The GhEB1C gene mediates resistance of cotton to Verticillium wilt.

MAIN CONCLUSION: The GhEB1C gene of the EB1 protein family functions as microtubule end-binding protein and may be involved in the regulation of microtubule-related pathways to enhance resistance to Verticillium wilt. The expression of GhEB1C is induced by SA, also contributing to Verticillium wilt resistance. Cotton, as a crucial cash and oil crop, faces a significant threat from Verticillium wilt, a soil-borne disease induced by Verticillium dahliae, severely impacting cotton growth and development. Investigating genes associated with resistance to Verticillium wilt is paramount. We identified and performed a phylogenetic analysis on members of the EB1 family associated with Verticillium wilt in this work. GhEB1C was discovered by transcriptome screening and was studied for its function in cotton defense against V. dahliae. The RT-qPCR analysis revealed significant expression of the GhEB1C gene in cotton leaves. Subsequent localization analysis using transient expression demonstrated cytoplasmic localization of GhEB1C. VIGS experiments indicated that silencing of the GhEB1C gene significantly increased susceptibility of cotton to V. dahliae. Comparative RNA-seq analysis showed that GhEB1C silenced plants exhibited altered microtubule-associated protein pathways and flavonogen-associated pathways, suggesting a role for GhEB1C in defense mechanisms. Overexpression of tobacco resulted in enhanced resistance to V. dahliae as compared to wild-type plants. Furthermore, our investigation into the relationship between the GhEB1C gene and plant disease resistance hormones salicylic axid (SA) and jasmonic acid (JA) revealed the involvement of GhEB1C in the regulation of the SA pathway. In conclusion, our findings demonstrate that GhEB1C plays a crucial role in conferring immunity to cotton against Verticillium wilt, providing valuable insights for further research on plant adaptability to pathogen invasion.

Infection mechanism of Botryosphaeria dothidea and the disease resistance strategies of Chinese hickory (Carya cathayensis).

Botryosphaeria dothidea is the main fungal pathogen responsible for causing Chinese hickory (Carya cathayensis) dry rot disease, posing a serious threat to the Chinese hickory industry. Understanding the molecular basis of B. dothidea infection and the host's resistance mechanisms is crucial for controlling and managing the ecological impact of Chinese hickory dry rot disease. This study utilized ultrastructural observations to reveal the process of B. dothidea infection and colonization in Chinese hickory, and investigated the impact of B. dothidea infection on Chinese hickory biochemical indicators and plant hormone levels. Through high-throughput transcriptome sequencing, the gene expression profiles associated with different stages of B. dothidea infection in Chinese hickory and their corresponding defense responses were described. Additionally, a series of key genes closely related to non-structural carbohydrate metabolism, hormone metabolism, and plant-pathogen interactions during B. dothidea infection in Chinese hickory were identified, including genes encoding DUF, Myb_DNA-binding, and ABC transporter proteins. These findings provide important insights into elucidating the pathogenic mechanisms of B. dothidea and the resistance genes in Chinese hickory.

Imaging the spatial distribution of structurally diverse plant hormones: A comprehensive review.

Plant hormones are essential and structurally diverse molecules that regulate various aspects of plant growth, development, and stress responses. However, the precise analysis of plant hormones in complex biological samples poses a challenge due to their low concentrations, dynamic levels, and intricate spatial distribution. Moreover, the complexity and interconnectedness of hormone signaling networks make it difficult to simultaneously trace multiple hormone distributions. In this review, we provide an overview of the currently recognized small-molecule plant hormones, signal peptide hormones, and plant growth regulators, along with the analytical methods employed for their analysis. We delve into the latest advancements in mass spectrometry imaging and in situ fluorescence techniques, which enable the examination of the spatial distribution of plant hormones. The advantages and disadvantages of these imaging techniques are further discussed. Finally, we propose potential avenues for future research in this field to further enhance our understanding of plant hormone biology.

Moonlighting Crypto-Enzymes and Domains as Ancient and Versatile Signaling Devices.

