PubMed HealthSearch

SEARCH · PubMed Health

Results for “Plant Growth Regulators”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

[Effect of several plant growth regulators on various prokaryotes and their viruses].

26 plant growth regulators including herbicides were investigated in their effect on the multiplication of Escherichia coli, Bacillus subtilis, and the blue-green alga Plectonema boryanum as well as the RNA phages M 12 and Qbeta and the DNA phages lambda, phi 105, and LPP-1 employing the agar diffusion method. Nearly all of the compounds inhibited and/or stimulated one or some of the prokaryotes tested. The most frequent and strongest effects occurred in Pl. boryanum, the least effects in E. coli. The multiplication of phages was also influenced by plant growth regulators leading to increase, decrease or non-appearance of plaques. The investigations with the temperate phages lambda and phi 105 suggested part of the compounds to be able to interfere with the process of lysogenization. The results are discussed comparatively involving correspondent findings referred to in literature.

Bacillus subtilis

Repression of asexual embryogenesis in vitro by some plant growth regulators.

A factor that represses asexual embryogenesis has been observed in the Rutaceae, with particularly high concentrations in the naturally monoembryonic cultivars. This investigation was an initial step towards identifying the factor. Citrus reticulata Blanco Ponkan mandarin nucellus explants and Daucus carota L. 'Queen Anne's Lace' callus were employed to examine effects of known plant growth regulators and to determine possible identity of one or more of them with the repressive factor. The chalazal halves of ovules of C. media L. 'Citron of Commerce' were used as control repressor source. Embryo initiation and growth of both test tissues were depressed markedly by 2,4-D, abscisic acid and ethephon. Slight inhibitions were obtained with IAA, kinetin and gibberellic acid. Recovery from the repressor did not occur readily in Citrus nucellus following recultures in citron-ovule-free medium; carrot callus resumed normal embryogenesis immediately upon transfer to suppressor-free medium. The repression by natural sources apparently involved the combined action of some or all natural hormones that are generically related to the above.

2,4-Dichlorophenoxyacetic Acid

Toxicity and plant growth regulator effects of cytochalasin H isolated from Phomopsis sp.

A biologically active metabolite was found in crude extracts of an unidentified species of Phomopsis isolated from weevil-damaged pecans. Purified metabolite was toxic to day-old cockerels, with an LD50 of 12.5 mg/kg, and was markedly inhibitory to growth the floral development of tobacco plants at concentrations of 10(-2) to 10(-4) M. IR and 1H-nmr spectra indicated an alkylpheny moiety with a single nitrogen atom present as a secondary amide; and acetate ester, OH, CH3, and a trans-double bond function. Elemental and high-resolution mass-spectral analysis indicated a formula of C30H39NO5 and a molecular weight of 493.2886. The metabolite was identified as cytochalasin H.

Animals

Brassinosteroids as Central Regulators of Plant Growth, Stress Tolerance, and Agricultural Resilience.

Brassinosteroids (BRs) are essential steroidal phytohormones that regulate plant growth, development, and responses to environmental stresses. Recent studies have demonstrated the important roles of BRs in enhancing plant tolerance to abiotic stresses, including drought, salinity, temperature extremes, heavy metal toxicity, and oxidative stress, as well as biotic stresses caused by pathogens and herbivores. This review summarizes current advances in BR biosynthesis, metabolism, transport, and signaling pathways, focusing on key components that mediate stress adaptation. We discuss the physiological and molecular mechanisms through which BRs improve stress tolerance, including regulation of antioxidant defense, ion homeostasis, osmotic adjustment, and stress-responsive gene expression. Particular attention is given to the extensive cross talk between BRs and other phytohormones, such as abscisic acid, jasmonic acid, salicylic acid, ethylene, auxin, and gibberellins, which enables plants to balance growth and defense under adverse conditions. Furthermore, we highlighted the potential applications of BRs in crop improvement through exogenous treatments, genetic engineering, and genome-editing approaches. However, the effectiveness of BR-based strategies is highly dependent on crop species, developmental stage, stress type, BR concentration, application method, and environmental conditions. In addition, excessive BR accumulation or application may result in undesirable growth responses, and further multi-location field validation is required before widespread agricultural implementation. Finally, we discuss emerging research trends, current knowledge gaps, and future perspectives for exploring BR signaling to develop climate-resilient crops. Overall, BRs represent promising targets for improving crop stress resilience; however, optimizing BR-mediated strategies and validating their long-term performance under diverse field conditions will be essential for their successful application in sustainable agriculture.

