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Arsenic (As) threatens plant growth and human health because its harmful effects are intensified by its persistent presence in the ecosystem. The absorption of As from the contaminated soil leads to accumulation in grains of food crops posing a serious threat to human health. High concentration of As hindered essential physio-biochemical processes of plants that ultimately diminish the growth and yield of crops. Therefore; a pot study was designed to assess synergistic effect of silicon (Si) and salicylic acid (SA) (control-Ck, 4.0 mM Si, 150 µM SA, 4.0 mM Si + 150 µM SA) in mitigating the adversities of As stress in wheat seedlings exposed to As stress (0, and 100 μM). Wheat seedlings exposed to As showed a significant decline in morphological attributes as well as photosynthetic pigments (chlorophyll a, b and carotenoids). However; foliar application of Si and SA considerably increased morphological parameters and leaf photosynthetic pigments under As stress. The imposition of As resulted in enhance accumulation of hydrogen peroxide, MDA, and electrolyte leakage, increased activities of enzymatic antioxidants (superoxide dismutase, peroxidase, and ascorbate peroxidase and catalase) and an elevated accumulation of essential organic osmolytes (free proline, soluble protein, total soluble sugar, total phenolics) in leaves of wheat seedlings. Furthermore, the application of Si + SA resulted in a remarkable increase in the activities of enzymatic antioxidants and accumulation of organic osmolytes. Simultaneously, it reduced the concentration of hydrogen peroxide, MDA, and electrolyte leakage in As-stress wheat seedlings. Under As-stress, sole and combined application of Si and SA caused a significant reduction in arsenic concentration while enhance Si contents in root and shoot of wheat seedlings. In conclusion, synergistic interaction between Si and SA could alleviate the negative impact of As by enhancing the antioxidant defense system, photosynthetic pigments, facilitating osmotic adjustment, and reducing the lipid peroxidation in maize seedlings. The current findings suggest that the combined exogenous application of Si and SA represent a promising approach for promoting the successful cultivation of wheat in As contaminated soil. [ABSTRACT FROM AUTHOR]

Phytotoxic effects of herbicides have been reported on non-target plant species. This study was performed to investigate the growth of Napier grass cv. Pak Chong 1 in herbicide atrazine-contaminated soil; the effect of 1-naphthalene acetic acid, 6-benzyladenine and thidiazuron to stimulate the growth of grass grown in atrazine-contaminated soil; and to determine the remaining atrazine in the soil. The experiment was performed in a factorial completely randomized design with 2 × 10 factors. The first factor was atrazine concentration and the second factor was the application of plant growth regulator. The growth of the plants and atrazine remaining in the soil was analyzed at the end of the experiment (after 26 days). The results showed that Napier grass cv. Pak Chong 1 was tolerant to 6.8 mg/kg atrazine contamination in soil. The shoot growth and root growth of grass grown in atrazine-contaminated soil did not significantly differ from that grown in non-contaminated soil. Thidiazuron and 6-benzyladenine at 0.1 mg/l tended to increase the shoot dry weight of the grass grown in both atrazine-contaminated and non-contaminated soil. Additionally, 10 mg/l of thidiazuron and 1-naphthalene acetic acid tended to decrease the shoot growth of grass grown in both contaminated and non-contaminated soil. Moreover, decreases in atrazine were detected in soil planted with Napier grass cv. Pak Chong 1 by about 67.65% within 26 days. [ABSTRACT FROM AUTHOR]

Paclobutrazol, a fungicide of the triazole class, is widely used as an inducer of early flowering and fruiting by inhibiting gibberellin formation. However, biological assays using model organisms to evaluate their cytogenotoxic and mutagenic potential are still scarce. Therefore, this study aimed to investigate the effects of the commercial product Cultar® 250 SC (CP) and the pure substance (PBZ) on the germination and initial seedling development of Lactuca sativa L. (lettuce), in addition to evaluating the effects of CP on the mitotic activity and DNA, as we believe that PBZ has a greater toxic potential than CP on seed germination, and that the latter has cytogenotoxic and mutagenic effects on L. sativa. Lettuce seeds treated with CP and with PBZ in the doses of 0.25, 0.50, 1, 1.5, and 2 g L−1 showed significant reductions in germination rate, as well the CP reduced the root and initial development seedling development. PBZ showed greater inhibition of germination compared to CP. In direct exposure to PBZ, there was not sufficient seedling development for analysis, while in discontinuous treatment, there was inhibition of root growth (except for doses of 0.25 and 0.50 g L−1) and in the development of the aerial part. While no mitodepressive effect was observed in meristematic cells treated with CP, increased frequencies of chromosomal alterations, including condensed nuclei and micronuclei, were evident in both meristematic cells and the F1 region. The Comet assay further demonstrated higher levels of DNA damage at higher paclobutrazol doses, supporting the findings of increased micronucleus frequencies. Consequently, it can be concluded that the CP exhibits greater toxicity towards seed germination compared to lettuce seedlings, and PBZ has a greater toxic potential than CP in relation to these parameters. However, the impact of CP on seedlings was relatively minimal, as evidenced by their limited effects on development, cell proliferation, and DNA, suggesting a slight toxicity of this agent. Therefore, we infer that Cultar® 250 SC should be used with caution. Thus, this study emphasizes the importance of employing joint analyses to better elucidate and correlate the mechanisms of action of potentially toxic substances. Furthermore, it provides a basis for discussing the application of Cultar® 250 SC and seeking more sustainable alternatives in food production. [ABSTRACT FROM AUTHOR]

• This is the first report on the in vitro propagation of Coelogyne mossiae Rolfe: an endangered endemic orchid of Western Ghats, India. • Among the eight media used, MS media was efficient for asymbiotic seed germination with protocorm (stage IV) establishment. • NAA was proficient in establishing multiple shoot buds and root initials from protocorm explants. • Significant changes in the anatomical characters and biochemicals revealed the adaptability of hardened plants. Coelogyne mossiae Rolfe, an unexplored taxon given its red-listed status by IUCN was selected for in vitro propagation studies due to its conservational significance. The mature pods harboring viable seeds were subjected to inoculation on eight different nutrient media, revealing full-strength Murashige and Skoog (MS) media as highly efficient for seed germination (96.65 %) and subsequent stages of seedling development. Protocorm explants are used for micropropagation on MS media supplemented with various plant growth regulators (PGRs). α- Naphthaleneacetic acid (NAA) in the concentration of 0.5 mg/L facilitated optimal shoot induction resulting in an average of 2.39 multiple buds and 2.46 cm shoot length while 1.0 mg/L 6-Benzyl amino purine (BAP) augmented cultures provided 2.32 multiple shoot buds with an average 1.92 cm height. Half macro-MS augmented with 0.5 mg/L BAP promoted pseudobulb elongation (0.73 cm) while 0.5 mg/L NAA supported root formation (8.33 roots with an average length of 1.12 cm). The resultant plants were acclimatized in pots containing coco peat and brick pieces, exhibiting a survival rate of 63.23 %. The anatomical characteristics of the hardened plants provided insight into factors conducive to their adaptability. Also, the 3-month-old hardened plants demonstrated significantly greater total photosynthetic pigment (0.4915±0.00 mg g-1), total carbohydrate content (72.33±1.69 mg SSE/g), and total protein content (40.26±0.53 mg BSAE/g) when compared to in vitro plants. These findings underscore the potential of in vitro propagation techniques in the conservation and sustainable utilization of Coelogyne mossiae. [ABSTRACT FROM AUTHOR]

Zinc (Zn), a micronutrient, is a source of energy for essential oil (EO) biosynthesis. Methyl jasmonate (MeJA) is a plant growth regulator that has favorable effects on EO quality and quantity. The main objective of this study was to evaluate the interaction effect of Zn and MeJA on the phytochemical traits and EO compositions of peppermint cultivated under soilless conditions. Zn omission and the highest Zn concentration (0.1 mgL−1), which are stress conditions for plants, increased phytochemical traits as well as EO content, and 1 mM MeJA was more suitable for increasing these parameters. The major classes of peppermint EO components were oxygenated monoterpenes, sesquiterpene hydrocarbons, and monoterpene hydrocarbons. The major constituents included menthol, menthone, menthofuran, and 1,8-cineole. Elicitation of peppermint with MeJA at different Zn levels modified the EO composition. The highest menthol content (50.1%) was observed in the 1 mM MeJA and 0.025 mgL−1 Zn treatment groups. In conclusion, this study indicated that Zn and MeJA could be appropriate compounds for changing phytochemical compounds, antioxidant activity, and EO composition. [ABSTRACT FROM AUTHOR]