Increasing numbers of reports have revealed novel catalytically active cryptic guanylate cyclases (GCs) and adenylate cyclases (ACs) operating within complex proteins in prokaryotes and eukaryotes. Here we review the structural and functional aspects of some of these cyclases and provide examples that illustrate their roles in the regulation of the intramolecular functions of complex proteins, such as the phytosulfokine receptor (PSKR), and reassess their contribution to signal generation and tuning. Another multidomain protein, Arabidopsis thaliana K+ uptake permease (AtKUP5), also harbors multiple catalytically active sites including an N-terminal AC and C-terminal phosphodiesterase (PDE) with an abscisic acid-binding site. We argue that this architecture may enable the fine-tuning and/or sensing of K+ flux and integrate hormone responses to cAMP homeostasis. We also discuss how searches with motifs based on conserved amino acids in catalytic centers led to the discovery of GCs and ACs and propose how this approach can be applied to discover hitherto masked active sites in bacterial, fungal, and animal proteomes. Finally, we show that motif searches are a promising approach to discover ancient biological functions such as hormone or gas binding.

How Do Plant Growth-Promoting Bacteria Use Plant Hormones to Regulate Stress Reactions?

Phytohormones play a crucial role in regulating growth, productivity, and development while also aiding in the response to diverse environmental changes, encompassing both biotic and abiotic factors. Phytohormone levels in soil and plant tissues are influenced by specific soil bacteria, leading to direct effects on plant growth, development, and stress tolerance. Specific plant growth-promoting bacteria can either synthesize or degrade specific plant phytohormones. Moreover, a wide range of volatile organic compounds synthesized by plant growth-promoting bacteria have been found to influence the expression of phytohormones. Bacteria-plant interactions become more significant under conditions of abiotic stress such as saline soils, drought, and heavy metal pollution. Phytohormones function in a synergistic or antagonistic manner rather than in isolation. The study of plant growth-promoting bacteria involves a range of approaches, such as identifying singular substances or hormones, comparing mutant and non-mutant bacterial strains, screening for individual gene presence, and utilizing omics approaches for analysis. Each approach uncovers the concealed aspects concerning the effects of plant growth-promoting bacteria on plants. Publications that prioritize the comprehensive examination of the private aspects of PGPB and cultivated plant interactions are of utmost significance and crucial for advancing the practical application of microbial biofertilizers. This review explores the potential of PGPB-plant interactions in promoting sustainable agriculture. We summarize the interactions, focusing on the mechanisms through which plant growth-promoting bacteria have a beneficial effect on plant growth and development via phytohormones, with particular emphasis on detecting the synthesis of phytohormones by plant growth-promoting bacteria.

Expression Pattern and Functional Analysis of MebHLH149 Gene in Response to Cassava Bacterial Blight.

The significant reduction in cassava (Manihot esculenta Crantz) yields attributed to cassava bacterial blight (CBB) constitutes an urgent matter demanding prompt attention. The current study centered on the MebHLH149 transcription factor, which is acknowledged to be reactive to CBB and exhibits augmented expression levels, as indicated by laboratory transcriptome data. Our exploration, encompassing Xanthomonas phaseoli pv. manihotis strain CHN01 (Xpm CHN01) and hormone stress, disclosed that the MebHLH149 gene interacts with the pathogen at the early stage of infection. Furthermore, the MebHLH149 gene has been discovered to be responsive to the plant hormones abscisic acid (ABA), methyl jasmonate (MeJA), and salicylic acid (SA), intimating a potential role in the signaling pathways mediated by these hormones. An analysis of the protein's subcellular localization suggested that MebHLH149 is predominantly located within the nucleus. Through virus-induced gene silencing (VIGS) in cassava, we discovered that MebHLH149-silenced plants manifested higher disease susceptibility, less ROS accumulation, and significantly larger leaf spot areas compared to control plants. The proteins MePRE5 and MePRE6, which are predicted to interact with MebHLH149, demonstrated complementary downregulation and upregulation patterns in response to silencing and overexpression of the MebHLH149 gene. This implies a potential interaction between MebHLH149 and these proteins. Both MePRE5 and MePRE6 genes are involved in the initial immune response to CBB. Notably, MebHLH149 was identified as a protein that physically interacts with MePRE5 and MePRE6. Based on these findings, it is hypothesized that the MebHLH149 gene likely functions as a positive regulator in the defense mechanisms of cassava against CBB.

The maize ZmCPK39-ZmKnox2 module regulates plant height.

