging abiotic stress environments. This study explored the impact of gibberellic acid (GA) and salicylic acid (SA) priming on the germination performance of Stevia rebaudiana seeds under saline conditions. Stevia seeds were either hydroprimed with distilled water (control) or primed with varying concentrations of GA (0.1 and 0.2%) and SA (0.25 and 0.5 mM) and then exposed to salt stress (0 and 80 mM NaCl). The results demonstrated that GA and SA priming significantly enhanced germination rates, reduced mean germination time, and improved the salt tolerance index compared to untreated seeds. Primed seeds showed notable improvements in seedling vigor, including greater shoot and root lengths under salinity stress. The best results were achieved with 0.1% GA and 0.5 mM SA, effectively alleviating the detrimental impact of high salinity on germination. The primed seeds also exhibited reduced electrolyte leakage, signifying improved membrane stability under salt stress. In conclusion, this study presents robust evidence that GA and SA priming is an effective approach for enhancing the germination, salt tolerance index, and early growth of Stevia under saline conditions, offering a practical solution to improve crop establishment in salinity-affected regions.

Plant hormones play an important role in plant adaptation to abiotic stress, but hormonal responses of cool-season turfgrass species to salt stress are not well documented. This study was carried out to investigate the responses of hormones to salt stress and examine if salt stress-induced injury was associated with hormonal alteration in kentucky bluegrass (KBG, Poa pratensis L.). The grass was grown in a growth chamber for 6 weeks and then subjected to salt stress (170 m m NaCl) for 28 days. Salt stress caused cell membrane damage, resulting in photosynthetic rate (Pn), chlorophyll (Chl), and turf quality decline in KBG. Salt stress increased leaf abscisic acid (ABA) and ABA/cytokinin (CK) ratio; reduced trans -zeatin riboside (ZR), isopentenyl adenosine (iPA), and indole-3-acetic acid (IAA), but did not affect gibberellin A4 (GA4). On average, salt stress reduced ZR by 67.4% and IAA by 58.6%, whereas it increased ABA by 398.5%. At the end of the experiment (day 28), turf quality, Pn, and stomatal conductance ( g s ) were negatively correlated with ABA and ABA/CK ratio, but positively correlated with ZR, iPA, and IAA. Electrolyte leakage (EL) was positively correlated with ABA and ABA/CK and negatively correlated with ZR, iPA, IAA, and GA4. GA4 was also positively correlated with turf quality and g s . The results of this study suggest that salt stress-induced injury of the cell membrane and photosynthetic function may be associated with hormonal alteration and imbalance in KBG.