Search Results (106)

Leaf morphogenesis is governed by a tightly integrated regulatory network centered on auxin, which operates through a sequential axis of synthesis, transport, and signal transduction. This review elucidates how pivotal molecular hubs previously identified in this regulatory network, including biosynthetic enzymes, polar transporters, and auxin response factors, interconnect through dynamic feedback mechanisms to orchestrate leaf initiation, polarity establishment, and the determination of its final size and shape. Notably, recent breakthroughs are transforming the field: the re-evaluation of established pathways like indole-3-acetaldoxime (IAOx), whose direct contribution to auxin pools is under scrutiny, hinting at the existence of undiscovered enzymes or alternative metabolic branches and the paradigm-shifting discovery that cAMP functions as a second messenger produced by Transport Inhibitor Resistant 1/Auxin signaling F-box (TIR1/AFB) receptors, which directly activates Auxin Response Factor (ARF)-mediated transcription. These foundational mechanistic insights provide the critical groundwork for application. Key network nodes—such as PIN-FORMED (PIN) transporters and YUCCA (YUC) flavin-containing monooxygenases—are now validated targets for crop improvement. Consequently, the elucidated network serves as a blueprint for rationally designing crop architecture. Full article

Flowers are key reproductive structures for many plant species. They are essential for seed and fruit production, and their development is tightly regulated by hormonal and genetic networks. The homeodomain transcription factors HAT3 and ATHB4 are known regulators of adaxial identity and hormone response. We demonstrate that flowers of the hat3 athb4 double mutant emerge at wider divergence angles relative to the wild type, a phenotype reflecting modified phyllotaxy and regulated by low auxin conditions. In addition, hat3 athb4 flowers exhibit aberrant trichome patterning on their sepals associated with enhanced sensitivity to cytokinin (CK). Through RNA-seq analysis of hat3 athb4 inflorescences, we identify the misregulation of genes involved in auxin biosynthesis (YUCCAs), auxin transport (PID), and CK metabolism (CKXs) and transport (PUPs). These findings suggest that HAT3 and ATHB4 fine-tune the auxin/CK balance and coordinate critical pattern events during reproductive development, offering new insight into hormone-mediated regulation of floral patterning. Full article

Soil salinization is one of the most severe abiotic stresses that restricts agricultural productivity worldwide. Pomegranate exhibits relative tolerance to salinity, yet the early response mechanisms in roots remain unclear. In this study, the physiological and transcriptional responses of pomegranate roots to salinity stress were systematically investigated. Salinity stress significantly induced the accumulation of total soluble sugar and proline by up to 8% and 67%, and enhanced the activities of superoxide dismutase (68%) and peroxidase (31%), indicating the activation of osmotic adjustment and antioxidant defense systems. A total of 7548 and 7462 genes were differentially expressed under 100 mM and 200 mM NaCl treatments, respectively. Functional annotation highlighted the critical roles of pathways involved in stress response and plant hormone signal transduction. Comprehensive transcriptional reprogramming was observed in the auxin pathway, involving biosynthesis (YUCCA), transport (PIN and AUX1), and signaling components (TIR1, AUX/IAA, ARF, and GH3). Hormone quantification and RT-qPCR validation confirmed the regulatory functions of auxin through sophisticated hormonal crosstalk. These findings revealed the pivotal role of auxin as a central hub in coordinating the early salinity stress response in pomegranate roots and provided crucial insights and candidate gene resources for enhancing salt tolerance in woody fruit species. Full article

Plants have the capacity to form adventitious roots (ARs) from detached aerial organs, a process known as de novo root regeneration (DNRR). In Arabidopsis, wounding signals rapidly induce in leaf explants the expression of genes encoding enzymes of auxin biosynthesis, resulting in elevated auxin levels and facilitating AR formation. Here, we report that DEVELOPMENT-RELATED POLYCOMB TARGET IN THE APEX 4 (DPA4/NGAL3), a well-known regulator in seed size and leaf margin development, and a repressor of CUP-SHAPED COTYLEDON 2 (CUC2), inhibits AR formation in detached leaves. Leaf explants of dpa4-2 and cuc2-1D mutants displayed both elevated CUC2 mRNA levels and increased rooting rates. We observed reduced expression of ULTRAPETALA1 (ULT1), a negative regulator of DNRR, while the auxin biosynthesis genes ASA1, YUC4, and YUC9 were upregulated in both mutants. Through pharmacological inhibition of YUCCA-mediated auxin biogenesis, we obtained evidence that the enhanced AR formation in both mutants is at least partially a result of increased auxin production. Genetic analysis of dpa4-2 cuc2-1D double mutants indicates that similar mechanisms promote DNRR in both mutants. In summary, our study suggests that DPA4 suppresses AR formation likely by repression of CUC2 and activation of ULT1, which, in turn, suppresses endogenous auxin biogenesis and DNRR. Full article