Plant height is an important agronomic trait that affects high-density tolerance and lodging resistance. However, the regulators and their underlying molecular mechanisms controlling plant height in maize remain understudied. Here, we report that knockout mutants of the calcium-dependent protein kinase gene ZmCPK39 (ZmCPK39-KO) exhibit dramatically reduced plant height, characterized by shorter internodes and a slight decrease in node numbers. Furthermore, we identified a ZmCPK39-interacting protein, the knotted-related homeobox (ZmKnox2), and observed that plant height was also significantly reduced in a mutator transposon-inserted mutant of ZmKnox2 (ZmKnox2-Mu). Combined analysis of transcriptomic and metabonomic data indicates that multiple phytohormone signaling and photosynthesis pathways are disrupted in both ZmCPK39-KO and ZmKnox2-Mu mutants. Taken together, these results provide new insights into the function of ZmCPK39 and identify potential targets for breeding lodging-resistant and high-density tolerant maize cultivars. Supplementary Information: The online version contains supplementary material available at 10.1007/s42994-024-00150-y.

Mechanisms by Which Exogenous Substances Enhance Plant Salt Tolerance through the Modulation of Ion Membrane Transport and Reactive Oxygen Species Metabolism.

Soil salinization is one of the major abiotic stresses affecting plant growth and development. Plant salt tolerance is controlled by complex metabolic pathways. Exploring effective methods and mechanisms to improve crop salt tolerance has been a key aspect of research on the utilization of saline soil. Exogenous substances, such as plant hormones and signal transduction substances, can regulate ion transmembrane transport and eliminate reactive oxygen species (ROS) to reduce salt stress damage by activating various metabolic processes. In this review, we summarize the mechanisms by which exogenous substances regulate ion transmembrane transport and ROS metabolism to improve plant salt tolerance. The molecular and physiological relationships among exogenous substances in maintaining the ion balance and enhancing ROS clearance are examined, and trends and research directions for the application of exogenous substances for improving plant salt tolerance are proposed.

Exogenous Substances Used to Relieve Plants from Drought Stress and Their Associated Underlying Mechanisms.

Drought stress (DS) is one of the abiotic stresses that plants encounter commonly in nature, which affects their life, reduces agricultural output, and prevents crops from growing in certain areas. To enhance plant tolerance against DS, abundant exogenous substances (ESs) have been attempted and proven to be effective in helping plants relieve DS. Understanding the effect of each ES on alleviation of plant DS and mechanisms involved in the DS relieving process has become a research focus and hotspot that has drawn much attention in the field of botany, agronomy, and ecology. With an extensive and comprehensive review and summary of hundred publications, this paper groups various ESs based on their individual effects on alleviating plant/crop DS with details of the underlying mechanisms involved in the DS-relieving process of: (1) synthesizing more osmotic adjustment substances; (2) improving antioxidant pathways; (3) promoting photosynthesis; (4) improving plant nutritional status; and (5) regulating phytohormones. Moreover, a detailed discussion and perspective are given in terms of how to meet the challenges imposed by erratic and severe droughts in the agrosystem through using promising and effective ESs in the right way and at the right time.

Exogenous melatonin promoted seed hypocotyl germination of Paeonia ostia 'Fengdan' characterized by regulating hormones and starches.

Background: Seed hypocotyl germination signifies the initiation of the life cycle for plants and represents a critical stage that heavily influences subsequent plant growth and development. While previous studies have established the melatonin (MEL; N-acetyl-5-methoxytrytamine) effect to stimulate seed germination of some plants, its specific role in peony germination and underlying physiological mechanism have yet to be determined. This study aims to evaluate the MEL effect for the hypocotyl germination of peony seeds, further ascertain its physiological regulation factors. Methods: In this work, seeds of Paeonia ostia 'Fengdan' were soaked into MEL solution at concentrations of 50, 100, 200, and 400 µM for 48 h and then germinated in darkness in incubators. Seeds immersed in distilled water without MEL for the same time were served as the control group. Results: At concentrations of 100 and 200 µM, MEL treatments improved the rooting rate of peony seeds, while 400 µM inhibited the process. During seed germination, the 100 and 200 µM MEL treatments significantly reduced the starch concentration, and α-amylase was the primary amylase involved in the action of melatonin. Additionally, compared to the control group, 100 µM MEL treatment significantly increased the GA3 concentration and radicle thickness of seeds, but decreased ABA concentration. The promotion effect of 200 µM MEL pretreatment on GA1 and GA7 was the most pronounced, while GA4 concentration was most significantly impacted by 50 µM and 100 µM MEL. Conclusion: Correlation analysis established that 100 µM MEL pretreatment most effectively improved the rooting rate characterized by increasing α-amylase activity to facilitate starch decomposition, boosting GA3 levels, inhibiting ABA production to increase the relative ratio of GA3 to ABA. Moreover, MEL increased radicle thickness of peony seeds correlating with promoting starch decomposition and enhancing the synthesis of GA1 and GA7.