abiotic stress

[Possible use of growth regulators for plant processes in selected grain pod-vegetables].

The cultivation of beans and peas as grain legumes in large-scale production requires plants with a high yield and suitable for machine harvesting. Growth regulators for plant processes can also be applied to achieve these properties. The effect on the yield by growth regulators, as demonstrated in pot and field trials, seems to enable their application in an established intensive cultivation of beans and peas. Prior to this, however, it has to be demonstrated that these positive effects of growth regulator application can reproduced economically in different locations and with different species.

Agriculture

A stable transformation platform in pomegranate uncovers PgMYB10 as a key regulator of anthocyanin biosynthesis.

An efficient genetic transformation platform enables functional validation of PgMYB10, identifying it as a master regulator governing anthocyanin biosynthesis in pomegranate. Limited availability of stable genetic transformation systems restricts functional genomics research in pomegranate. Here, we established efficient in vitro regeneration and Agrobacterium tumefaciens-mediated transformation systems for 'Taishanhong' pomegranate using stem segment explants. Optimized medium combinations produced high-frequency regeneration: a 93.3% shoot-induction rate on MS medium with 1.5 mg/L 6-benzylaminopurine (BAP), 0.6 mg/L 1-naphthaleneacetic acid (NAA) and 30.0 mg/L adenine sulfate (ADS); a proliferation coefficient of 5.4 on MS medium supplemented with 0.8 mg/L BAP and 0.3 mg/L indole‑3‑butyric acid (IBA); effective shoot-strengthening on MS medium containing 1.2 mg/L BAP, 0.3 mg/L NAA and 0.2 mg/L gibberellic acid (GA₃); and a rooting rate of 95.3% on half-strength MS medium with 1.5 mg/L IBA and 0.5 mg/L NAA. For transformation, precultured explants were immersed with A. tumefaciens suspension (OD₆₀₀ = 0.8) containing 20.0 mg/L acetosyringone (AS) for 30 min. After four days of dark co-culture, sequential antibiotic screening with 30 mg/L kanamycin and bacteriostatic treatment with 400 mg/L timentin yielded a stable average transformation efficiency of 17.5% in 'Taishanhong' pomegranate. Subsequent functional analysis revealed that overexpression of PgMYB10 induced pigment accumulation in leaves and stems. In three independent transgenic lines, maximum anthocyanin content and PgMYB10 transcript levels were 5.4-fold and 27.2-fold higher than in wild-type plants, respectively. Six anthocyanin biosynthetic genes (PgCHS, PgCHI, PgF3H, PgDFR, PgANS, and PgUFGT) were markedly upregulated, demonstrating that PgMYB10 positively controls anthocyanin biosynthesis. This transformation system provides a reliable technical platform for functional genomic studies in pomegranate, and PgMYB10 represents as a promising candidate gene for molecular breeding aimed at improving fruit pigmentation.

Anthocyanins

The link between phosphate starvation-triggered anthocyanin biosynthesis and jasmonate-driven regulation in tomato.