The effect of N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) on fruit splitting of 'Murcott' tangor fruit (Citrus reticulate × Citrus sinensis) was analyzed throughout two successive seasons during 2020 and 2021. 'Murcott' trees were treated with various concentrations of CPPU, 1.0, 5.0, and 10.0 mg·L−1, which significantly reduced the splitting of fruit compared with the control fruit and the gibberellic acid (GA3)-treated fruit (20.0 mg·L−1). The fruit treated with 5.0 mg·L−1 CPPU exhibited higher levels of fruit weight, longitudinal diameter, transverse diameter, peel strength, and peel thickness compared to the control fruit. In addition, the tree sprayed with 5.0 mg·L−1 CPPU had the greatest number of cellular layers and cells at the stylar end calculated in fruit. However, there were no other fruit quality characteristics significantly affected by CPPU and GA3 treatments. [ABSTRACT FROM AUTHOR]

The edible part of citrus fruit is composed of juice vesicles/sacs which develop from the endocarp, the two to three inner cell layers of the white spongy peel termed albedo. Juice sac primordia usually appear 1 week after anthesis. Hormones, especially auxin and gibberellin, play a role in pericarp development during the ovary-to-fruit transition, but their effect on juice vesicle induction has not been studied. Here, hormone profiling in the pericarp and changes in the expression of their corresponding genes in the endocarp and pericarp were compared between two citrus cultivars: Calabria citron, in which juice sacs develop normally, and Yemenite citron, in which juice sac formation does not initiate. Most of the identified hormones, abscisic acid, gibberellin A4, indole-3-acetic acid, isopentenyladenine, jasmonic acid and zeatin riboside, were at higher levels in Yemenite than in Calabria. Overall, changes in abscisic acid levels in the pericarp were very well correlated with changes in the expression of abscisic acid-related genes in the endocarp. However, the application of various hormones, including abscisic acid, to Calabria flowers failed to arrest juice sac initiation. The possible involvement of abscisic acid and other hormones in the process of juice vesicle initiation and pericarp growth is discussed. [ABSTRACT FROM AUTHOR]

This study explored whether and how prohexadione calcium (Pro-Ca) regulated wheat tolerance to drought stress (DS). Findings displayed that DS had significant influence on antioxidant metabolism, water balance and the photosynthesis. DS significantly improved the activity level of enzymatic antioxidants superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX), the contents of non-enzymatic antioxidants ascorbic acid (AsA) and glutathione (GSH), electrolyte leakage (EL), malondialdehyde (MDA), and the contents of osmotic regulatory substances soluble protein (SP), soluble sugars (SS) and proline (Pro), compared with control. Whereas DS significantly reduced transpiration rate (Tr), stomatal conductance (gs) and relative water content (RWC), photosynthetic pigments chlorophyll and carotenoid contents, net photosynthetic rate (Pn), maximum photochemical efficiency of PSII (Fv/Fm), plant height and biomass. Compared to DS, Pro-Ca plus DS significantly promoted the antioxidant metabolism by improving the activity level of SOD, CAT, POD and APX and increasing AsA and GSH contents, which in turn reduced MDA content and EL. In addition, Pro-Ca plus DS significantly maintained water balance by promoting the accumulation of osmolytes SP, SS and Pro, which in turn increased RWC, Tr and gs. Pro-Ca plus DS also significantly promoted photosynthesis by increasing the contents of the above photosynthetic pigments, Pn and Fv/Fm, thereby promoting plant growth. These findings indicated that Pro-Ca was a potential agent to improve wheat tolerance under water deficit. [ABSTRACT FROM AUTHOR]

Fruit color is a key feature of fruit quality, primarily influenced by anthocyanin or carotenoid accumulation or chlorophyll degradation. Adapting the pigment content is crucial to improve the fruit's nutritional and commercial value. Genetic factors along with other environmental components (i.e., light, temperature, nutrition, etc.) regulate fruit coloration. The fruit coloration process is influenced by plant hormones, which also play a vital role in various physiological and biochemical metabolic processes. Additionally, phytohormones play a role in the regulation of a highly conserved transcription factor complex, called MBW (MYB-bHLH-WD40). The MBW complex, which consists of myeloblastosis (MYB), basic helix–loop–helix (bHLH), and WD40 repeat (WDR) proteins, coordinates the expression of downstream structural genes associated with anthocyanin formation. In fruit production, the application of plant hormones may be important for promoting coloration. However, concerns such as improper concentration or application time must be addressed. This article explores the molecular processes underlying pigment formation and how they are influenced by various plant hormones. The ABA, jasmonate, and brassinosteroid increase anthocyanin and carotenoid formation, but ethylene, auxin, cytokinin, and gibberellin have positive as well as negative effects on anthocyanin formation. This article establishes the necessary groundwork for future studies into the molecular mechanisms of plant hormones regulating fruit color, ultimately aiding in their effective and scientific application towards fruit coloration.Key message: In this article, we have discussed the underlying molecular mechanism of hormonal regulation of fruit color in fruit-bearing plant species. The process of regulating fruit color is influenced by plant hormones which have a significant role in the physiological and biochemical metabolic processes and the control of gene expression and MBW complex activity. [ABSTRACT FROM AUTHOR]

In this paper, I elucidated the influence of γ-aminobutyric acid (GABA) on wheat cadmium (Cd) tolerance. Research results manifested that Cd stress increased superoxide dismutase, catalase, peroxidase, ascorbate peroxidase and glutathione peroxidase activities, and ascorbic acid (AsA) and glutathione (GSH) contents. However, Cd stress decreased AsA/ dehydroascorbic acid (DHA) and GSH/oxidised glutathione (GSSG) ratios, and inhibited photosynthetic performance and plant growth. Compared to Cd alone, GABA plus Cd improved wheat Cd tolerance by increasing the activities of above antioxidant enzymes, AsA and GSH contents, and AsA/DHA and GSH/ GSSG ratios. Meanwhile, compared with Cd alone, GABA plus Cd also enhanced the photosynthetic performance by improving chlorophyll (Chl) and carotenoid (Car) contents and Car/Chl ratio, photosynthetic rate, transpiration rate, stomatal conductance, intercellular carbon dioxide concentration, and Chl fluorescence parameters maximum photochemical efficiency of PSII, photochemical quenching, nonphotochemical quenching and quantum efficiency of PSII photochemistry, which further promoted plant height and biomass. Compared to control, GABA alone also improved above indicators. Current results suggested that GABA can be applied as an anti-cadmium agent in wheat production practice. [ABSTRACT FROM AUTHOR]

Spartina alterniflora is recognized as one of the most detrimental invasive species along China's coastlines, highlighting the need for effective and environmentally safe management strategies to preserve intertidal zones. This study assessed the effectiveness of combining plant growth regulators (PRGs) with physical cutting to manage S. alterniflora, using 16S rRNA and 18S rRNA gene sequencing to evaluate the impacts on the plant and associated soil micro-organisms. The results showed that compared to the control (CK), the regeneration numbers for treatments with abscisic acid (ABA), gibberellin (GA), paclobutrazol (PP333), garcinol (GC), and glyphosate (GP) decreased by 29.75%, 23.25%, 15.75%, 94.50%, and 40.50%, respectively. Comparative analysis revealed no statistically significant variation in the inhibitory effects of ABA and GP on the germination of S. alterniflora (p > 0.05). Additionally, applying PRGs and herbicides increased the diversity indices of soil bacteria and fungi. Principal Coordinates Analysis (PCoA) showed that the impact of PRGs on the fungal community was less pronounced than that of herbicides. Significant differences were also noted in the abundance of microbial functional genes related to methanotrophy, hydrocarbon degradation, and denitrification compared to the control (p < 0.05). This study aimed to assess the potential of PRGs in controlling the invasion of S. alterniflora and to elucidate their impacts on soil microbial communities and functional gene expression. [ABSTRACT FROM AUTHOR]

The recalcitrance of wheat to in vitro culture presents a significant hurdle in its genetic transformation process, directly impacting the ability of explants to regenerate. In light of this challenge, our study aimed to identify the wheat genotype exhibiting the highest responsiveness to callusing and regeneration among elite varieties, with the aim of improving regeneration efficiency within resource and time limitations. We utilized seeds from six diverse wheat varieties as explants. These were cultured on MS media supplemented with different concentrations of 2,4-D to induce callus formation. Following this, we tested six hormonal combinations of IAA and Kinetin to evaluate their impact on regeneration potential from the 2,4-D dichlorophenoxyacetic acid 2,4-D-induced callus. Our results indicate that Millat-11 displayed the most notable regeneration efficiency, reaching 41.66%, particularly when cultured on a regeneration medium containing 1.5 mg/L IAA and 2 mg/L Kinetin. Furthermore, Millet-11 also demonstrated the highest frequency of callus induction, reaching 41.66% on medium supplemented with 2.5 mg/L 2,4-D. In contrast, NARC-09 displayed the lowest responsiveness, with a callus induction frequency of 16.66%. Overall, Millet-11 emerged as the most responsive genotype, suggesting its potential utility in wheat improvement programs. The robust tissue culture response observed in Millet-11 for both callus induction and regeneration underscores its suitability for genetic transformation efforts. These results offer valuable insights for plant breeders seeking to develop new wheat varieties with enhanced adaptability to diverse environmental conditions. [ABSTRACT FROM AUTHOR]