Vegetative propagation through stem cuttings represents the primary mode of reproduction in Rosa species. While numerous studies have reported physiological factors affecting cutting rooting, the genes regulating the formation of adventitious roots in roses have not yet been fully explored and studied. In this study, we demonstrate that Rosa rugosa ‘Feng Hua’ exhibits an indirect rooting pattern, requiring callus formation prior to root primordium differentiation. Phytohormone profiling revealed exceptionally high concentrations of auxin precursors, particularly tryptophan (Trp), in both callus and root tissues. Therefore, we identified and analyzed the members of the YUCCA family, which are the key rate-limiting enzymes in the tryptophan-dependent IAA biosynthesis pathway. A total of 11 RrYUCs family genes were identified, with RT-qPCR analysis showing that RrYUC10 was highly expressed in callus and root tissues. Functional studies confirmed its critical role in adventitious root formation: virus-induced gene silencing (VIGS) of RrYUC10 significantly inhibited AR development, whereas its overexpression enhanced rooting. Our findings have provided a molecular theoretical basis for the rooting of cuttings in roses. Full article

Grafting serves as a crucial propagation technique for superior Camellia oleifera varieties, where rootstock–scion compatibility significantly determines survival and growth performance. To systematically evaluate grafting compatibility in this economically important woody oil crop, we examined 15 rootstock–scion combinations using ‘Xianglin 210’ as the scion, assessing growth traits and conducting physiological assays (enzymatic activities of SOD and POD and levels of ROS and IAA) at multiple timepoints (0–32 days post-grafting). The results demonstrated that Comb. 4 (Xianglin 27 rootstock) exhibited superior compatibility, characterized by systemic antioxidant activation (peaking at 4–8 DPG), rapid auxin accumulation (4 DPG), and efficient sugar allocation. Transcriptome sequencing and WGCNA analysis identified 3781 differentially expressed genes, with notable enrichment in stress response pathways (Hsp70, DnaJ) and auxin biosynthesis (YUCCA), while also revealing key hub genes (FKBP19) associated with graft-healing efficiency. These findings establish that successful grafting in C. oleifera depends on coordinated rapid redox regulation, auxin-mediated cell proliferation, and metabolic reprogramming, with Comb. 4 emerging as the optimal rootstock choice. The identified molecular markers not only advance our understanding of grafting mechanisms in woody plants but also provide valuable targets for future breeding programs aimed at improving grafting success rates in this important oil crop. Full article

Plant hormones are critical regulators of graft union healing, yet the specific role of exogenous naphthylacetic acid (NAA) in graft union healing efficiency and grafted seedling growth remains unexplored. In this study, we investigated the effects of exogenous NAA treatment (40 mg·L⁻¹) on graft union healing and grafted seedling quality in oriental melon scion grafted onto squash rootstock. Our results demonstrated that exogenous NAA application significantly accelerated vascular bundle reconnection, a key indicator of successful graft union formation. The exogenous NAA treatment enhanced indole-3-acetic acid (IAA) biosynthesis by upregulating key enzymes (TDC, PDC, FMO, NIT, and TAA) and gene expression (CmYUCCA10, CmCYP450, CmoCYP450, and CmoTAA1). The exogenous NAA treatment also upregulated critical graft healing-related genes (CmoWIND1, CmoWOX4, CmoCDKB1;2, CmTMO6, CmoTMO6, CmVND7, and CmoVND7). The exogenous NAA-treated seedlings exhibited better growth. These findings reveal the potential molecular and physiological mechanisms by which exogenous NAA promotes graft union healing of melon grafted onto squash. While the results highlight the potential of exogenous NAA as a grafting enhancer under controlled conditions, further field studies are also needed to validate its practical applicability in commercial production. Full article

The growing demand for sustainable materials has led to innovation in the development of natural compound-based solutions for industrial applications. This study introduces composite nanoparticles (NP-CsYBE) synthesized from chitosan (Cs) and saponin-rich yucca extract (YBE), highlighting their application in Pickering emulsions (PE). Characterization via DLS and AFM revealed NP-CsYBE as spherical particles with a hydrodynamic diameter of 230 nm and a ζ-potential of +36.9 mV, showing a non-aggregated morphology. Comparative analyses of emulsions formulated with Cs nanoparticles (Cs-NP) and YBE were conducted to assess the individual contributions of each component. Functional evaluations revealed that PE based on NP-CsYBE exhibited superior stability over time compared to those with Cs-NP or YBE alone. Additionally, the rheological properties of NP-CsYBE PE were influenced by pH: liquid-viscous behavior dominated at pH 4, while at pH 6.5, solid-elastic properties prevailed. Notably, increased temperature enhanced its mechanical properties. This innovative approach provides a framework for applying natural nanoparticles in PE formation, offering potential applications in the pharmaceutical, food, medical, and cosmetic industries, as well as biomaterials for protecting lipophilic substances. By leveraging natural resources, this work advances the understanding of natural nanoparticle-based systems and their role in developing sustainable and functional materials for industrial use. Full article

