Search Results (180)

Corn cockle (Agrostemma githago L. (Lychnis githago (L.) Scop.)) is the main ingredient in some plant preparations for biostimulation in agriculture, and it elicits many positive responses. In our study, we attempted to determine if the fresh and dry plant material of A. githago contained auxin-like and cytokinin-like growth regulators (PGRs). Cucumis and mung bean bioassays were used to determine the presence of auxin-like PGRs and Cucumis and Triticum bioassays were used to determine the presence of cytokinin-like PGRs. A water solution derived from the crushed, homogenized and extracted seeds, fresh and dry seedlings, and fresh and dry young plants showed auxin-like activity in both bioassays. The activity in the Cucumis bioassay corresponded to 0.5 to 2 mg L⁻¹ of Indole-3-butyric acid (IBA), and in the mung bean bioassay, the activity corresponded to 0.5 to 4 mg L⁻¹ of IBA. While the same water solutions showed weak or no cytokinin-like activity in the Cucumis cotyledon expansion bioassay, and they showed an activity of approximately 0.5 to 1 mg L⁻¹ of 6-Benzylaminopurine (BAP) in the Triticum bioassay. An LC-MS analysis confirmed the presence of free auxins, low levels of or no auxin analogues, a small amount of free cytokinins and a higher level of their cytokinin analogues in the samples, seeds, dry seedlings and young plants of A. githago, which was likely related to the fine-tuning between the free and analogue forms of the PGRs in the water solutions used in the experiments. Full article

Melastoma dodecandrum is primarily propagated through stem cuttings, which limits genetic variation and constrains breeding efforts. To overcome this limitation and facilitate molecular breeding, the establishment of a reliable and efficient regeneration system is essential. This study investigated the effects of plant growth regulators (PGRs) and culture media on the in vitro regeneration system of M. dodecandrum. The highest rate of callus induction (96.67%) was achieved when sterile leaf explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 2.00 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.50 mg·L⁻¹ 6-benzylaminopurine (6-BA). For callus differentiation, the optimal formulation of MS + 2.0 mg·L⁻¹ 6-BA + 0.5 mg·L⁻¹ naphthylacetic acid (NAA) resulted in a differentiation frequency of 83.33%. The optimal PGR combinations for shoot proliferation were 1.5 mg·L⁻¹ 6-BA + 0.1 mg·L⁻¹ NAA and 0.5 mg·L⁻¹ 6-BA + 0.2 mg·L⁻¹ NAA. The optimal rooting media were MS medium supplemented with 0.1, 0.2, or 0.5 mg·L⁻¹ indole-3-butyric acid (IBA) or 1/2MS medium supplemented with 0.1 mg·L⁻¹ IBA. Additionally, this study investigated the dynamic changes in endogenous hormones during the regeneration process. The levels and ratios of hormones, including gibberellin (GA₃), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (ZT), collectively regulated the regeneration process. Elevated levels of ABA and GA₃ may promote callus initiation as well as the growth and development of adventitious roots during the early induction stage. Reduced levels of ABA and IAA favored callus differentiation into shoots, whereas elevated GA₃ levels facilitated proliferation of adventitious shoots. Throughout the regeneration process, fluctuations in ZT levels remained relatively stable. This study successfully established an in vitro regeneration system for M. dodecandrum using leaf explants, providing theoretical guidance and technical support for further molecular breeding efforts, genetic transformation, and industrial development. Full article