Many plant secondary metabolites are active and important in the regulation of plant growth. Certain plant-derived diterpenes are known to promote plant growth, but the pathways by which this promotion occurs are still unknown. Activity screening revealed that the plant-derived diterpene isopimaric acid exhibits growth-promoting activity in rice (Oryza sativa L.) seedlings. Furthermore, 25 μg/mL of isopimaric acid promoted the growth of 15 self-incompatible associated populations from different rice lineages to different extents. Quantitative analyses revealed a significant decrease in the concentration of the defense-related phytohormone abscisic acid (ABA) following treatment with isopimaric acid. Correlation analysis of the phytohormone concentrations with growth characteristics revealed that the length of seedling shoots was significantly negatively correlated with concentrations of 3-indole-butyric acid (IBA). Moreover, the total root weight was not only negatively correlated with ABA concentrations but also negatively correlated with concentrations of isopentenyl adenine (iP). These data suggest that isopimaric acid is able to influence the phytohormone pathway to balance energy allocation between growth and defense in rice seedlings and also alter the correlation between the concentrations of phytohormones and traits such as shoot and root length and weight. We provide a theoretical basis for the development and utilization of isopimaric acid as a plant growth regulator for rice.

Ethrel®, which contains ethylene, is used as a fruit ripening treatment. However, no information is available on its application as an artificial ripening agent for cacao pods. This study aimed to evaluate the effects of varying ethephon concentrations (0, 1000, 2500, and 5000 ppm) on cacao ripening in a completely randomized design with three replications. Unripe cacao pods, containing fully developed embryos, were utilized in this study. Cacao pods treated with 5000 ppm ethephon ripened five days earlier than untreated samples. In 1000 to 2500 ppm ethephon treatments, the day count required for ripening was three days after treatment (DAT). By 7 DAT, 100% of cacao pods treated with 2500 to 5000 ppm ethephon had ripened. The control treatment had the lowest percentage of ripened pods (50%) at 7 DAT. Total soluble solids (TSS) and titratable acidity (TA) of ripened cacao pods at 7 DAT were not altered substantially in response to ethephon concentrations. The highest TSS/TA ratio (29.13) was recorded in cacaos treated with 2500 ppm ethephon. In contrast, untreated cacao pods had the lowest TSS/TA ratio (23.49). Our findings suggest that ethephon can be used as a plant growth regulator (PGR) for cacao growers to accelerate the ripening of cacao pods. [ABSTRACT FROM AUTHOR]

Gibberellin (GA₃) is a growth hormone that is essential in plant physiological processes. At present, gibberellins are employed in commerce to enhance the physical traits and yield of various vegetable, horticultural, ornamental, and medicinal crops. This research aimed to study the effects of gibberellin application on the morphological characteristics and yield of lettuce plants. The study was arranged in a Completely Randomized Design (CRD) with six treatments of gibberellins concentration with a hydroponic system, namely: G0 = control, G1 = 20 ppm, G2 = 40 ppm, G3 = 60 ppm, G4 = 80 ppm, and G5 = 100 ppm, and each treatment consisted of four replications. This research was conducted in May–July 2023 at the Kemuning Greenhouse, Belu Regency, East Nusa Tenggara. GA₃s were sprayed twice at 2 weeks after sowing and 1 week after transplanting. The results showed that the highest GA₃ concentration (100 ppm) had a negative impact on plant morphology and yield, producing the smallest number of leaves, too long stem, pale green leaves, and the lowest fresh weight. Meanwhile, GA₃ concentration of 40 ppm resulted in the highest number of leaves. However, this increase is not directly proportional to the fresh weight of the leaves. GA₃ concentration of 40 ppm resulted in the best and most efficient yield of leaves and fresh weight, making it highly recommended.

Abstract\nNOVELTY STATEMENTPolycyclic aromatic hydrocarbons (PAHs) are phytotoxic, which can limit their phytoremediation. When the ability of plants to phytoremediation PAHs is compromised, the application of plant growth regulators can enhance the growth of the plants. This study aimed to determine the best plant growth regulator (1-naphthalene acetic acid, 6-benzyladenine, or thidiazuron) to enhance the phytoremediation ability of sweet grass (Pennisetum purpureum cv. Mahasarakham) when grown in weather PAH-contaminated soil. In a greenhouse study, 0.01 mg/l thidiazuron resulted in the highest growth of sweet grass when compared to the other tested plant growth regulators (dry shoot weight 24.11 ± 1.28 g and dry root weight 0.70 ± 0.02 g). Sweet grass was grown in soil contaminated with PAH, which demonstrated the toxicity to sweet grass by reducing the total chlorophyll (1.01 µg/g fresh weight) and carotenoid (0.28 µg/g fresh weight) contents with proline increased (6.63 µg/g fresh weight). Meanwhile, total chlorophyll, carotenoid, and proline content in leaves of sweet grass grown in non-contaminated soil were 1.68, 0.44, and 5.23 µg/g fresh weight, respectively. When sweet grass was used to phytoremediate PAHs, there were reductions in acenaphthylene (4.69 ± 0.50%), acenaphthene (10.69 ± 1.47%), and phenanthrene (3.61 ± 0.07%), which compared to levels of over 30% in non-planted soil. For the three PAHs, the bioconcentration factors were 1.6 to 2.4, but the translocation factors were below 1, showing limited movement to the aerial parts of the plant, thereby suggesting that the main mechanism is rhizoremediation. Sweet grass is an excellent candidate for PAH remediation, especially when thidiazuron is applied to relieve plant stress.Thidiazuron at 0.01 mg/l was the best plant growth regulator to stimulate the growth of sweet grass when compared to 1-naphthalene acetic acid and 6-benzyladenine. Sweetgrass enhanced the removal of acenaphthylene, acenaphthene, and phenanthrene from contaminated soil. A possible mechanism for polycyclic aromatic hydrocarbon (PAH) remediation was rhizoremediation, as the accumulation of PAH in sweet grass biomass was limited, and the translocation factor from the root to the shoot was lower than 1. Thidiazuron may indirectly enhance the PAH phytoremediation by sweet grass via increased plant tolerance to PAH toxicity. [ABSTRACT FROM AUTHOR]

The application of Silicon modulates the plant defense mechanism by signaling secondary defense metabolites activating signal transduction pathways further triggering the HIPVs which in turn attracts natural enemies thereby suppressing the pest population. Continuous mono culturing of high yielding varieties with intensive cultural practices lead to depletion of available Si in soils and hence exogenous application of Si sources is necessary. Exploiting plant resistance and strengthening the induced defenses through Si and PGR could represent an effective viable alternative to synthetic insecticides that could form an efficient tactic in integrated pest management including biological control. In this context, we underscore recent advancements in understanding Si-mediated enhancement of plant resistance against pests, emphasizing the significance of these findings for potential incorporation into future strategies for crop protection. [ABSTRACT FROM AUTHOR]

Gibberellin (GA3) is a growth hormone that is essential in plant physiological processes. At present, gibberellins are employed in commerce to enhance the physical traits and yield of various vegetable, horticultural, ornamental, and medicinal crops. This research aimed to study the effects of gibberellin application on the morphological characteristics and yield of lettuce plants. The study was arranged in a Completely Randomized Design (CRD) with six treatments of gibberellins concentration with a hydroponic system, namely: G0 = control, G1 = 20 ppm, G2 = 40 ppm, G3 = 60 ppm, G4 = 80 ppm, and G5 = 100 ppm, and each treatment consisted of four replications. This research was conducted in May-July 2023 at the Kemuning Greenhouse, Belu Regency, East Nusa Tenggara. GA3s were sprayed twice at 2 weeks after sowing and 1 week after transplanting. The results showed that the highest GA3 concentration (100 ppm) had a negative impact on plant morphology and yield, producing the smallest number of leaves, too long stem, pale green leaves, and the lowest fresh weight. Meanwhile, GA3 concentration of 40 ppm resulted in the highest number of leaves. However, this increase is not directly proportional to the fresh weight of the leaves. GA3 concentration of 40 ppm resulted in the best and most efficient yield of leaves and fresh weight, making it highly recommended. [ABSTRACT FROM AUTHOR]

