Search Results (23)

Carnation (Dianthus caryophyllus L.) is a globally important cut flower, and its postharvest longevity is a key determinant of commercial value. Flower senescence in carnation is a genetically programmed yet environmentally modulated process involving coordinated physiological, biochemical, hormonal, and molecular changes. This review synthesizes recent advances in the regulation of carnation petal senescence, with a particular focus on ethylene (ETH)-dependent signaling, hormonal crosstalk, metabolic regulation, and emerging molecular control layers. ETH acts as the central regulator of senescence, interacting with abscisic acid, cytokinins, gibberellins, and auxins to control the timing and progression of petal aging. Recent studies have identified key regulatory genes, including DcACS1, DcACO1, DcEIL3-1, DcWRKY75, DcNAP1/2, DcATX1, and m⁶A methylation-related factors, revealing multilayered control of senescence progression. Emerging evidence further demonstrates that RNA m⁶A modification links ETH signaling with antioxidant capacity and metabolic homeostasis. We propose an integrated regulatory network model that connects hormonal crosstalk, environmental cues, transcriptional control, and post-transcriptional regulation. This updated framework provides mechanistic insights into developing targeted postharvest treatments and breeding strategies to extend vase life of cut carnation flowers. Full article

Fruit size is a key economic trait in horticultural crops, determined by an integrated network of genetic, hormonal, epigenetic, and environmental factors. This review synthesizes recent advances in understanding this regulation. Genetically, key quantitative trait loci (QTLs) such as fw2.2, fw3.2, FAS, and LC control cell number and organ size. Hormones including auxin, gibberellin, cytokinin, and brassinosteroid regulate cell division and expansion. Transcription factors (e.g., YABBY, WOX families) and epigenetic mechanisms (DNA methylation, histone modifications, endoreduplication) provide additional regulatory layers. Environmental factors (light, temperature, water, nutrition) and cultivation practices (pruning, thinning) ultimately shape the final fruit phenotype. Emerging technologies like multi-omics, CRISPR-Cas9 gene editing, and artificial intelligence offer powerful tools for future research and molecular breeding, which aim to decode the complex regulatory network and enhance crop yield and quality. Full article

Saccharina japonica (S. japonica) is a large-scale intertidal aquatic plant that exhibits characteristics such as rhizoid, holdfast, and blade differentiation. It demonstrates remarkable environmental adaptability. However, compared with higher plants, details about its phytohormone content, distribution, synthesis, and accumulation remain poorly understood. In this study, the phytohormone contents distribution and expression patterns of synthetic genes in different parts of S. japonica, including the rhizoid, petiole, basis, middle, and tip, were analyzed in detail by combining targeted metabolomics and transcriptomics analyses. A total of 20 phytohormones were detected in S. japonica, including auxin, abscisic acid (ABA), cytokinin (CTK), ethylene (ETH), gibberellin (GA), jasmonate acid (JA), and salicylic acid (SA), with significant site-differentiated accumulation. ABA and JA were significantly enriched in the tips (28.01 ng·g⁻¹ FW and 170.67 ng·g⁻¹ FW, respectively), whereas SA accumulated specifically only in the rhizoid. We also identified 12 phytohormones, such as gibberellin A1, methyl jasmonate, and trans-zeatin for the first time in S. japonica. Transcriptomic profiling revealed the tissue-specific expression of phytohormone biosynthesis genes, such as CYP735A (CTK synthesis), in the rhizoids and LOX/NCED (JA/ABA synthesis) in the tips. Key pathways, such as carotenoid biosynthesis and cysteine methionine metabolism, were found to be differentially enriched across tissues, aligning with hormone accumulation patterns. Additionally, an enrichment analysis of differentially expressed genes between various parts indicated that different parts of S. japonica performed distinct functions even though it does not have organ differentiation. This study is the first to uncover the distribution characteristics of phytohormones and their synthetic differences in different parts of S. japonica and elucidates how S. japonica achieves functional specialization through non-specific phytohormone regulation despite lacking organ differentiation, which provides an important theoretical basis for research on the developmental biology of macroalgae and their mechanisms of response to adversity. Full article