Phosphate Starvation Response (PSR) in plants integrates inorganic phosphate (Pi) sensing with hormonal and metabolic reprogramming. Recent evidence supports a PSR-jasmonate (JA)-anthocyanin axis in which the PSR-associated PHOSPHATE STARVATION RESPONSE (PHR)/PHR-like-SYG1-PHO81-XPR1-inositol pyrophosphate 8 (PHR/PHL-SPX-InsP8) module gates transcriptional activation, while the core JA components JASMONATE ZIM-DOMAIN (JAZ) and MYELOCYTOMATOSIS 2 (MYC2) mediate hormone-induced activation of secondary metabolism. In Solanum lycopersicum, PHR/PHL transcription factors (TFs) serve as core PSR hubs, with expanded regulatory networks and InsP-associated control layers that tune SPX buffering and transcriptional output. Downstream, JA signaling and MYC2-dependent transcription interface with anthocyanin regulators, including key MYB and bHLH TFs that form the MYB-basic helix-loop-helix (bHLH)-WD40 repeat (MBW) complex, thereby regulating tissue capacity for pigmentation under Pi starvation (PiS). Anthocyanin-rich tomato cultivars such as 'Indigo Rose' exemplify how genetic configuration can enhance MBW responsiveness and potentiate pigment accumulation under PiS. Here, we collate recent advances linking PSR gating, JA response, and anthocyanin biosynthesis regulation in tomato, and propose a working model with testable predictions to accelerate causal validation, and enable breeding strategies targeting phosphorus use efficiency and nutritional quality.

Solanum lycopersicum

Benzoic acid inhibits peach root growth and lateral root emergence by disrupting auxin homeostasis through salicylic acid accumulation.

We established a non-sterile root transformation system in peach seedlings. Using this system, we demonstrated that BA treatment inhibits plant growth and lateral root emergence by SA-mediated disruption of auxin distribution. Allelopathic autotoxins, particularly benzoic acid (BA), are recognized as primary contributors to peach (Prunus persica) replant disease; however, the molecular mechanisms by which BA disrupts root development remain poorly understood. BA treatment significantly reduced stem and root length and inhibited lateral root emergence without affecting lateral root initiation. To investigate the underlying mechanism at cellular resolution, we established a non-sterile Agrobacterium rhizogenes-based root transformation system achieving 27.11% transformation efficiency. Auxin biosynthesis (PpYUC10), influx transport (PpAUX1), and response (PpARF19) genes were markedly downregulated following BA treatment. Transgenic roots expressing the DR5::GUS auxin reporter exhibited reduced DR5 activity in root tips and suppressed expression in tissues surrounding lateral root primordia, indicating impaired auxin signaling at both developmental sites. Hormone profiling revealed a non-significant trend toward reduced auxin metabolites alongside significant accumulation of salicylic acid (SA), an auxin-antagonistic hormone, and its storage conjugate SA 2-O-β-glucoside. Supporting a causal role for SA, exogenous SA phenocopied BA-induced root growth inhibition, whereas co-treatment with IAA or the SA-biosynthesis inhibitor aminoindan-1-phosphonic acid (AIP) significantly rescued lateral root number and root fresh weight. Multi-treatment RNA-seq identified "response to auxin" and "response to salicylic acid" as the most enriched GO terms in BA-treated roots, and AIP treatment restored the expression of key auxin-related genes while reversing BA-induced SA-pathway changes. Together, these findings suggest that BA-induced SA accumulation suppresses auxin biosynthesis, transport, and signaling, thereby inhibiting peach root growth and lateral root emergence. This study elucidates the molecular basis of BA autotoxicity and establishes a transformation platform for functional genomic studies in Prunus.

Indoleacetic Acids

[Requirements for the toxicological testing of new pesticides and agents for controlling biological processes].

Growing amounts of pesticides and plant growth regulators are being used in our time and call for action to ensure safety for man and farm animals. Toxicological rules and requirements are discussed with reference to the legal provisions in the USSR, USA, and FRG. Specifications for toxicological assessment of new preparations have been prepared in the GDR and Poland and are described. Particular emphasis is laid on studies into acute, subacute or subchronic, and chronic toxicity and delayed consequences. Conclusions are suggested and steps discussed to decide tolerances for food and feedstuffs.

Animals

Cytokinins.

Explore the source record for details and available documents.