Global warming has led to more frequent extreme weather events, such as heavy summer rains, in the Huang‐Huai‐Hai region. These events significantly impede the growth and development of waxy maize in the area and disrupt the stable progression of the industry. However, there is a lack of effective agricultural measures to mitigate the impact of waterlogging, and the underlying regulation mechanisms remain unclear. To fill this knowledge gap, we conducted a two‐year experiment to assess whether exogenous EDAH (a mixture of ethephon and diethyl aminoethyl hexanoate (DA‐6), ethephon: DA‐6 = 27%: 3%) application during the waxy maize V6 stage, combined with 10 days of waterlogging treatment at the V6, VT and R2 growth stages. The results indicate that exogenous EDAH mitigates the adverse effects of waterlogging stress to a certain extent. It is noteworthy that exogenous EDAH increases the leaf area index and photosynthetic parameters of waxy maize, enhances the activity of catalase in ear leaves at the R3 stage, inhibits the accumulation of malondialdehyde and delays premature aging of plants. Furthermore, exogenous EDAH delays premature ripening of grains caused by waterlogging, increases the moisture content of fresh waxy maize grains during the fresh edible period, but does not effectively mitigate the yield losses caused by waterlogging. However, exogenous EDAH effectively improves grain quality under waterlogging stress, increasing the soluble sugar content and total protein content while reducing starch content, ultimately enhancing the edibility of fresh ears. Through TOPSIS comprehensive evaluation, it can be inferred that exogenous EDAH effectively mitigates the overall impact of waterlogging on waxy maize at both the V6 and VT stages. This research sheds light on potential strategies to mitigate the adverse effects of waterlogging on agricultural productivity and grain quality. [ABSTRACT FROM AUTHOR]

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State The Netherlands for the pesticide active substance 1‐methylcyclopropene are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council for an amendment in approval conditions. The current approval of 1‐methylcyclopropene includes the specific provision 'Only uses as plant growth regulator for post‐harvest storage in sealable warehouse may be authorised'. The applicant AgroFresh Holding France SAS submitted, in accordance with Article 7 of Reg. (EC) 1107/2009, an application to remove this specific provision in order to allow member states to authorise the use of products containing 1‐methylcyclopropene on outdoor crops pre‐harvest. The conclusions were reached on the basis of the evaluation of the representative use(s) of 1‐methylcyclopropene as a plant growth regulator via spray application on pome fruit. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified. [ABSTRACT FROM AUTHOR]

Increasing climatic temperatures and precipitation in the autumn may lead to increased injury and decay during extended storage of mandarin fruits. In this study, we examined the internal fruit quality, rind color, ultrastructure of the peel, inorganic composition of albedo, and flavonoid contents of the flavedo at harvest in the early-maturing cultivar satsuma mandarin 'Miyagawa Wase.' Fruits were treated with a mixture of gibberellic acid (GA; 25 mg L− 1) and prohydrojasmon (PDJ; 100 mg L− 1) denoted as (GP), only GA (25 mg L− 1), and only PDJ (100 mg L− 1) in August and September. Specific gravity and titratable acidity (TA) of the GA-treated fruits were higher than those of the non-GA-treated fruits (PDJ and control), while lower ratios of soluble solids content (SSC) and TA were observed. The GA-treated fruits' L* (lightness), a* (bluish-green/red-purple hue component), b* (yellow-blue hue component), and C* (chroma) values were significantly lower than those of non-GA-treated fruits. In particular, a* value of GP (0.5) was significantly lower than that of control (24.6). The non-GP-treated fruits had higher epicuticular wax on the peel than GP-treated fruits. The distributions of N, P, and Mg in the GA-treated fruits were higher than those in non-GA-treated fruits. Nobiletin and tangeretin contents of the flavedo were the highest in the GP treatment, followed by the GA, PDJ, and control treatments. The occurrence of rind disorder after 20 d of storage was the lowest in GP, whereas PDJ and control treatments showed 18% over. These results indicate that the combined treatment with GA and PDJ has a more substantial effect than treatment with only GA or PDJ in controlling peel ripening at harvest and rind disorder after storage in satsuma mandarin fruits. [ABSTRACT FROM AUTHOR]

Puya chilensis is an endemic species of Chile belonging to the Bromeliaceae family, known for its morphological plasticity and ecological importance. In recent years, greater attention has been given to its conservation due to the indiscriminate use of its populations for food and medicinal purposes. In vitro culture is a tool for the propagation of plants species, as well as for obtaining bioactive compounds. In Chile, P. chilensis is the most representative within the Puya genus. This study focused on establishing an in vitro propagation protocol for P. chilensis that allows massive propagation and obtaining proteolytic enzymes. The combined effect of plants cuts and the application of 0.5 µmol L−1 of BAP and GA3 favored the in vitro multiplication of P. chilensis. Culture in liquid medium induced greater morphological development and early differentiation of anatomical structures in the leaves of P. chilensis in vitro. The use of TIS creates ideal conditions during the last stage of in vitro culture and ensures 100% survival during acclimatization phase. The management of cultivation conditions and the efficient use of TIS allowed the generation of P. chilensis plants with an optimal degree of development for obtaining proteolytic extracts. The main enzymes present in the extracts of P. chilensis plants grown in vitro belong to the cysteine type. This study proposes for the first time an optimized protocol for the propagation and conservation of P. chilensis, enhancing its uses as a source of biologically active molecules for the biotechnology and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Extensive research has been conducted on the in vitro mass propagation of pear (Pyrus spp.) trees through vegetative propagation, demonstrating high efficiency in shoot multiplication across various pear species. However, the low in vitro rooting rates remain a significant barrier to the practical application and commercialization of mass propagation. This study aims to determine the favorable conditions for inducing root formation in the in vitro microshoots of Pyrus genotypes. The base of the microshoots was exposed to a high concentration (2 mg L−1) of auxins (a combination of IBA and NAA) for initial root induction at the moment when callus formation begins. The microshoots were then transferred to an R1 medium (1/2 MS with 30 g L−1 sucrose without PGRs) to promote root development. This method successfully induced rooting in three European pear varieties, one Asian pear variety, and a European–Asian hybrid, resulting in rooting rates of 66.7%, 87.2%, and 100% for the European pear (P. communis), 60% for the Asian pear (P. pyrifolia), and 83.3% for the hybrid pear (P. pyrifolia × P. communis) with an average of 25 days. In contrast, the control group (MS medium) exhibited rooting rates of 0–13.3% after 60 days of culture. These findings will enhance in vitro root induction for various pear varieties and support the mass propagation and acclimatization of pear. The in vitro root induction method developed in this study has the potential for global commercial application in pear cultivation. [ABSTRACT FROM AUTHOR]

The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Finland, and co‐rapporteur Member State, Estonia, for the pesticide active substance mepiquat (evaluated variant mepiquat chloride) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of mepiquat chloride as a plant growth regulator on cereals and grass (field uses). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified. [ABSTRACT FROM AUTHOR]

Indole-3-propionic acid (IPA) is a plant growth regulator with good specificity and long action. IPA may be harmful to human health because of its accumulation in vegetables and fruits. Therefore, in this study, the properties of the interaction between calf thymus DNA (ctDNA) and IPA were systematically explored using multispectroscopic and computational modeling approaches. Analysis of fluorescence spectra showed that IPA binding to ctDNA to spontaneously form a complex was mainly driven by hydrogen bonds and hydrophobic interaction. DNA melting analysis, viscosity analysis, DNA cleavage study, and circular dichroism measurement revealed the groove binding of IPA to ctDNA and showed that the binding did not significantly change ctDNA confirmation. Furthermore, molecular docking found that IPA attached in the A-T rich minor groove region of the DNA. Molecular dynamics simulation showed that DNA and IPA formed a stable complex and IPA caused slight fluctuations for the residues at the binding site. Gel electrophoresis experiments showed that IPA did not significantly disrupt the DNA structure. These findings may provide useful information on the potential toxicological effects and environmental risk assessments of IPA residue in food at the molecular level. [ABSTRACT FROM AUTHOR]