Plant growth regulators (PGRs) enhance crop stress resistance but their roles in microbial-mediated phosphorus cycling within intercropping systems are unclear. Thus, We conducted a two-year field study using corn (Zea mays L. cv. Denghai 605) and soybean (Glycine max L. cv. Hedou 22) in fluvisols and luvisols soil according to World Reference Base for Soil Resources (WRB) standard. Under a 4-row corn and 6-row soybean strip intercropping system, three treatments were applied: a water control (CK), and two plant growth regulators—T1 (EC: ethephon [300 mg/L] + cycocel [2 g/L]) and T2 (ED: ethephon [300 mg/L] + 2-Diethyl aminoethyl hexanoate [10 mg/L]). Foliar applications were administered at the V7 stage (seventh leaf) of intercropped corn plants to assess how foliar-applied PGRs (T1/T2) modulated the soil phosphorus availability, microbial communities, and functional genes in maize intercropping systems. PGRs increased the soil organic phosphorus and available phosphorus contents, and alkaline phosphatase activity, but not total phosphorus. PGRs declined the α-diversity in fluvisols soil but increased the α-diversity in luvisols soil. The major taxa changed from Actinobacteria (CK) to Proteobacteria (T1) and Saccharibacteria (T2) in fluvisols soil, and from Actinobacteria/Gemmatimonadetes (CK) to Saccharibacteria (T1) and Acidobacteria (T2) in luvisols soil. Functional gene dynamics indicated soil-specific regulation, where fluvisols soil harbored more phoD (organic phosphorus mineralization) and relA (polyphosphate degradation) genes, whereas phnP gene dominated in luvisols soil. T1 stimulated organic phosphorus mineralization and inorganic phosphorus solubilization in fluvisols soil, upregulating regulation genes, and T2 enhanced polyphosphate synthesis and transport gene expression in luvisols soil. Proteobacteria, Nitrospirae, and Chloroflexi were positively correlated with organic phosphorus mineralization and polyphosphate cycling genes, whereas Bacteroidetes and Verrucomicrobia correlated with available potassium (AP), total phosphorus (TP), and alkaline phosphatase (ALP) activity. Thus, PGRs activated soil phosphorus by restructuring soil type-dependent microbial functional networks, connecting PGRs-induced shifts with microbial phosphorus cycling mechanisms. These findings facilitate the targeted use of PGRs to optimize microbial-driven phosphorus efficiency in strategies for sustainable phosphorus management in diverse agricultural soils. Full article

Hops (Humulus lupulus L.) are a critical component in beer brewing. The growing demand for craft beer has increased interest in hop cultivation in non-traditional regions where unfavorable climatic conditions hinder optimal yield and quality. To address these challenges, this study investigates the effects of plant growth regulators (PGRs) on hop cone yield and chemical compositions. In two separate studies, year-1 Cascade hops were subjected to various PGR treatments in the field. PGR treatments generally had minimal effect on the dry cone yield in study I. In study II, a combination of Ethephon at 45 mg/L and ProGibb at 3 mg/L significantly increased the cone yield by 125% compared to the control. While all treatments had a “good quality” hop storage index, a combination of Ethephon and ProGibb produced alpha acid percentages within the commercial standard range. Ethephon at 30 mg/L combined with ProGibb at 2 mg/L enhanced bitterness and aroma, delivering the highest concentration of volatile organic compounds at 569.7 mg/L, thereby enhancing aroma compounds associated with fruity esters, monoterpenes, and sesquiterpenes. This study demonstrates that specific PGR treatments can improve the chemical composition of hops grown in non-traditional regions, with implications for optimizing aroma and bitterness in beer. Full article

Brassinosteroids (BRs) are plant growth regulators (PGRs) with pleiotropic effects on plant growth and development. They play a role in seed germination, vegetative and reproductive growth, photosynthetic efficiency, vascular differentiation, fruit yield, quality, and resilience to biotic and abiotic stresses. They engage in crosstalk with other hormones like auxin, gibberellins, ethylene and abscisic acid, influencing all plant growth and development aspects. Studies on the effect of BRs on the reproductive growth of fruit crops are accumulating, given the potential of this PGR as a management tool in agriculture. This review explores the multifaceted roles of BRs in fruit crop maturation. From their biosynthesis and signal transduction pathways to their influence on fruit production, development, and maturation, we focus on the effect of this plant hormone on different aspects of fruit yield and quality, including fruit set and firmness, sugar accumulation, and fruit development. We address BRs’ interaction with different hormones at molecular and physiological levels in regulating these processes in climacteric and non-climacteric fruits. We also identify areas where knowledge is still lacking regarding hormonal crosstalk involving BRs in the regulation of developmental processes governing fruit quality and yield so knowledge generated can inform management decisions in fruit crop production. Full article