Epigeal cotyledons with excised embryonic axes are often used as a model system to study the processes of cell division and expansion. These processes are regulated by diverse phytohormones and signaling molecules. Phytohormones modulate antioxidant defense systems and interact with reactive oxygen species (ROS) to synchronize normal plant cell growth. This study provides new information concerning alterations in enzymatic antioxidants linked to the production and scavenging of ROS in excised epigeal cotyledons of zucchini grown on solutions of methyl jasmonate (MeJA) and cytokinins (CKs)—N⁶-benzyl adenine and N₁-(2-chloropyridin-4-yl)-N₂-phenylurea—in the presence or absence of light under laboratory conditions. The cotyledon material was used to determine the dynamics of selected biochemical parameters starting from the 2nd to the 6th day of incubation. In general, our results revealed that exogenous MeJA caused a reduction in the content of hydrogen peroxide (H₂O₂) and free proline, as well as in the activity of superoxide dismutase (SOD), guaiacol peroxidase (POX) and catalase (CAT) in dark-grown cotyledons. Applied alone, both cytokinins increased most of the parameters studied, except proline and protein levels. However, when MeJA was combined with CKs, it acted in a diverse manner, ranging from antagonistic to synergistic depending on the cytokinin type, parameter measured and light regime. Similar alterations were also found in the levels of leaf pigments in the cotyledons grown under light conditions. In general, the changes in the antioxidant enzyme activities due to light were more intense than those observed in dark-grown cotyledons. The data obtained show, for the first time, the involvement of the hormonal interplay between MeJA and CKs on the biochemical changes in antioxidant defense during cotyledon growth under different light conditions. Full article

The cytokinin (CK) type B response regulator (RRB) gene is involved in the CK signaling pathway and performs a key function for mediating reactions to amounts of abiotic stresses. Nevertheless, the RRB gene family remains to be characterized in Poaceae (also known as Gramineae or grasses). Here, we performed a comprehensive analysis encompassing phylogenetic relationships, evolutionary pressures, and expression patterns of the RRB gene family in six Poaceae species, including rice, Panicum, Sorghum, Setaria, maize, and wheat. Phylogenetic tree and syntenic analyses revealed that the RRB genes were divided into seven orthologous gene clusters (OGCs), indicating that the common ancestor of these Poaceae species possessed at least seven RRB genes. Further analysis revealed that the evolution of the Poaceae RRB gene family was primarily driven by purifying selection. The expression pattern of rice OsRRB toward phytohormonal and abiotic stresses was also investigated. The findings revealed that several phytohormones, including cytokinin (CK), abscisic acid (ABA), and methyl jasmonate (MeJA), as well as abiotic factors such as drought and cold, significantly increased the expression levels of these genes. Importantly, haplotype analysis identified four crucial variation sites within the OsRRB5 genomic regions that may contribute to drought resistance in rice. Our findings lay the groundwork for further elucidating the biological function of OsRRB genes and provide a promising new target for developing stress-resistant rice varieties. Full article

Terpenoids, abundant and structurally diverse secondary metabolites in plants, especially in conifer species, play crucial roles in the plant defense mechanism and plant growth and development. In Pinus massoniana, terpenoids’ biosynthesis relies on both the mevalonate (MVA) pathway and the 2-methyl-D-erythritol-4-phosphate (MEP) pathway, with 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase (HDS) catalyzing the sixth step of the MEP pathway. In this study, we cloned and conducted bioinformatics analysis of the PmHDS gene from P. massoniana. The results showed that PmHDS shares homology with HDS proteins from other species. Analysis of tissue expression patterns indicated that PmHDS exhibits the highest expression level in xylem tissue, followed by stems, with significantly lowest expression in the apical meristem. Treatment with NaCl, abscisic acid (ABA), ethylene (ETH), methyl jasmonate (MeJA), and salicylic acid (SA) upregulated the expression of PmHDS. Furthermore, we successfully cloned the PmHDS promoter (about 2220 bp) and integrated it into a GUS reporter vector, which resulted in GUS activity being observed in various tissues of Arabidopsis thaliana. Overexpression of the PmHDS gene in A. thaliana significantly increased the content of carotenoids, chlorophylls a and b, and related enzyme activities, as well as the levels of terpenoid derivatives such as cytokinin (CTK), gibberellic acid (GA), and ABA, thereby enhancing the resistance to those abiotic stresses. These findings suggest that PmHDS plays an important role in the terpenoid synthesis pathway. This study provides a theoretical basis for understanding the biosynthesis of terpenoids and lays a foundation for future research on the regulation of terpene synthesis and resistance in molecular breeding. Full article