Plant growth regulators have been used in the cultivation of medicinal plants to increase yield, but the existing regulators decreased the content of active constituents which benefit human health. Therefore, it is necessary to find a new growth regulator to achieve the win-win goal of increasing yield and improving active constituents' accumulation. The potential of replacing chlorocholine chloride with a new humic acid-based growth regulator was evaluated by measuring the yield and active constituents' accumulation of Codonopsis pilosula. Three treatments including water (CK), chlorocholine chloride (T1) and humic acid regulator (T2) were applied by foliar spraying. Among them, both chlorocholine chloride and humic acid regulator belong to biostimulant. The result showed that the root yield in T1 and T2 were significantly increased by 59.1% and 54.9% compared with CK, respectively, and there was no significant difference between T1 and T2. Compared with CK, the yields of lobetyolin, syringin and atractylenolide III of Codonopsis pilosula were significantly decreased by 6.3%, 7.3% and 13.0% in T1, but were significantly increased by 22.8%, 14.8% and 32.0% in T2, respectively. Redundancy analyses showed that photosynthetic rate, sucrose phosphoric acid synthetase and phosphomannomutase had higher degree of explanation for yield and quality. Linear regression results indicated that photosynthetic rate and phosphomannomutase were the main factors to affect yield and active constituents yields, respectively. In addition, the output-input ratios based on the yields of polysaccharides, lobetyolin, syringin and atractylenolide III of Codonopsis pilosula in T2 was significantly increased by 6.5%, 15.2%, 8.7% and 31.2% respectively as compared with T1. Overall, compared with water treatment, both chlorocholine chloride and humic acid regulator treatments can increase the root yield of Codonopsis pilosula. Compared with chlorocholine chloride, humic acid regulator can improve the yield of active constituents and economic benefits of Codonopsis pilosula. This study indicated that reasonable selection of plant growth regulators is of great significance for achieving a win-win goal of increasing the root yield and active constituents of medicinal plants. [ABSTRACT FROM AUTHOR]

Shaping the canopy architecture and delaying leaf senescence in maize are pivotal strategies for extending the crop's photosynthetic period and improving yield. The application of plant growth regulators (PGRs) is a critical cultivation measure, with the timing of application being of paramount importance. To explore the effects of PGR application time on maize canopy structure, leaf senescence characteristics and yield, a comparative two-year field study was undertaken during the 2019–2020 growing seasons at the Gongzhuling Experimental Station of the Jilin Academy of Agricultural Sciences, utilizing a PGR containing ethephon as the active ingredient. The experiment was structured with two plant densities of 60,000 and 90,000 plants ha−1, and three distinct PGR application protocols: T10 (application of PGR at the 10th leaf stage), T15 (application at the 15th leaf stage), and CK (control group sprayed with water). The result indicated that the yield increased by 5.62% following T15 treatment compared to the CK under high density (90,000 plants ha−1). Furthermore, the kernel per ear and the 1000-kernel weight increased by 3.93% and 5.62% respectively, while the abortion rate decreased. Correlation analysis showed that yield and yield components were correlated with plant morphology, physiology, and aging characteristics under 90,000 plants ha−1. Pollen density was also positively correlated with the top leaf area and the top leaf angle (p < 0.01). Furthermore, relative green leaf area at maturity (RGLAM) showed positive correlations with chlorophyll b, superoxide dismutase activity (SOD), peroxidase activity (POD), catalase activity (CAT), and soluble protein content (p < 0.01), while displaying a negative correlation with malondialdehyde content (MDA) (p < 0.01). Spraying plant growth regulators at the 15-leaf stage under high density can effectively enhance the top canopy structure of the maize and reduce the upper leaf area and angle, increase pollen density, and boost the number of grains. Furthermore, it delayed the senescence of leaves, prolonged the functional period of the leaves, increased kernel weight, optimized light resource utilization, and ultimately enhanced the maize yield. [ABSTRACT FROM AUTHOR]

Gibberellic acid (GA3) is a tetracyclic diterpenoid carboxylic acid synthesized by the secondary metabolism of Fusarium fujikuroi. This phytohormone is widely studied due to the advantages it offers as a plant growth regulator, such as growth stimulation, senescence delay, flowering induction, increased fruit size, and defense against abiotic or biotic stress, which improve the quality and yield of crops. Therefore, GA3 has been considered as an innovative strategy to improve agricultural production. However, the yields obtained at large scale are insufficient for the current market demand. This low productivity is attributed to the lack of adequate parameters to optimize the fermentation process, as well as the complexity of its regulation. Therefore, this article describes the latest advances for potentializing the GA3 production process, including an analysis of its origins from crops, the benefits of its application, the related biosynthetic metabolism, the maximum yields achieved from production processes, and their association with genetic engineering techniques for GA3 producers. This work provides a new perspective on the critical points of the production process, in order to overcome the limits surrounding this modern line of bioengineering. [ABSTRACT FROM AUTHOR]

Inadequate lateral branch development can lead to decreased apple (Malus ×domestica Borkh.) orchard productivity and profitability in modern high-density orchard systems. Although plant growth regulator applications are used to increase lateral branching on leaders of young apple trees, inconsistent responses have been observed in the southeastern United States. In North Carolina and Washington, three experiments were conducted to identify effective leader management strategies to increase lateral branching. Effects and interactions of leader bagging, 6-benzyladenine (6-BA), and 6-BA + gibberellic acid (GA4+7) on lateral branch development of 1-year-old leaders were evaluated. Across all experiments, leader bagging was an influential factor. When compared with unbagged trees, leader bagging increased lateral branch number (20% to 48%), number of feathers (74% to 125%), average branch length (28% to 34%), and total linear bearing surface (428%) of the treated section of the leader. Blossom cluster density and final fruit set were increased in bagged trees, 65% and 36%, respectively. At the rates and timings tested, 6-BA and 6-BA + GA4+7 were generally ineffective in stimulating lateral branching and interactions among the factors evaluated were not influential. Leader bagging was an effective lateral branch induction strategy, although the mechanism of action is poorly understood. Future research to characterize the bagged environment and/or physiological responses to bagging may aid in the development of future environmentally sustainable technologies to stimulate lateral branching of apple trees. [ABSTRACT FROM AUTHOR]

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Objective: The present study was performed to study the effects of MS, WPM, B5 culture media and benzylaminopurine (BAP) hormone on hyssop proliferation, and to assess the effects of different concentrations of IBA and IAA hormones on rooting characteristics of hyssop. Methods: The experiments were conducted as a factorial with a completely randomized design with three replications at the laboratory of tissue culture of the Faculty of Agriculture, University of Jiroft. To produce sterile seedlings, seeds were collected from mountainous regions of Kerman province and planted on the MS medium. The single-node explants were cultivated on MS, WPM, and B5 culture media containing the benzylaminopurine hormone with concentrations of 0, 1, and 2 mg/L. To induce rooting, the shoots were placed on the MS culture medium containing 0.5 and 1 mg/L of indole butyric acid and indole acetic acid. GiaRoots software was employed to analyze the architecture of the roots obtained. Results: Based on the research results, the highest proliferation coefficient was obtained in the MS culture medium with a concentration of 2 mg/L of benzylaminopurine hormone. In addition, the results of root architecture analysis showed that IBA hormone with a concentration of 1 mg/L demonstrated the most effective treatment for rooting induction. Conclusion: The adaptation test results demonstrated that 85% of the plants transferred to the greenhouse survived. [ABSTRACT FROM AUTHOR]

Vegetative growth of Cattleya orchids is influenced by environmental factors. In addition, growth and development are also determined by the availability of nutrients and hormones. One of the methods to accelerate the vegetative growth of orchids is by the application of NPK fertilizers and plant growth regulators such as benzyl amino purine (BAP). The objective of this study was to obtain the best concentration of NPK and BAP concentration on the vegetative growth of Cattleya orchids. The experiment was conducted at the screenhouse of the Experimental Garden of Bale Tatanen, Faculty of Agriculture, Padjadjaran University with a Factorial Randomized Block Design consisting of two factors, namely the concentration of NPK fertilizer (0, 1, 2, 3, and 4 g L-1 of NPK-28:10:10 and 2 g L-1 of NPK-32:10:10 as positive control), and the second factor was BAP concentration (0, 0.5 and 1 mg L-1) with three replications. The results showed that there was an interaction effect between the application of 2 g L-1 of NPK 28:10:10 and 1 mg L-1 BAP on the number of pseudobulbs per clump. Independently, the treatment of 2 g L-1 of NPK 28:10:10 showed the best results in the increase of plant height and the number of new shoots. While 0.5 mg L-1 of BAP showed the best results in the increase of plant height, the number of new shoots and the SPAD value.