Transcriptomic analyses provide molecular insight into the cold stress response of cold-tolerant alfalfa.

BACKGROUND: Daye No.3 is a novel cultivar of alfalfa (Medicago sativa L.) that is well suited for cultivation in high-altitude regions such as the Qinghai‒Tibet Plateau owing to its high yield and notable cold resistance. However, the limited availability of transcriptomic information has hindered our investigation into the potential mechanisms of cold tolerance in this cultivar. Consequently, we conducted de novo transcriptome assembly to overcome this limitation. Subsequently, we compared the patterns of gene expression in Daye No. 3 during cold acclimatization and exposure to cold stress at various time points. RESULTS: A total of 15 alfalfa samples were included in the transcriptome assembly, resulting in 141.97 Gb of clean bases. A total of 441 DEGs were induced by cold acclimation, while 4525, 5016, and 8056 DEGs were identified at 12 h, 24 h, and 36 h after prolonged cold stress at 4 °C, respectively. The consistency between the RT‒qPCR and transcriptome data confirmed the accuracy and reliability of the transcriptomic data. KEGG enrichment analysis revealed that many genes related to photosynthesis were enriched under cold stress. STEM analysis demonstrated that genes involved in nitrogen metabolism and the TCA cycle were consistently upregulated under cold stress, while genes associated with photosynthesis, particularly antenna protein genes, were downregulated. PPI network analysis revealed that ubiquitination-related ribosomal proteins act as hub genes in response to cold stress. Additionally, the plant hormone signaling pathway was activated under cold stress, suggesting its vital role in the cold stress response of alfalfa. CONCLUSIONS: Ubiquitination-related ribosomal proteins induced by cold acclimation play a crucial role in early cold signal transduction. As hub genes, these ubiquitination-related ribosomal proteins regulate a multitude of downstream genes in response to cold stress. The upregulation of genes related to nitrogen metabolism and the TCA cycle and the activation of the plant hormone signaling pathway contribute to the enhanced cold tolerance of alfalfa.

Integrating Physiology, Cytology, and Transcriptome to Reveal the Leaf Variegation Mechanism in Phalaenopsis Chia E Yenlin Variegata Leaves.

Phalaenopsis orchids, with their unique appearance and extended flowering period, are among the most commercially valuable Orchidaceae worldwide. Particularly, the variegation in leaf color of Phalaenopsis significantly enhances the ornamental and economic value and knowledge of the molecular mechanism of leaf-color variegation in Phalaenopsis is lacking. In this study, an integrative analysis of the physiology, cytology, and transcriptome profiles was performed on Phalaenopsis Chia E Yenlin Variegata leaves between the green region (GR) and yellow region (YR) within the same leaf. The total chlorophyll and carotenoid contents in the YR exhibited a marked decrease of 72.18% and 90.21%, respectively, relative to the GR. Examination of the ultrastructure showed that the chloroplasts of the YR were fewer and smaller and exhibited indistinct stromal lamellae, ruptured thylakoids, and irregularly arranged plastoglobuli. The transcriptome sequencing between the GR and YR led to a total of 3793 differentially expressed genes, consisting of 1769 upregulated genes and 2024 downregulated genes. Among these, the chlorophyll-biosynthesis-related genes HEMA, CHLH, CRD, and CAO showed downregulation, while the chlorophyll-degradation-related gene SGR had an upregulated expression in the YR. Plant-hormone-related genes and transcription factors MYBs (37), NACs (21), ERFs (20), bHLH (13), and GLK (2), with a significant difference, were also analyzed. Furthermore, qRT-PCR experiments validated the above results. The present work establishes a genetic foundation for future studies of leaf-pigment mutations and may help to improve the economic and breeding values of Phalaenopsis.