Here, cytosine methylation in the whole genome of pear flower buds was mapped at a single-base resolution. There was 19.4% methylation across all sequenced C sites in the Pyrus pyrifolia cultivar ‘Sucui 1’ flower bud genome. Meantime, the CG, CHG, and CHH sequence contexts (where H = A, T or C) exhibited 47.4%, 33.3%, and 11.9% methylation, respectively. Methylation in different gene regions was revealed through combining methylome and transcriptome analysis, which presented various transcription trends. Genes with methylated promoters exhibited lower expression levels than genes with non-methylated promoters, while body-methylated genes displayed an obvious negative correlation with their transcription levels. The methylation profiles of auxin- and cytokinin-related genes were estimated. And some of them proved to be hypomethylated, with increased transcription levels, in wizened buds. More specifically, the expression of the genes PRXP73, CYP749A22, and CYP82A3 was upregulated as a result of methylation changes in their promoters. Finally, auxin and cytokinin concentrations were higher in wizened flower buds than in normal buds. The exogenous application of paclobutrazol (PP333) in the field influenced the DNA methylation status of some genes and changed their expression level, reducing the proportion of wizened flower buds in a concentration-dependent manner. Overall, our results demonstrated the relationship between DNA methylation and gene expression in wizened flower buds of P. pyrifolia cultivar ‘Sucui 1’, which was associated with changes in auxin and cytokinin concentrations. Full article

The elongation of the mesocotyl plays an important role in the emergence of maize deep-sowing seeds. This study was designed to explore the function of exogenous salicylic acid (SA) and 6-benzylaminopurine (6-BA) in the growth of the maize mesocotyl and to examine its regulatory network. The results showed that the addition of 0.25 mmol/L exogenous SA promoted the elongation of maize mesocotyls under both 3 cm and 15 cm deep-sowing conditions. Conversely, the addition of 10 mg/L exogenous 6-BA inhibited the elongation of maize mesocotyls. Interestingly, the combined treatment of exogenous SA–6-BA also inhibited the elongation of maize mesocotyls. The longitudinal elongation of mesocotyl cells was the main reason affecting the elongation of maize mesocotyls. Transcriptome analysis showed that exogenous SA and 6-BA may interact in the hormone signaling regulatory network of mesocotyl elongation. The differential expression of genes related to auxin (IAA), jasmonic acid (JA), brassinosteroid (BR), cytokinin (CTK) and SA signaling pathways may be related to the regulation of exogenous SA and 6-BA on the growth of mesocotyls. In addition, five candidate genes that may regulate the length of mesocotyls were screened by Weighted Gene Co-Expression Network Analysis (WGCNA). These genes may be involved in the growth of maize mesocotyls through auxin-activated signaling pathways, transmembrane transport, methylation and redox processes. The results enhance our understanding of the plant hormone regulation of mesocotyl growth, which will help to further explore and identify the key genes affecting mesocotyl growth in plant hormone signaling regulatory networks. Full article