Chicory (Cichorium intybus L.) roots are valued in medicine for their potential health benefits. Producing callus from chicory roots through tissue culture technology can streamline bioactive metabolites production and ensure a sustainable supply chain. The current study explored the impact of plant growth regulators (PGRs) and light conditions on the characteristics of callus induced from C. intybus root explants. The effect of fungal elicitors [yeast extract (YE), Fusarium oxysporum, and Aspergillus niger] on bioactive metabolite production from root-derived callus was investigated. Callus color varied notably between a 16/8 h light/dark cycle and complete dark, with differences in texture based on PGR concentrations and light conditions. High weights of callus formed were generally recorded under the 16/8 h light/dark cycle. Low concentrations of YE (1 g/L) and F. oxysporum (0.25 g/L) enhanced callus biomass fresh weight, while high concentrations of A. niger (1 g/L) improved callus dry matter significantly. The content and productivity of total phenolic were maximized at 1 g/L of YE and 1 g/L of F. oxysporum. Callus cultures elicited with a higher level of A. niger recorded the higher values of total flavonoid production. High-performance liquid chromatography (HPLC) analysis revealed significant variations in chlorogenic acid, catechin, and caffeic acid levels among the different elicited cultures. A. niger at 1 g/L notably increased chlorogenic acid content, while catechin levels were enhanced by specific concentrations of YE. Catalase (CAT) activity was significantly affected by different elicitors, while only the higher level of F. oxysporum and A. niger showed a significant increase in peroxidase (POD) activity. DPPH scavenging activity was elevated by all fungal elicitors. Principal Component Analysis delineated distinct variations in callus traits in response to different elicitors, with specific treatments showcasing enhanced biomass production, bioactive compound accumulation, and antioxidant activities. Through meticulous experimentation, this study paves the way for enhancing chicory root-derived products, ensuring sustainable production and potent bioactivity. Full article

Triadica sebifera, an economically and medicinally valuable tree species native to China, was investigated for its in vitro regeneration potential using leaf explants from nodal cuttings of young stems and sprouts. This study evaluated the effects of basal media, plant growth regulators (PGRs), explant sources, and incision methods on adventitious shoot induction, supplemented by histological analysis. The highest shoot regeneration frequency (98.89%) and maximum shoot number (72) were achieved via direct organogenesis using sucker-derived nodal cuttings cultured on MS medium with 2 mg/L 6- benzyladenine (6-BA), 0.3 mg/L kinetin (KT), and 0.2 mg/L α-naphthaleneacetic acid (NAA). Under identical conditions, branch-derived explants showed lower regeneration (84.44%, 64 shoots). Transverse midvein incision proved most effective, with sucker-derived leaves exhibiting superior regeneration. Shoots elongated completely (100%) on Murashige and Skoog (MS) medium containing 0.3 mg/L 6-BA, 0.03 mg/L NAA, and activated charcoal. Rooting was optimal on MS medium with 0.3 mg/L indole-3-butyric acid (IBA), yielding a 98% acclimatization survival rate. Histological analysis revealed de novo meristem formation from parenchyma cells, confirming direct organogenesis without callus intermediation, further validating the enhanced regenerative capacity of sprout-derived explants. This efficient in vitro regeneration system provides a foundation for large-scale propagation and germplasm conservation of T. sebifera, while offering insights for woody plant regeneration studies. Full article