Strigolactones Negatively Regulate Tobacco Mosaic Virus Resistance in Nicotiana benthamiana.

Strigolactones (SLs) are plant hormones that regulate diverse developmental processes and environmental responses in plants. It has been discovered that SLs play an important role in regulating plant immune resistance to pathogens but there are currently no reports on their role in the interaction between Nicotiana benthamiana and the tobacco mosaic virus (TMV). In this study, the exogenous application of SLs weakened the resistance of N. benthamiana to TMV, promoting TMV infection, whereas the exogenous application of Tis108, a SL inhibitor, resulted in the opposite effect. Virus-induced gene silencing (VIGS) inhibition of two key SL synthesis enzyme genes, NtCCD7 and NtCCD8, enhanced the resistance of N. benthamiana to TMV. Additionally, we conducted a screening of N. benthamiana related to TMV infection. TMV-infected plants treated with SLs were compared to the control by using RNA-seq. The KEGG enrichment analysis and weighted gene co-expression network analysis (WGCNA) of differentially expressed genes (DEGs) suggested that plant hormone signaling transduction may play a significant role in the SL-TMV-N. benthamiana interactions. This study reveals new functions of SLs in regulating plant immunity and provides a reference for controlling TMV diseases in production.

Light at the end of the tunnel: integrating signaling pathways in the coordination of lateral root development.

Root system architecture (RSA) encompasses a range of physical root attributes, including the lateral roots (LRs), root hairs and adventitious roots, in addition to the primary or main root. This overall structure is a crucial trait for efficient water and mineral capture alongside providing anchorage to the plant in the soil and is vital for plant productivity and fitness. RSA dynamics are dependent upon various environmental cues such as light, soil pH, water, mineral nutrition and the belowground microbiome. Among these factors, light signaling through HY5 significantly influences the flexibility of RSA by controlling different signaling pathways that converge at photoreceptors-mediated signaling, also present in the 'hidden half'. Furthermore, several phytohormones also drive the formation and emergence of LRs and are critical to harmonize intra and extracellular stimuli in this regard. This review endeavors to elucidate the impact of these interactions on RSA, with particular emphasis on LR development and to enhance our understanding of the fundamental mechanisms governing the light-regulation of LR growth and physiology.

Genome-Wide Identification of Seven in Absentia E3 Ubiquitin Ligase Gene Family and Expression Profiles in Response to Different Hormones in Uncaria rhynchophylla.

SINA (Seven in absentia) E3 ubiquitin ligases are a family of RING (really interesting new gene) E3 ubiquitin ligases, and they play a crucial role in regulating plant growth and development, hormone response, and abiotic and biotic stress. However, there is little research on the SINA gene family in U. rhynchophylla. In this study, a total of 10 UrSINA genes were identified from the U. rhynchophylla genome. The results of multiple sequence alignments and chromosomal locations show that 10 UrSINA genes were unevenly located on 22 chromosomes, and each UrSINA protein contained a SINA domain at the N-terminal and RING domains at the C-terminal. Synteny analysis showed that there are no tandem duplication gene pairs and there are four segmental gene pairs in U. rhynchophylla, contributing to the expansion of the gene family. Furthermore, almost all UrSINA genes contained the same gene structure, with three exons and two introns, and there were many cis-acting elements relating to plant hormones, light responses, and biotic and abiotic stress. The results of qRT-PCR show that most UrSINA genes were expressed in stems, with the least expression in roots; meanwhile, most UrSINA genes and key enzyme genes were responsive to ABA and MeJA hormones with overlapping but different expression patterns. Co-expression analysis showed that UrSINA1 might participate in the TIA pathway under ABA treatment, and UrSINA5 and UrSINA6 might participate in the TIA pathway under MeJA treatment. The mining of UrSINA genes in the U. rhynchophylla provided novel information for understanding the SINA gene and its function in plant secondary metabolites, growth, and development.

A delayed response in phytohormone signaling and production contributes to pine susceptibility to Fusarium circinatum.