Pinellia ternata is a medicinal plant that has important pharmacological value, and the bulbils serve as the primary reproductive organ; however, the mechanisms underlying bulbil initiation remain unclear. Here, we characterized bulbil development via histological, transcriptomic, and targeted metabolomic analyses to unearth the intricate relationship between hormones, genes, and bulbil development. The results show that the bulbils initiate growth from the leaf axillary meristem (AM). In this stage, jasmonic acid (JA), abscisic acid (ABA), isopentenyl adenosine (IPA), and salicylic acid (SA) were highly enriched, while indole-3-acetic acid (IAA), zeatin, methyl jasmonate (MeJA), and 5-dexoxystrigol (5-DS) were notably decreased. Through OPLS-DA analysis, SA has emerged as the most crucial factor in initiating and positively regulating bulbil formation. Furthermore, a strong association between IPA and SA was observed during bulbil initiation. The transcriptional changes in IPT (Isopentenyltransferase), CRE1 (Cytokinin Response 1), A-ARR (Type-A Arabidopsis Response Regulator), B-ARR (Type-B Arabidopsis Response Regulator), AUX1 (Auxin Resistant 1), ARF (Auxin Response Factor), AUX/IAA (Auxin/Indole-3-acetic acid), GH3 (Gretchen Hagen 3), SAUR (Small Auxin Up RNA), GA2ox (Gibberellin 2-oxidase), GA20ox (Gibberellin 20-oxidase), AOS (Allene oxide synthase), AOC (Allene oxide cyclase), OPR (Oxophytodienoate Reductase), JMT (JA carboxy l Methyltransferase), COI1 (Coronatine Insensitive 1), JAZ (Jasmonate ZIM-domain), MYC2 (Myelocytomatosis 2), D27 (DWARF27), SMAX (Suppressor of MAX2), PAL (Phenylalanine Ammonia-Lyase), ICS (Isochorismate Synthase), NPR1 (Non-expressor of Pathogenesis-related Genes1), TGA (TGACG Sequence-specific Binding), PR-1 (Pathogenesis-related), MCSU (Molybdenium Cofactor Sulfurase), PP2C (Protein Phosphatase 2C), and SnRK (Sucrose Non-fermenting-related Protein Kinase 2) were highly correlated with hormone concentrations, indicating that bulbil initiation is coordinately controlled by multiple phytohormones. Notably, eight TFs (transcription factors) that regulate AM initiation have been identified as pivotal regulators of bulbil formation. Among these, WUS (WUSCHEL), CLV (CLAVATA), ATH1 (Arabidopsis Thaliana Homeobox Gene 1), and RAX (Regulator of Axillary meristems) have been observed to exhibit elevated expression levels. Conversely, LEAFY demonstrated contrasting expression patterns. The intricate expression profiles of these TFs are closely associated with the upregulated expression of KNOX(KNOTTED-like homeobox), suggesting a intricate regulatory network underlying the complex process of bulbil initiation. This study offers a profound understanding of the bulbil initiation process and could potentially aid in refining molecular breeding techniques specific to P. ternata. Full article

Illicium difengpi (Schisandraceae), which is an endemic, medicinal, and endangered species found in small and isolated populations that inhabit karst mountain areas, has evolved strategies to adapt to arid environments and is thus an excellent material for exploring the mechanisms of tolerance to severe drought. In experiment I, I. difengpi plants were subjected to three soil watering treatments (CK, well-watered treatment at 50% of the dry soil weight for 18 days; DS, drought stress treatment at 10% of the dry soil weight for 18 days; DS-R, drought-rehydration treatment at 10% of the dry soil weight for 15 days followed by rewatering to 50% of the dry soil weight for another 3 days). The effects of the drought and rehydration treatments on leaf succulence, phytohormones, and phytohormonal signal transduction in I. difengpi plants were investigated. In experiment II, exogenous abscisic acid (ABA, 60 mg L⁻¹) and zeatin riboside (ZR, 60 mg L⁻¹) were sprayed onto DS-treated plants to verify the roles of exogenous phytohormones in alleviating drought injury. Leaf succulence showed marked changes in response to the DS and DS-R treatments. The relative concentrations of ABA, methyl jasmonate (MeJA), salicylic acid glucoside (SAG), and cis-zeatin riboside (cZR) were highly correlated with relative leaf succulence. The leaf succulence of drought-treated I. difengpi plants recovered to that observed with the CK treatment after exogenous application of ABA or ZR. Differentially expressed genes involved in biosynthesis and signal transduction of phytohormones (ABA and JA) in response to drought stress were identified by transcriptomic profiling. The current study suggested that the phytohormones ABA, JA, and ZR may play important roles in the response to severe drought and provides a preliminary understanding of the physiological mechanisms involved in phytohormonal regulation in I. difengpi, an endemic, medicinal, and highly drought-tolerant plant found in extremely small populations in the karst region of South China. Full article