The heavy metal cadmium (Cd) is a major threat to food safety and human health. Phytoremediation is the most widely used remediation technology, and how to improve the remediation efficiency of phytoremediation has become a key issue. In this study, we constructed an intensive phytoremediation technology for remediation of Cd-contaminated soil with biodegradable chelating agent and plant growth regulator combined with maize and investigated the mechanism of this technology. The results showed that the best remediation effect was achieved in the treatment with 10−6 mol l−1 gibberellic acid (GA3) and 6 mmol kg−1 aspartate diethoxysuccinic acid (AES) combined with maize. In this treatment, the total biomass and extraction efficiency of maize were 3.6 and 8.67 times higher than those of the control, respectively, and the antioxidant enzyme activities of maize were also increased. The soil was enriched with dominant bacterial genera that promote plant growth and metabolism and tolerance to heavy metal stress, which in turn promoted maize growth and Cd accumulation. Structural equation modelling results indicated a large effect of plant Cd concentration and plant antioxidant enzyme activity on plant Cd extraction. The enhanced phytoremediation technology showed good potential for safe use of Cd-contaminated soil.

The application of plant growth regulators, primarily gibberellin inhibitors, is the main approach used for controlling the growth of ornamental plants. However, there is a growing interest in alternative products due to the risk of environmental toxicity associated with traditional methods. Methyl jasmonate (MeJa) is a natural substance found in plants and is considered to have low toxicity when used appropriately. Its use as a growth regulator has shown promise for controlling plant growth, but its effects have not been extensively explored in ornamental growth restriction. This study investigated the effects of foliar application of different concentrations of MeJa (0, 50, 100, and 150 µM) on the growth and leaf anatomy of Begonia ‘Dragon Wing’ Pink and Red. Plant growth parameters were evaluated, and qualitative-quantitative histological analyses of Begonia leaves were conducted. MeJa was efficient in compacting the plants, reducing height in 17.57% and diameter in 8.98% without compromising biomass, root growth, and flowering aspects. The average concentration studied also caused changes in leaf anatomy, increasing the thickness of the abaxial epidermis, reducing mesophyll thickness, the number of calcium oxalate crystals, and the size and number of stomata. The results demonstrated the promising effect of MeJa on controlling the growth of potted ornamental plants.

Cold-hardy hybrid grape cultivars have low tannin content compared to Vitis vinifera cultivars, which leads to unbalanced red wines and therefore low-quality wines. Viticultural practices, such as nitrogen fertilisation and the use of plant growth regulators, have shown to be effective interventions to modify tannin content in V. vinifera cultivars and may be effective with cold-hardy hybrids. Foliar applications of phenylalanine (Phe, 100 mg/L) and prohexadione calcium (ProCa, 50 mg/L) were applied separately and in combination (ProCa+Phe) to Marquette grapevines grown in Iowa, USA in 2022 and 2023. Treatments were assigned following a split-plot design. Berry weight, diameter, seeds per berry, tannin content, and iron-reactive phenolics content of skins and seeds were analysed at five phenological time points. Samples from treated vines were compared to untreated control samples using a random-intercepts linear regression model. Overall, the effect of year was more impactful than the individual effects of treatments due to differences in temperature and rainfall during berry development. However, skin and seed tannin and IRP were significantly affected by the Year2023:ProCa interaction at 3 weeks post fruit set and véraison, respectively, suggesting ProCa treatment may be more effective with multiple applications in consecutive years. Low application rate may be a reason for limited treatment effectiveness and further work on dose response may demonstrate foliar sprays of Phe and ProCa to be effective tools at managing phenolics content in Marquette grapes.

Relevance. The purpose of the research was to improve the elements of zonal agricultural technology for cultivating a new variety of sweet pepper Zarnitsa, to study the possibility of increasing productivity, reducing production costs during its seed production through the use of a non-seedling method of cultivation in irrigated conditions and the plant growth regulator Zircon, R.Methodology. Experimental studies were carried out on the experimental field of All-Russian Research Institute of Irrigated Vegetable and Melon Growing (Astrakhan region) in 2022-2023. The establishment of the field experiment and the carrying out of records and observations in the experiment were carried out in accordance with generally accepted methods.Results. It was found that with the seedless method of growing sweet pepper, the period from sowing to the start of fruit harvesting was 12 days shorter. Sweet pepper plants in the seedling method during the fruiting phase had advantages: in plant height by 9.3%, in the number of lateral shoots by 21.2%, in leaf weight by 7.0%, in average fruit weight by 6.1%. The highest yield, on average 31.6 t/ha, was obtained using the seedling method; when sowing seeds in the ground, it was 3.8% lower. Replacing the seedling method of cultivation with a non-seedling method contributed to a reduction in production costs by 74.7 thousand rub./ha, production costs by 1.9 thousand rub./t, production profitability by 1.2 times, due to savings in labor resources and working capital for growing and planting seedlings. Replacing the seedling method of cultivation with a non-seedling method helped reduce production costs by 74.7 thousand rub./ha, production costs by 1.9 thousand rubles/t, the profitability of production of sweet pepper products and seeds by 1.2 times, due to savings labor resources, working capital for growing, planting seedlings. A single treatment with the plant growth regulator Zircon, P (30 ml/ha) at the beginning of flowering contributed to a significant increase in plant biometric parameters: height by 12.2%, number of lateral shoots by 30.8%, leaf weight by 14.3%, yield by 2.4 t/ha (7.9%), compared to the control (30.4 t/ha), an increase in sugar content by 0.2%, vitamin C by 4 mg% and seed yield by 9 kg/ha (8.7%). The sowing qualities of sweet pepper seeds in all variants of the experiment met the standard requirements and were – 94-95% in terms of germination and – 92-94% in terms of germination energy. The highest level of profitability of 204.9% was obtained as a result of using a growth regulator; in the option without treatment it was lower by 14.4%.

Melon productivity in Indonesia has been declining. Global climate change is affecting the productivity of melons. Long-term droughts have contributed to a reduction in plant growth and development. Hormopriming is an alternative to increase the germination and growth of melon plants by soaking seeds in a solution of plant growth regulators. Brassinosteroid can enhance germination and plant tolerance under drought conditions. The objective of this research is to examine the impact of brassinosteroid hormopriming treatment on the germination and growth of melon plants subjected to various degrees of drought stress. The study utilized a two-factor fully randomized design. The brassinosteroid concentrations used were 0, 0.05, 0.10, and 0.15 ppm. Media with different water capacities of 75%, 50%, and 25% Space Capacity (SC) were used to test drought stress resistance. Water capacities were examined using the gravimetric method. This study's findings suggest that treating melon plants with brassinosteroid variations can induce drought resistance in M15 melons. A brassinosteroid concentration of 0.15 ppm is the best concentration, as it can increase all parameters of plant growth and adaptation under each variation of water availability provided. The findings of this study can serve as a reference for melon cultivators constrained by dry land conditions to increase the efficiency of cultivation.

Scarf skin is a fruit finish disorder of apple that leads to reduced grade quality and rejected crop loads. Although not established as a disorder specific to certain cultivars, the manifestation of the disorder is more apparent on red-skinned cultivars such as Gala and Stayman at harvest, where its whiteish cast is held in clear contrast with the redness of the mature fruit. The disorder afflicts fruit during the first 40 days after petal fall as the fruitlet is developing, although symptoms of the disorder may not be clearly visible until many months after. The exact causes of apple scarf skin are not well defined, although it is known that the presence of the disorder can be influenced by environment, fruit size, and some pesticides. Management currently relies on four applications of the plant hormones gibberellins A4 and A7 (GA4+7) during the first 40 days after bloom. Here, we describe our attempts to use a commercialized GA4+7 product (ProVide 10SG) starting at petal fall, with applications made after or before rainfall events, to ease rainfall's putative influence on scarf skin development. We compared our programs to the standard program over 4 years in research orchards and a commercial orchard but observed no consistent reduction in scarf skin severity or incidence of out-of-grade fruit, in part due to the year-to-year variability in the manifestation of scarf skin. Rainfall, at the thresholds defined, does not appear to be a sufficiently significant factor influencing scarf skin development such that a GA4+7 management program can be designed. [Figure: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

With the aim of evaluating the effects of salicylic acid and brassinosteroid application on some physiological traits and arsenic accumulation in spinach under arsenic stress conditions, an experiment was conducted in a factorial experiment in the form of a randomized complete block design with four replications in the year 2022 in the Nutrition Research Center, Department of Food Hygiene and Quality Control, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Iran. The experimental factors included salicylic acid (0, 0.5, and 0.75 mM), brassinosteroid (0, 0.5, and 0.75 µM), and arsenic stress (0, 50, and 100 µM). Arsenic stress, especially at 100 µM, reduced the net photosynthetic rate, transpiration rate, stomatal conductance of spinach leaves and biomass. Arsenic stress increased the concentration of malondialdehyde, hydrogen peroxide, osmolytes, as well as antioxidant enzymes activities in spinach plants. Application of brassinosteroid and salicylic acid significantly increased activities of antioxidant enzymes (peroxidase, ascorbate peroxidase, and superoxide dismutase), osmolytes accumulation (carbohydrates and proline) and spinach biomass; in contrast, application of brassinosteroid and salicylic acid decreased the concentration of malondialdehyde and hydrogen peroxide in spinach plants under arsenic stress conditions. Arsenic accumulation was higher in spinach roots than in leaves. Under 100 µM arsenic stress, the application of different concentrations of salicylic acid and brassinosteroid, individually and in combination, significantly reduced arsenic accumulation in spinach, with the highest positive effect being observed in the treatment of 0.75 mM salicylic acid + 0.75 µM brassinosteroid. In conclusion, brassinosteroid and salicylic acid application increased the tolerance of spinach plants against arsenic stress by improving gas exchange, activity of antioxidant enzymes, accumulation of osmolytes, stability of the membranes, and as a result plant biomass; the positive effects of brassinosteroid and salicylic acid together were greater than that of brassinosteroid or salicylic acid applied separately.