BACKGROUND: Fusarium circinatum is the causal agent of pine pitch canker disease, which affects Pinus species worldwide, causing significant economic and ecological losses. In Spain, two Pinus species are most affected by the pathogen; Pinus radiata is highly susceptible, while Pinus pinaster has shown moderate resistance. In F. circinatum-Pinus interactions, phytohormones are known to play a crucial role in plant defense. By comparing species with different degrees of susceptibility, we aimed to elucidate the fundamental mechanisms underlying resistance to the pathogen. For this purpose, we used an integrative approach by combining gene expression and metabolomic phytohormone analyses at 5 and 10 days post inoculation. RESULTS: Gene expression and metabolite phytohormone contents suggested that the moderate resistance of P. pinaster to F. circinatum is determined by the induction of phytohormone signaling and hormone rearrangement beginning at 5 dpi, when symptoms are still not visible. Jasmonic acid was the hormone that showed the greatest increase by 5 dpi, together with the active gibberellic acid 4 and the cytokinin dehydrozeatin; there was also an increase in abscisic acid and salicylic acid by 10 dpi. In contrast, P. radiata hormonal changes were delayed until 10 dpi, when symptoms were already visible; however, this increase was not as high as that in P. pinaster. Indeed, in P. radiata, no differences in jasmonic acid or salicylic acid production were found. Gene expression analysis supported the hormonal data, since the activation of genes related to phytohormone synthesis was observed earlier in P. pinaster than in the susceptible P. radiata. CONCLUSIONS: We determine that the moderate resistance of P. pinaster to F. circinatum is in part a result of early and strong activation of plant phytohormone-based defense responses before symptoms become visible. We suggest that jasmonic acid signaling and production are strongly associated with F. circinatum resistance. In contrast, P. radiata susceptibility was attributed to a delayed response to the fungus at the moment when symptoms were visible. Our results contribute to a better understanding of the phytohormone-based defense mechanism involved in the Pinus-F. circinatum interactions and provide insight into the development of new strategies for disease mitigation.

De novo transcriptome profiling reveals the patterns of gene expression in plum fruits with bud mutations.

Bud mutation is a common technique for plant breeding and can provide a large number of breeding materials. Through traditional breeding methods, we obtained a plum plant with bud mutations (named "By") from an original plum variety (named "B"). The ripening period of "By" fruit was longer than that of "B" fruit, and its taste was better. In order to understand the characteristics of these plum varieties, we used transcriptome analysis and compared the gene expression patterns in fruits from the two cultivars. Subsequently, we identified the biological processes regulated by the differentially expressed genes (DEGs). Gene ontology (GO) analysis revealed that these DEGs were highly enriched for "single-organism cellular process" and "transferase activity". KEGG analysis demonstrated that the main pathways affected by the bud mutations were plant hormone signal transduction, starch and sucrose metabolism. The IAA, CKX, ARF, and SnRK2 genes were identified as the key regulators of plant hormone signal transduction. Meanwhile, TPP, the beta-glucosidase (EC3.2.1.21) gene, and UGT72E were identified as candidate DEGs affecting secondary metabolite synthesis. The transcriptome sequencing (RNA-seq) data were also validated using RT-qPCR experiments. The transcriptome analysis demonstrated that plant hormones play a significant role in extending the maturity period of plum fruit, with IAA, CKX, ARF, and SnRK2 serving as the key regulators of this process. Further, TPP, beta-glucosidase (EC3.2.1.21), and UGT72E appeared to mediate the synthesis of various soluble secondary metabolites, contributing to the aroma of plum fruits. The expression of BAG6 was upregulated in "B" as the fruit matured, but it was downregulated in "By". This indicated that "B" may have stronger resistance, especially fungal resistance. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01472-3.

Integrated analysis of miRNAs, transcriptome and phytohormones in the flowering time regulatory network of tea oil camellia.