Excessive shoot vigor in grapevines negatively impacts plant growth and fruit quality, necessitating the use of plant growth regulators (PGRs) for canopy management. This study investigated the effects of mepiquat chloride (MC) and chlormequat chloride (CCC) on shoot growth (including new shoot length, relative chlorophyll content, leaf area, etc.) and fruit quality in Vitis vinifera cv. ‘Shine Muscat’. Different concentrations of MC (100, 300, 500, 700 mg/L) and CCC (100, 300, 500, 700 mg/L) were applied via foliar spraying at multiple stages before flowering. The results demonstrated that both PGRs effectively suppressed shoot elongation, with CCC exhibiting superior inhibitory efficacy compared to MC. However, high concentration of either compound also restricted leaf and cluster development. Optimal treatments MC (500 mg/L) and CCC (100 mg/L) significantly enhanced berry size, soluble solids content (SSC), and solid–acid ratio while maintaining effective shoot control. For practical application, we recommend spraying MC (500 mg/L) or CCC (100 mg/L) during the new shoot growth, flower-cluster separation, and flowering stages of ‘Shine Muscat’ grapevines to improve the new shoot control effect and fruit quality. Full article

This study aimed to assess the production of Smilax brasiliensis seedlings in an in vitro environment and their adaptation to natural conditions, as well as the callus induction, the chemical profile of calli extracts, and their antioxidant potential. The seedlings were obtained from S. brasiliensis seeds germinated in Murashige and Skoog (MS) medium. The germination rate was 33%, and about 22% of the seeds produced whole seedlings. Three-month-old seedlings were acclimatized for two months, resulting in an 80% survival rate and improved physiological characteristics. Callus induction was initiated from leaf explants obtained from seedlings and plant growth regulators (PGRs), with and without light exposure. Calli extracts were obtained using methanol; phenolic compound and flavonoid quantification were performed, and the chemical profile was determined by nuclear magnetic resonance (¹H NMR). For comparison, methanol extract from S. brasiliensis leaves collected in Brazilian Cerrado were also analyzed. Antioxidant activity was assessed using the 2,2-diphenyl-1-picryl-hydrazyl method and the ferric-reducing antioxidant power assay. All samples exhibited antioxidant activity according to the methods employed. Furthermore, ¹H NMR revealed metabolic profile changes in the calli extracts compared to the leaf extract. This study yielded promising results, suggesting that in vitro culture could improve productivity and conserve the species, although changes were observed in the metabolic profile of S. brasiliensis. Full article

Gibberellic acid (GA3) may help to synchronize coffee flowering, whilst ethylene (in the form of Ethephon) may assist in advancing coffee berry maturation even when applied in the pre-flowering stage of phenophase. Functional–structural plant modeling (FSPM) can be used to help understand whole-plant responses, such as plant-scale photosynthesis. FSPM has never been used to investigate the response of coffee plants to external plant growth regulator (PGR) applications. We hypothesized that treatment with PGRs at the beginning of berry maturation (BM) during phenophase could (1) influence plant leaf area and plant photosynthesis at the end of BM and (2) assist in the uniformity of the berry maturation of seven-year-old coffee plants. Additionally, we assumed that (3) the distribution of berries over the vertical plant profile could be related to the coffee beans’ chemical quality, and that irrigated plants would have delayed maturation, but a higher yield than non-irrigated (NI) plants. To test these hypotheses, a short sustainable period of irrigation was applied six weeks before harvest. Irrigated plants were treated with GA3 or Ethephon. A combination of field measurements (leaf gas exchanges, berry collection and bean chemical analyses in relation to vertical plant strata) and computer modeling were used. At the beginning or the end of BM, coffee trees were coded using the VPlants modeling platform and reconstructed using CoffePlant3D software to compute the plant leaf area and plant photosynthesis. The greatest number of second-order red berries were found in the upper stratum, S3 (>160 cm), while slightly fewer were found in S2 (80–160 cm) belonging to the third-order axes, and the lowest number was found in S1 (<80 cm). Green berries were more representative in S2, with the greatest number belonging to the third-order axes. The participation of third-order axes in berry yield was up to approximately 37% for red berries and 25% for green berries. The greatest separation between PGRs could be seen in S2, where more berries in the Ethephon-treated plants were found than in the GA3 treated ones, while the dry mass (DM) percentage was higher in GA3 than in the Ethephon treatment. The percentage of DM in fresh mass was 17–28% in the green berries and 28–36% in the red berries. PGRs were important for homogenous berry maturity, especially GA3, which also showed the lowest total chlorogenic acid content. The NI plants showed reduced red and total berry production when compared to irrigated ones, indicating this horticultural measure is important, even during a sustainably reduced six-week period, due to preserved leaf area and plant photosynthesis, and it also increased the lipid and kahweol contents of irrigated plants when compared to NI plants, despite the maturation delay. Full article