Sorghum is one of the most important foods, fodder, and technical crops grown in the world. Global climate change and environmental pollution with toxic industrial and agricultural waste are the most unfavorable environmental factors affecting the growth and development of sorghum, which leads to a decrease in product quality. The development of new environmentally friendly plant growth regulators to improve growth and increase the productivity of sorghum is an urgent task of modern agriculture. Currently, considerable attention is paid to the development of new environmentally friendly plant growth regulators based on 6-methyl-2-mercapto-4-hydroxypyrimidine sodium and potassium salts (Methyur and Kamethur) and N-oxide-2,6-dimethylpyridine (Ivin). Thanks to the use of plant growth regulators Methyur, Kamethur, and Ivin, it is possible to increase the productivity of agricultural crops and their adaptive properties to stress factors of abiotic nature. This work examines the use of plant growth regulators Methyur, Kamethur, and Ivin to increase the productivity of sorghum. Field experiments were carried out on grain sorghum (Sorghum bicolor L.) cv. Yarona and sweet sorghum (Sorghum saccharatum L.) cv. Favorite. Seeds sterilized with 1% KMnO₄ solution were treated either with distilled water (control sample) or with solutions of any plant growth regulators Methyur, Kamethur, or Ivin, applied at a concentration of 10⁻⁷ M for 24 h (experimental sample). Each control and experimental sample contained 50 plant seeds; the experiments were carried out in triplicate. Then the soaked seeds were planted in the soil. Yield indicators such as panicle length (in cm) and fresh weight of grain (in grams), determined in experimental samples of sorghum plants, were calculated as % in relation to similar indicators determined in control samples of sorghum plants. It was shown that the yield indicators of sorghum plants grown for 4 months in the field, treated with Methyur, Kamethur, and Ivin at a concentration of 10⁻⁷ M exceeded those of control plants. Panicle length (in %) of experimental grain sorghum (Sorghum bicolor (L.) Moench) cv. Yarona increased by 7%—in plants treated with Kamethur, 20%—in plants treated with Methyur, and 17%—in plants treated with Ivin, compared to the control. Panicle length (in %) of experimental sweet sorghum (Sorghum saccharatum (L.) Moench) cv. Favorite increased by 36%—in plants treated with Kamethur, 37%—in plants treated with Methyur, and by 25%—in plants treated with Ivin, compared to the control. Grain fresh weight (in %) of experimental grain sorghum (Sorghum bicolor (L.) Moench) cv. Yarona increased by 22%—in plants treated with Kamethur, 26%—in plants treated with Methyur, and 13%—in plants treated with Ivin, compared to the control. Grain fresh weight (in %) of experimental sweet sorghum (Sorghum saccharatum (L.) Moench) cv. Favorite increased by 24%—in plants treated with Kamethur, 38%—in plants treated with Methyur, and 35%—in plants treated with Ivin, compared to the control. Based on the results obtained, a conclusion was made about the high growth-stimulating effect of plant growth regulators, similar to the phytohormones auxins and cytokinin, and the dependence of their effect on their composition. It is proposed to use new environmentally friendly plant growth regulators Methyur, Kamethur, and Ivin to improve growth and increase the productivity of sorghum while reducing the use of environmentally toxic agrochemicals for plant protection and improving the environmental condition of the entire agricultural system. Full article

Centella asiatica is well known for its miraculous therapeutic properties in various systems of traditional medicine across the world. However, significant variation in its pharmacological activities has been reported due to the unavailability of quality raw material and non-standardized formulations. A number of research papers have been published on the collection of C. asiatica plants from different regions for the identification of a suitable agroclimate with elite germplasms. Efforts have been made to standardize production and post-harvest practices for the availability of quality raw material with a high centelloside content. The ecological niche modeling approach revealed that the Indian subcontinent has high climatic suitability for the production of C. asiatica, and genotypes with a high content of centelloside were predominantly found in the Western Ghats, North East, Eastern Himalaya and Western Himalaya in India. Open cultivation of C. asiatica is more suitable in these agroclimatic zones in India. Cultivation under shade is also suitable in the plains of Central India. Hydroponic and tissue culture of C. asiatica has also been successfully established for the enhanced production of centelloside using supplements and elicitors such as sucrose, auxins, cytokinins, kinetin, methyl jasmonate, etc. Freeze drying has been identified as the most efficient post-harvest method for the high pharmacological activities of C. asiatica extracts. Full article