Camellia oleifera is a crucial cash crop in the southern region of China. Timely flowering is a crucial characteristic for maximizing crop productivity. Nevertheless, the cold temperature and wet weather throughout the fall and winter seasons in South China impact the timing of flowering and the yield produced by C. oleifera. This study examined the miRNAs, transcriptomes, and phytohormones that are part of the flowering time regulatory networks in distinct varieties of C. oleifera (Sep, Oct, and Nov). This study provides evidence that phytohormones significantly impact the timing of flowering in C. oleifera leaves. There is a positive correlation between the accumulation variations of zeatin (cZ), brassinolide (BL), salicylic acid (SA), 1-amino cyclopropane carboxylic acid (ACC), and jasmonic acid (JA) and flowering time. This means that blooming occurs earlier when the quantity of these substances in leaves increases. Abscisic acid (ABA), trans-zeatin-riboside (tZR), dihydrozeatin (dh-Z), and IP (N6-Isopentenyladenine) exhibit contrasting effects. Furthermore, both miR156 and miR172 play a crucial function in regulating flowering time in C. oleifera leaves by modulating the expression of SOC1, primarily through the miR156-SPL and miR172-AP2 pathways. These findings establish a strong basis for future research endeavors focused on examining the molecular network associated with the flowering period of C. oleifera and controlling flowering time management through external treatments. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01473-2.

Transcriptome- and genome-wide systematic identification of expansin gene family and their expression in tuberous root development and stress responses in sweetpotato (Ipomoea batatas).

Introduction: Expansins (EXPs) are essential components of the plant cell wall that function as relaxation factors to directly promote turgor-driven expansion of the cell wall, thereby controlling plant growth and development and diverse environmental stress responses. EXPs genes have been identified and characterized in numerous plant species, but not in sweetpotato. Results and methods: In the present study, a total of 59 EXP genes unevenly distributed across 14 of 15 chromosomes were identified in the sweetpotato genome, and segmental and tandem duplications were found to make a dominant contribution to the diversity of functions of the IbEXP family. Phylogenetic analysis showed that IbEXP members could be clustered into four subfamilies based on the EXPs from Arabidopsis and rice, and the regularity of protein motif, domain, and gene structures was consistent with this subfamily classification. Collinearity analysis between IbEXP genes and related homologous sequences in nine plants provided further phylogenetic insights into the EXP gene family. Cis-element analysis further revealed the potential roles of IbEXP genes in sweetpotato development and stress responses. RNA-seq and qRT-PCR analysis of eight selected IbEXPs genes provided evidence of their specificity in different tissues and showed that their transcripts were variously induced or suppressed under different hormone treatments (abscisic acid, salicylic acid, jasmonic acid, and 1-aminocyclopropane-1-carboxylic acid) and abiotic stresses (low and high temperature). Discussion: These results provide a foundation for further comprehensive investigation of the functions of IbEXP genes and indicate that several members of this family have potential applications as regulators to control plant development and enhance stress resistance in plants.

Overexpression of MtIPT gene enhanced drought tolerance and delayed leaf senescence of creeping bentgrass (Agrostis stolonifera L.).

BACKGROUND: Isopentenyltransferases (IPT) serve as crucial rate-limiting enzyme in cytokinin synthesis, playing a vital role in plant growth, development, and resistance to abiotic stress. RESULTS: Compared to the wild type, transgenic creeping bentgrass exhibited a slower growth rate, heightened drought tolerance, and improved shade tolerance attributed to delayed leaf senescence. Additionally, transgenic plants showed significant increases in antioxidant enzyme levels, chlorophyll content, and soluble sugars. Importantly, this study uncovered that overexpression of the MtIPT gene not only significantly enhanced cytokinin and auxin content but also influenced brassinosteroid level. RNA-seq analysis revealed that differentially expressed genes (DEGs) between transgenic and wild type plants were closely associated with plant hormone signal transduction, steroid biosynthesis, photosynthesis, flavonoid biosynthesis, carotenoid biosynthesis, anthocyanin biosynthesis, oxidation-reduction process, cytokinin metabolism, and wax biosynthesis. And numerous DEGs related to growth, development, and stress tolerance were identified, including cytokinin signal transduction genes (CRE1, B-ARR), antioxidase-related genes (APX2, PEX11, PER1), Photosynthesis-related genes (ATPF1A, PSBQ, PETF), flavonoid synthesis genes (F3H, C12RT1, DFR), wax synthesis gene (MAH1), senescence-associated gene (SAG20), among others. CONCLUSION: These findings suggest that the MtIPT gene acts as a negative regulator of plant growth and development, while also playing a crucial role in the plant's response to abiotic stress.