Soybean production in the southern Great Plains (SGP) faces challenges due to yield-limiting factors, including high temperatures and inconsistent precipitation. These conditions can lead to excess vegetative growth, similar to what occurs in crops like cotton. Management strategies utilizing plant growth regulators (PGRs) have been applied to control this excessive growth, yet there is limited information on methods to mitigate vegetative growth in soybeans through modifications to the apical meristem. Field trials conducted in 2022 and 2023 investigated the effects of altering the apical growth using Ascend SL, Compact, Cobra, Cygin Pro, and physical removal, with treatments applied at the V4 and R2 growth stages. This study highlights the significance of customized application strategies to enhance profitability under diverse environmental conditions. Ascend and Cygin Pro demonstrate improving yield stability under adverse climatic conditions. Both applications of Compact produced relatively stable yields across site years, while Cobra and physical removal methods necessitate careful consideration of timing to minimize yield losses. Further research is essential to optimize these management strategies for soybean production in the SGP. Full article

Embryos propagated from vegetative organs can maintain the excellent characteristics of the ortet tree and can make full use of the advantages of somatic embryogenesis technology in the large-scale clonal propagation of forest trees. However, in forest trees, a major obstacle to reproducing seedlings through somatic embryogenesis is the challenge of inducing somatic embryos using vegetative organs as explants. In this study, we have successfully developed a procedure to induce somatic embryogenesis (SE) in adult hybrid sweetgum trees for the first time. Leaves, petioles, and stem segments isolated from test-tube seedlings of three genotypes of hybrid sweetgum trees were used as explants to induce SE. The induction of SE was significantly influenced by genotype, explant type, and medium composition. The highest induction and proliferation efficiencies were achieved using a modified Blaydes’ medium supplemented with 1.0 mg/L 2,4-D and 0.5 mg/L 6-BA. Mature somatic embryos were obtained in media without plant growth regulators (PGRs). Among the three genotypes, only FX-12 failed to induce somatic embryos in all the explants. Petiole explants of FX-2 yielded 22 somatic embryos per gram. In FX-54, somatic embryos were induced from both leaf and petiole explants. The PGR concentration in the germination medium significantly affected the efficiency of somatic embryo germination, with the best germination results observed in modified Blaydes’ medium containing 0.5 mg/L 6-BA. This procedure resulted in over 60% of somatic embryos developing normally into plantlets. This study develops an SE system using vegetative organs as explants for the first time, providing technical support for large-scale asexual propagation and molecular breeding in hybrid sweetgum. Full article