Abstract The postharvest life of cut flowers is limited, which is a major challenge and varies greatly depending on plant varieties, cut flower stage, flower length of the harvested shoots, and storage conditions including postharvest treatments. As a result, improving the vase life and quality of cut flowers in regulating postharvest characteristics and overcoming these challenges is critical to the horticulture business. Novel engineered nanocomposites were created and tested for possible impacts on flower bud opening, postharvest life extension, longevity regulation, and preservation and enhancement of the strength and appearance of cut flowers. The experiment was conducted as a factorial experiment using a completely randomized design (CRD) with two factors. The first factor was two holding solutions (without or with sucrose at 20 gL−1). The second factor was 12 pulsing treatments for 24 h; distilled water as a control, 75 ppm GA3, multi-walled carbon nanotubes MWCNTs at 10, 20, 30, 40, and 50 ppm, and MWCNTs (10, 20, 30, 40, and 50 ppm)/GA3 (75 ppm) composites; each treatment had 3 replicates, for a total of 72 experimental units. In the present study, gibberellic acid (GA3) was synthesized in functionalized (MWCNT/GA3 composites) as a novel antisenescence agent, and their effect on the vase life quality of cut rose flowers Rosa hybrida cv. ‘Moonstone’ was compared by assaying several parameters critical for vase life. The adsorption of GA3 on MWCNTs was proven by performing FTIR spectroscopy which ensures that the formation of the MWCNTs/GA3 composite preserves the nanostructure and was examined by high-resolution transmission electron microscopy (HR-TEM). The results revealed that sucrose in the holding solution showed a significant increase in fresh weight, flower diameter, and vase life by 10.5, 10.6, and 3.3% respectively. Applying sucrose with MWCNTs 20 ppm/GA3 75 ppm composites or MWCNTs 20 ppm alone, was critical for the significant increase in flower opening by 39.7 and 28.7%, and longevity by 34.4 and 23.2%, respectively, and significantly increased chlorophyll a, b, total chlorophyll, anthocyanin, total phenolic content, and 2,2-Diphenyl-1-picrylhydrazyl scavenging activity as compared to the control.

Optimized maize (Zea mays L.) canopy architecture enhances density-tolerance. DHEAP (N, N-Diethyl-2-hexanoyl oxygen radicals-ethyl amine (2-ethyl chloride) phosphonic acid salt) has been shown to increase maize upper canopy strata compactness, but its overall effect on the whole canopy structure and how it shapes the canopy structure remain unclear. This study examined how DHEAP affected the canopy structure of maize hybrids Zhengdan 958 (ZD958) and Xianyu 335 (XY335), with distinct canopy structures, under different planting densities. The results showed that DHEAP increased the leaf orientation value (LOV) of upper canopy strata by 8.0% while reducing middle and lower strata LOV by 11.7% and 18.4%, respectively. This indicates that DHEAP shaped a canopy structure that was compact in the upper strata and loose in the middle and lower strata. Multiple linear regression analysis showed that leaf angle had a greater impact on the upper canopy strata, while leaf auricle size had a greater impact on the middle and lower canopy strata. After DHEAP treatment, light transmission above different canopy strata increased at the reproductive stage. Concurrently, the middle canopy captured more light energy, enhanced yield formation, and boosted radiation use efficiency by 21.9% under high density. In terms of grain yield, DHEAP treatment resulted in a 9.1% and 23.9% increase in ZD958 and XY335, respectively, under high-density conditions. These results suggest that DHEAP shaped the maize canopy structure with high density tolerance, improved the distribution of light within the canopy, and increased grain yield.

【Objective】The study was conducted to screen plant growth regulators that could shorten the plant height of banana without affecting the yield, and explore the dwarfing effects of their application times on banana plants. Furthermore, appropriate concentrations of uniconazole were detected for identifying the changes in the activities of several defensive antioxidant enzymes, and the contents of soluble protein, potassium, calcium, magnesium and phosphorus in banana leaves, to further analyze the positive auxiliary effect of uniconazole on banana plant growth in addition to dwarfing effect, which would provide references for the safe and rational use of plant growth regulators in banana production.【Method】The dwarfing effects of several plant growth regulators including uniconazole (XX), paclobutrazol (DX), chlormequat chloride (AZ), mepiquat (JP), compound agents 0802 and 0501 on banana plants were evaluated by root spraying method. The contents of polyphenol oxidase (PPO), superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia lyase (PAL), soluble protein, potassium, calcium, magnesium and phosphorus in banana leaves were determined after 15, 20 and 25 days of 0.3 g/plant XX treatment.【Result】According to the evaluation standard of dwarfing effect, banana plant could grow normally in the 3-5 level of internode distance after dwarfing. Under one dwarfing treatment, the banana plant heights of XX1, DX1, 0501, XX3, JP2, 0802, AZ1 and JP4 treatments were decreased by 11.67-24.00 cm. The banana plant heights of JP2, DX1, JP4, 0802, AZ1, 0501 and XX3 under two dwarfing treatments were decreased by 29.67-39.00 cm with normal growth. It found that the banana plant height was shortened with the increase of the concentrations and application times of these grow regulators. XX3, 0802 and 0501 treatments could promote the early bud shooting of banana, and the duration periods were 8-19 days earlier than that of the control; The plant shooting was neat. The shooting rate of XX3 under two drarfing and 0802 treatment was 62.01% and 89.32%. The yield per plant showed decreasing trends with the increase of XX concentration. The plant yields of banana were 27.26, 25.62 and 23.45 kg for the one time treatment of XX1, XX3 and XX5, respectively. Of which, the yields per plant of XX3 and XX5 treatment were significantly decreased compared with that of the control (27.45 kg). The yields per plant of banana treated with 0802 and 0501 were 27.37 and 26.99 kg, respectively, and there was no significant difference with that of the control. It was found that the yield performance of banana plants was similar under the two dwarfing treatments of different plant grow regulators. Under the treatment with low concentrations of chlormequat chloride and paclobutrazol, the early shooting of banana could be promoted. Whereas the shooting of banana was delayed when the treating concentration was above 0.2 g per plant, and the plant yield was greatly affected or even reduced. The uniconazole treatment could increase the activities of PPO, CAT and PAL in banana leaves as well as the contents of soluble protein, calcium, magnesium, phosphorus and potassium, and enhance plant resistance.【Conclusion】It is recommended to use uniconazole, compound agents 0802 and 0501 as banana dwarfing agents with concentration ranging of 0.2-0.3 g/plant in banana production, and the newly planted banana could be dwarfed once. Banana is more susceptible to paclobutrazol (DX) and chlormequat chloride (AZ), which are not recommended.

Plant growth regulators (PGRs) are a critical regulatory factor that influences plant development and against abiotic or biotic stress. The chemical synthesis of phytohormone analogues represents an effective approach for developing novel PGRs with enhanced bioactivity, reduced costs, and simplified synthesis. This review provides a comprehensive examination of artificially synthesized PGRs (phytohormone structural analogues and functional analogues) over the past five years, emphasizing the synthesis strategy, bioactivity, structure-activity relationships, and target protein. This review argues that the synthesis of functional analogues of phytohormones represents a crucial in the advancement of novel PGRs, and optimization of synthetic procedures would greatly facilitate the commercialization of these PGRs.