Allosteric Regulation

The transcription factor NO TRANSMITTING TRACT/WIP2 modulates cytokinin homeostasis in Arabidopsis.

The transcription factor WIP2/NO TRANSMITTING TRACT (WIP2/NTT) belongs to the WIP zinc finger family. Loss of WIP/NTT function in Arabidopsis thaliana causes alterations in specific tissues in the gynoecium. It also impairs root development, but only when combined with the loss of WIP4 and WIP5 function, due to redundancy. Certain mutant loss-of-function phenotypes can be recovered by cytokinin application, NTT interacts with cytokinin signaling components, and the phenotypes displayed by plants with increased WIP2/NTT expression also suggest a possible interaction with this pathway. Therefore, the objective of this study was to investigate the relationship between WIP2/NTT and the cytokinin pathway. To overcome the issue of genetic redundancy, we used a commonly used inducible system. We found that WIP2/NTT induction alters cytokinin levels and signaling in a tissue-specific manner, as shown by cytokinin content measurements and TCSn::GFP reporter analysis. Transcriptome analyses revealed candidate target genes related to the cytokinin pathway. Yeast one-hybrid and transactivation assays demonstrated direct NTT binding to regulatory regions of the cytokinin genes ISOPENTENYL TRANSFERASE 5 (IPT5), ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 (AHP6), and CYTOKININ OXIDASE/DEHYDROGENASE 7 (CKX7) involved in cytokinin biosynthesis, signaling, and degradation, respectively. Moreover, immunolocalization assays revealed that cytokinin distribution was altered in loss of function mutants and after NTT induction. The results of this work indicate that WIP2/NTT modulates cytokinin homeostasis.

Cytokinins

A redox-regulated RCC1-like protein controls catalase activity in Arabidopsis.

Reactive oxygen species (ROS) regulate plant growth and stress responses. Catalases play a central role in detoxifying hydrogen peroxide, predominantly within peroxisomes, yet key aspects of catalase regulation remain incompletely understood. Using affinity purification of the UV-B photoreceptor UVR8 coupled with mass spectrometry, we identified CATALASE-INTERACTING RCC1-LIKE 1 (CAIR1), which interacts with all three Arabidopsis catalases and their chaperone NO CATALASE ACTIVITY 1. Loss of CAIR1 reduces catalase activity and causes oxidative stress sensitivity, impaired root growth, and alkaline sensitivity, resembling cat2 and nca1 mutants. CAIR1 promotes peroxisomal import and proper localization of CAT2, preventing CAT2 aggregation and maintaining its activity. CAIR1 undergoes reversible redox-dependent oligomerization that enhances catalase binding, whereas mutation of Cys-356 and Cys-545 compromises this interaction and fails to rescue the oxidative stress sensitivity of cair1 mutants. UV-B weakens CAIR1-catalase interactions and suppresses catalase activity, linking light signalling with redox homeostasis. These findings identify CAIR1 as a redox-responsive regulator of catalase localization and activity.

Arabidopsis

Preparation and characterization, using high-performance liquid chromatography, of an enzyme forming glucosides of cytokinins.

Cytokinins can occur naturally as glycosides with beta-D-glucose as the sugar substituent. From radish (Raphanus sativus) cotyledons, an enzyme has been partly purified which synthesizes the 7-glucopyranoside of zeatin [6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine], a compound known to occur in this species. High-performance reverse-phase liquid chromatography was uniquely useful as the analytical procedure for quantitative study of the minute amounts of enzyme available. The enzyme uses UDPglucose as the source of the sugar residue. A large number of derivatives of purine are glucosylated, but adenine derivatives with an alkyl side chain at least three carbon atoms in length at position N6 are preferentially glucosylated. This corresponds to the structural features required for high cytokinin activity. The 7-glucoside of zeatin is known to be very weakly active in cytokinin bioassays. Hence, this enzyme, and others catalyzing the same reaction, have a role in the regulation of cytokinin activity.

Cytokinins