The soybean yield per unit area in Xinjiang has reached a high level, with the crop maturing quickly because of the higher temperatures and levels of mechanization. However, environmental factors cause flowers and pods to shed easily, limiting yield potential. Efficient plant growth regulators (PGRs) used to increase crop yields have gained popularity, but their effectiveness in reducing flower and pod shedding, considering factors such as environment, crop variety, and time of spraying, remains unclear. This study investigated whether spraying several PGRs could reduce soybean flower and pod shedding. Field experiments were conducted from 2022 to 2024 in Ili, Xinjiang, China, using α-naphthaleneacetic acid (NAA), prohexadione-calcium (Pro-Ca), and iron chlorine e6 (ICE6) with foliar applications of 300, 450, and 45 g ha⁻¹ at the four-node stage (V4) and full pod stage (R4). All PGR treatments reduced flower and pod shedding over the years and resulted in an increase in the average flower and pod numbers compared to normal-growth-treated (CK) soybeans. The effective slowing of flower and pod shedding during the critical pod formation stage (R4) ensured a stable yield potential. The flower-to-pod conversion rate was higher after spraying plants with PGRs than for the CK group, and pod retention was higher at the beginning of maturity (R7). Our results demonstrated that spraying PGRs (NAA, Pro-Ca, and ICE6) effectively reduced soybean flower and pod shedding, optimized pod distribution, and increased soybean yield potential. The study findings provide a useful reference for global soybean growers to optimize planting methods. Full article

In vitro anther culture is a technique used to produce haploid plants when regenerating varieties with specific traits. To generate haploid plants with preferred characteristics, an anther culture technique was established for Lilium longiflorum “Show Up”. Morphological characteristics were recorded, including the flower bud length and anther color corresponding to different stages of microspore development. The effects of different flower bud lengths, various concentrations of exogenous plant growth regulators (PGRs), low-temperature pretreatment at 4 °C, and incubation under dark conditions on the induction of callus formation were studied. When the flower buds were 2.2–2.4 cm in length and the microspores were in the mononuclear development phase, callus induction reached the highest rate (15.6%). Callus was not induced when the PGRs 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KT) were added separately to the growth medium, but the highest callus induction rate occurred when anthers were cultured on the medium containing 2,4-D (0.75–1.0 mg/L) and KT (4 mg/L). The low-temperature pretreatment significantly enhanced the induction rate of anthers, but prolonged low-temperature pretreatment reduced the induction rate. The optimal period of cultivation in darkness was 6 d. After 15 days of cultivation, the number of swollen anthers was recorded, and these were transferred onto the differentiation medium Murashige and Skoog (MS) + 1-naphthaleneacetic acid (NAA) (2.0 mg/L), sucrose (30 g/L), and agar (7 g/L) at pH 5.8, whereon 100% differentiation was recorded. Overall, 14 regenerated lines were obtained by in vitro anther culture. Chromosome ploidy was determined by counting chromosomes in the root tips of ten regenerated plants, and four were found to be haploids. This study lays the foundation for anther culture in lilies to shorten the breeding cycle, improve selection efficiency, facilitate efficient genetic transformation, and enable the effective production of both haploid and double-haploid plants. Full article

Human nutrition is inherently associated with the cultivation of vegetables, grains, and fruits, underscoring the critical need to understand and manipulate the balance between vegetative and reproductive development in plants. Despite the vast diversity within the plant kingdom, these developmental processes share conserved and interconnected pathways among angiosperms, predominantly involving age, vernalization, gibberellin, temperature, photoperiod, and autonomous pathways. These pathways interact with environmental cues and orchestrate the transition from vegetative growth to reproductive stages. Related to this, there are two key genes belonging to the same Phosphatidylethanolamine-binding proteins family (PEBP), the FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1), which activate and repress the floral initiation, respectively, in different plant species. They compete for transcription factors such as FLOWERING LOCUS D (FD) and 14-3-3 to form floral activation complexes (FAC) and floral repression complexes (FRC). The FT/TFL1 mechanism plays a pivotal role in meristem differentiation, determining developmental outcomes as determinate or indeterminate. This review aims to explore the roles of FT and TFL1 in plant architecture and floral induction of annual and perennial species, together with their interactions with plant hormones. In this context, we propose that plant development can be modulated by the response of FT and/or TFL1 to plant growth regulators (PGRs), which emerge as potential tools for mitigating the adverse effects of environmental changes on plant reproductive processes. Thus, understanding these mechanisms is crucial to address the challenges of agricultural practices, especially in the face of climate change. Full article