Auxin inactivation is critical for plant growth and development. To develop plant growth regulators functioning in auxin inactivation pathway, we performed a phenotype-based chemical screen in Arabidopsis and identified a chemical, nalacin, that partially mimicked the effects of auxin. Genetic, pharmacological, and biochemical approaches demonstrated that nalacin exerts its auxin-like activities by inhibiting indole-3-acetic acid (IAA) conjugation that is mediated by Gretchen Hagen 3 (GH3) acyl acid amido synthetases. The crystal structure of Arabidopsis GH3.6 in complex with D4 (a derivative of nalacin) together with docking simulation analysis revealed the molecular basis of the inhibition of group II GH3 by nalacin. Sequence alignment analysis indicated broad bioactivities of nalacin and D4 as inhibitors of GH3s in vascular plants, which were confirmed, at least, in tomato and rice. In summary, our work identifies nalacin as a potent inhibitor of IAA conjugation mediated by group II GH3 that plays versatile roles in hormone-regulated plant development and has potential applications in both basic research and agriculture.

Cannabis (Cannabis sativa) is a high-value crop, wherein growth within controlled environments is common for the purposes of maximising yield, quality, and uniformity, however, uncontrolled-growth in proximity to artificial lighting can compromise yields. Within the floricultural industry it is common practice to apply plant growth regulators (PGRs) to retard plant growth and maximise yield and quality, with two well-established PGRs being chlormequat chloride (CCC) and paclobutrazol (PBZ). Accordingly, the aim of this study was to investigate the potential of a PGR complex of CCC and PBZ for novel application to cannabis to control plant height. Treatment of cannabis with the PGR complex within an indoor hydroponic growth system resulted in a 91.1% reduction in post-treatment plant growth (p < 0.001) leading to plants with end-point height and internodal spacing (INS) 0.568-fold (p < 0.001) and 0.469-fold (p < 0.001) shorter than control plants, respectively. These results demonstrate the capacity of CCC and PBZ to beneficially halt the growth of cannabis. Accordingly, application of these PGRs in combination may be utilised to restrict cannabis height without compromising yield within commercial cultivation. [ABSTRACT FROM AUTHOR]

Salicylic acid is a phenolic plant growth regulator that affects the secondary metabolite production of medicinal plants. Moreover, Zinc is one of the necessary micronutrients that has a positive effect on the growth parameters and physiological characteristics of the plants. This study aimed to evaluate the interaction effects of foliar application (distilled water (as control), ethanol 1 % (as solvent), 1 and 2 mM salicylic acid), and zinc concentrations containing (0 (Zn omission), 0.025, 0.05, and 0.1 mgL−1) on the growth, phenolic compounds profile and antioxidant capacity of the peppermint. Results showed that response of most investigated traits to the application of zinc was differing with the levels of salicylic acid applications. In this experiment, variation among methods of antioxidant activity assay was observed. The highest antioxidant activity based on IC 50 (0.16 mg mL−1) was observed in Zn omission and 1 mM SA application. In contrast, the highest rosmarinic acid (34.23 ± 0.04 mg g DW−1) and gallic acid (14.99 ± 0.06 mg g DW−1), as the major PCs, were observed in 0.1 mgL−1 Zn and 1 mM SA application. SA application, as an elicitor, can enhance PCs and antioxidant activity of peppermint at the highest Zn level (0.1mgL−1) and Zn omission due to the stress condition of these Zn levels. Overall, these findings indicated that by increasing appropriate Zn levels and salicylic acid application, the accumulation of PCs and antioxidant activity of peppermint enhanced. [Display omitted] • Main phenolic compounds of peppermint were changed by salicylic acid and zin levels. • Antioxidant activity of peppermint affected by salicylic acid and zin treatments. • Rosmarinic acid increased by salicylic acid application in all zinc concentrations. • Rutin hydrate was known as main flavonoid constituent of peppermint. [ABSTRACT FROM AUTHOR]

This study investigated the effect of exogenous plant growth regulators (PGR), namely jasmonic acid (JA) and methyl jasmonate (MeJA), on the physicochemical properties of flesh and peels of red-fleshed dragon fruit (Hylocereus polyrhizus). The fruit was sprayed with 100 and 1,000 ppm of JA and MeJA at 15 and 22 days of anthesis and harvested after 35 days. Then, the flesh and peels were analyzed for total soluble solids (TSS), total betacyanins, betanin, total phenolics (TP), total flavonoids (TF), and color characteristics. The fruit peels contained significantly higher (p<0.05) TP and antioxidant activities compared to flesh. No significant difference was detected between the variables in the peels, except for significantly higher (p<0.05) of total betacyanins (~295.6 and ~299.9 mg/100 g) and TP (~614.1 and 566.1 mg GAE/100 g) were recorded in control and 100 ppm MeJA, respectively. In the flesh, 1,000 ppm MeJA-treated fruit possessed the highest total betacyanins (~139.2 mg/100 g), betanin (~356.0 mg/g), TP (~244.9 mg GAE/100 g), TF (~329.0 mg CE/100 g), Trolox equivalent antioxidant capacity (TEAC) (63.2 µmol TE/g) and reducing power (~21.5 µmol TE/g). Overall, 1,000 ppm MeJA was more effective in enhancing the accumulation of bioactive compounds and antioxidant activities in the flesh of red-fleshed dragon fruit compared to other PGR treatments. [ABSTRACT FROM AUTHOR]

The extensive use of atrazine to control weeds in agricultural areas has contaminated atrazine in surface water and groundwater. Atrazine contamination in water resources causes human health concerns. Thus, this study investigated the possible use of aquatic plants for removing atrazine from contaminated water. The experiment was performed under plant nursery conditions and divided into two parts: (1) the atrazine-tolerant plants were screened, and (2) the most atrazine-tolerant plant was used for atrazine phytoremediation stimulated by plant growth regulators. The results showed that atrazine was toxic to all aquatic plants, as the dry weight of the plants was significantly decreased when exposed to 20 mg/L of atrazine (P<0.05). Based on five aquatic plants grown under 2.5–20 mg/L atrazine-contaminated water, Azolla microphylla Kaulf. was the most tolerant aquatic plant and was more suitable for use in atrazine phytoremediation than the other aquatic plants (Ceratophyllum demersum L., Eichhornia crassipes (Mart.) Solms, Hydrilla verticillata (L. f.) Royle, and Salvinia cucullata Roxb. ex Bory). The total chlorophyll, carotenoid, and proline contents in the biomass of A. microphylla cultured in 2.5–20 mg/L of atrazine did not significantly differ between the atrazine concentrations (P>0.05). Meanwhile, the proline contents in the other four aquatic plants increased with increasing atrazine concentrations, and the chlorophyll content significantly decreased with an increase in the atrazine concentration. However, A. microphylla could not remove atrazine from contaminated water, and the application of plant growth regulators (6-benzyladenine, gibberellic acid, indole-3-butyric acid, and salicylic acid) did not improve the atrazine removal from water. Atrazine in the water was around 21–26 mg/L on day five of A. microphylla cultivation compared to the initial concentration (25 mg/L). Using a plant growth regulator was ineffective for stimulating growth and atrazine removal by A. microphylla. Future research should explore other potential mechanisms for enhancing atrazine removal by A. microphylla. [ABSTRACT FROM AUTHOR]

Walnuts are considered a functional food and play a significant role worldwide in people's regular diets. The cultivation and trade of walnut rootstocks and saplings are crucial agricultural activities globally and in Türkiye. Rootstocks are used for grafting and propagating different walnut varieties, and they are essential for tree development, fruit yield, product quantity, and most importantly, their ability to adapt to various ecological conditions and resist diseases and pests. Fruit growing and production of fruit rootstocks of deep-rooted plants in horticulture is given high importance in many countries. However, poor rooting and slow-growing sapling prevent establishing high-yield clonal production. Especially walnut sapling propagation is more complicated and timeconsuming than other woody plants. Our research aims to grow high-quality saplings by using biotechnological techniques. This study used modifications to the current in vitro basal medium and evaluated the effects on in vitro rooting and micrografting of walnut species. The optimal medium for shoots induction (2.93±0.90) of the plant was determined as 4 number medium (Murashige and Skoog (MS) nutrient medium with 5.4 µM NAA + 6.9 µM TDZ + 0.6 µM GA3 and solidified with 0.7% agar). In trials to develop sapling, the 10.33 and 6 rooted (2.5cm root length) shoots were obtained from MS nutrient medium with 14.7 and 19.6 µM of IBA and 348.42 µM of FeSO4.7H2O, and two micrografted plants in MS medium with 19.6 µM of IBA and 348.42 µM of FeSO4.7H2O survived. After three months in the growth chamber, six saplings were ready for transfer to the field. Our findings suggested that FeSO4.7H2O and high dose IBA treatment in MS medium is efficient for in vitro rooting and obtaining in vitro micrografted saplings. [ABSTRACT FROM AUTHOR]