Plant trichomes formed by specialized epidermal cells play a role in protecting plants from biotic and abiotic stresses and can also influence the economic and ornamental value of plant products. Therefore, further studies on the molecular mechanisms of plant trichome growth and development are important for understanding trichome formation and agricultural production. SET Domain Group 26 (SDG26) is a histone lysine methyltransferase. Currently, the molecular mechanism by which SDG26 regulates the growth and development of Arabidopsis leaf trichomes is still unclear. We found that the mutant of Arabidopsis (sdg26) possessed more trichomes on its rosette leaves compared to the wild type (Col-0), and the trichome density per unit area of sdg26 is significantly higher than that of Col-0. The content of cytokinins and jasmonic acid was higher in sdg26 than in Col-0, while the content of salicylic acid was lower in sdg26 than in Col-0, which is conducive to trichome growth. By measuring the expression levels of trichome-related genes, we found that the expression of genes that positively regulate trichome growth and development were up-regulated, while the negatively regulated genes were down-regulated in sdg26. Through chromatin immunoprecipitation sequencing (ChIP-seq) analysis, we found that SDG26 can directly regulate the expression of genes related to trichome growth and development such as ZFP1, ZFP5, ZFP6, GL3, MYB23, MYC1, TT8, GL1, GIS2, IPT1, IPT3, and IPT5 by increasing the accumulation of H3K27me3 on these genes, which further affects the growth and development of trichomes. This study reveals the mechanism by which SDG26 affects the growth and development of trichomes through histone methylation. The current study provides a theoretical basis for studying the molecular mechanism of histone methylation in regulating leaf trichome growth and development and perhaps guiding the development of new crop varieties. Full article

The SHPRH (SNF2, histone linker, PHD, RING, helicase) subfamily belonging to ATP-dependent chromatin remodeling factor is the effective tumor-suppressor, which can polyubiquitinate PCNA (proliferating cell nuclear antigen) and participate in post-replication repair in human. However, little is known about the functions of SHPRH proteins in plants. In this study, we identified a novel SHPRH member BrCHR39 and obtained BrCHR39-silenced transgenic Brassica rapa. In contrast to wild-type plants, transgenic Brassica plants exhibited a released apical dominance phenotype with semi-dwarfism and multiple lateral branches. Furthermore, a global alteration of DNA methylation in the main stem and bud appeared after silencing of BrCHR39. Based on the GO (gene ontology) functional annotation and KEGG (Kyoto encyclopedia of genes and genomes) pathway analysis, the plant hormone signal transduction pathway was clearly enriched. In particular, we found a significant increase in the methylation level of auxin-related genes in the stem, whereas auxin- and cytokinin-related genes were hypomethylated in the bud of transgenic plants. In addition, further qRT-PCR (quantitative real-time PCR) analysis revealed that DNA methylation level always had an opposite trend with gene expression level. Considered together, our findings indicated that suppression of BrCHR39 expression triggered the methylation divergence of hormone-related genes and subsequently affected transcription levels to regulate the apical dominance in Brassica rapa. Full article

Cytokinins, classical phytohormones, affect all stages of plant ontogenesis, but their application in agriculture is limited because of the lack of appropriate ligands, including those specific for individual cytokinin receptors. In this work, a series of chiral N⁶-benzyladenine derivatives were studied as potential cytokinins or anticytokinins. All compounds contained a methyl group at the α-carbon atom of the benzyl moiety, making them R- or S-enantiomers. Four pairs of chiral nucleobases and corresponding ribonucleosides containing various substituents at the C2 position of adenine heterocycle were synthesized. A nucleophilic substitution reaction by secondary optically active amines was used. A strong influence of the chirality of studied compounds on their interaction with individual cytokinin receptors of Arabidopsis thaliana was uncovered in in vivo and in vitro assays. The AHK2 and CRE1/AHK4 receptors were shown to have low affinity for the studied S-nucleobases while the AHK3 receptor exhibited significant affinity for most of them. Thereby, three synthetic AHK3-specific cytokinins were discovered: N⁶-((S)-α-methylbenzyl)adenine (S-MBA), 2-fluoro,N⁶-((S)-α-methylbenzyl)adenine (S-FMBA) and 2-chloro,N⁶-((S)-α-methylbenzyl)adenine (S-CMBA). Interaction patterns between individual receptors and specific enantiomers were rationalized by structure analysis and molecular docking. Two other S-enantiomers (N⁶-((S)-α-methylbenzyl)adenosine, 2-amino,N⁶-((S)-α-methylbenzyl)adenosine) were found to exhibit receptor-specific and chirality-dependent anticytokinin properties. Full article