The initiation and specification of germline cells are crucial for plant reproduction and the continuity of species. In Arabidopsis thaliana, auxin plays a vital role in guiding the transition of somatic cells into germline fate, orchestrating the specification of both male archesporial cells and female megaspore mother cells. This process is regulated through interaction with the transcription factor Sporocyteless/Nozzle, which forms a feedback mechanism that modulates germ cell specialization. Auxin biosynthesis, polar transport, and signal transduction pathways collectively ensure the accurate determination of germ cell fate. Furthermore, the coordination of auxin signaling with epigenetic regulation and miRNA-mediated control fine-tunes the differentiation between germline and somatic cells. This review discusses the mechanisms underlying auxin-guided germ cell specification. It proposes future research directions, including studies on PIN-FORMED-mediated polar transport, the role of the YUCCA family in auxin biosynthesis, and the involvement of the Transport Inhibitors Response 1/Auxn Signaling F-Box-Auxin Response Factor (TIR1/AFB-ARF) signaling pathway in germ cell fate determination. These insights will enhance our understanding of plant reproductive biology and provide new strategies for crop breeding. Full article

The objective of this study was to evaluate the variation in the mineral concentrations of the inflorescences of Yucca filifera (izote), Agave salmiana (maguey), Diphysa americana (cuachepil), and Chamaedorea tepejilote (tepejilote) in samples collected from different communities in Oaxaca, Mexico. For each sample, the concentrations of macro- and microelements were determined via inductively coupled plasma–optical emission spectrometry (ICP-OES). For each species, significant differences (p < 0.05) in mineral contents were detected on the basis of geographic sampling origin, both among and within locations, for all the minerals evaluated except for Na in all the cases, Cu in izote and tepejilote, and Si in maguey. The macro- and microelement patterns range from highest to lowest concentrations were as follows: K > Ca ≥ P > Mg > S > Na and Si > Fe ≥ Zn > Mn > Cu > Mo. High values were recorded in tepejilote, whereas low values were observed in cuachepil, maguey pulquero, and izote. The average values between species ranged from 199.1 to 3650.3, 243.6 to 3383.7, 354.8 to 941.7, 164.5 to 1281, 76.2 to 1142.9, 1.3 to 44.7, 4.27 to 201, 2.41 to 13.67, 3.08 to 9.23, 0.81 to 13.65, and 0.52 to 3.09 mg 100 g⁻¹ dw in K, Ca, P, Mg, S, Na, Si, Fe, Zn, Mn, and Cu, respectively, indicating a nutritional source in the regions where they are distributed. Full article

Mexican yuca (Yucca decipiens Trel.) is native to the semi-desert region of north-central Mexico. Based on its medicinal uses, the flour produced from its leaves and stems was evaluated to determine new food uses. The flour was characterized based on granulometry, rheology, texture and functional properties, which were analyzed with the RStudio software. The results indicate that the Water Absorption Index (WAI) of yuca flour (0.11 mL g−¹) is similar to that of wheat flour (0.56 mL g−¹). However, the Fat Absorption Index (FAI) of yuca flour (0.40 mL g−¹) is significantly lower than that of Saltillo Pinto bean flour (1.55 mL g−¹). This suggests that yuca exhibits hydrophilic behavior comparable to that of wheat flour and requires less oil in potential formulations. The expansion capacity of yuca flour is similar to that of wheat flour, demonstrating a gluten-like behavior ideal for food applications that require this structural component. The flour also exhibited notable foaming properties, high stability and low fat content, highlighting its food potential. Fermentation matched the parameters of the Cereal & Grains Association’s physicochemical test methods 56–60; consequently, yuca flours are classified as the same as those produced from soft, weak wheat, supporting their use for fermentation processes. Internal friction values (0.85–0.92) suggest limited flow; however, its high density shows fine granulometry that facilitates the bagging, handling and storage of the flour, complying with the Mexican standards. Full article

Astragalus extract plays a dual role in gut microbiome regulation and ammonia (NH₃) emission mitigation in laying hens. This study explored its effects through feeding experiments, with a focus on gut microbial metabolic pathways and NH₃ reduction mechanisms. To achieve this, both in vitro fermentation experiments and in vivo feeding trials were conducted. In the in vitro study, cecal contents from laying hens were incubated with different concentrations of AE and Yucca extract (YE) to evaluate NH₃ production, while in the feeding trial, 58-week-old Lohmann Pink laying hens were allocated into three groups (control, 0.1% YE, and 0.1% AE) and housed in controlled-environment respiration chambers for 21 days. Measurements included NH₃ emissions, serum biochemical indices, immune parameters, gut physicochemical properties, and 16S rRNA-based microbiota analysis. Results showed that Astragalus extract reduced NH₃ emissions by 29.3%, achieved by lowering urease and uricase activities and promoting the conversion of ammonium nitrogen to nitrate nitrogen. Additionally, it significantly enhanced gut immune function by increasing intestinal immunoglobulin levels. Microbial community analysis revealed an increased relative abundance of Bacteroides, Muribaculaceae, and Faecalibacterium, which are negatively correlated with NH₃ emissions. These microbial shifts improved ammonium nitrogen utilization via the upregulation of CTP synthase and GMP synthase activities, contributing to higher NH₃ reduction efficiency. This study highlights Astragalus extract as a cost-effective and sustainable strategy to regulate gut microbiota, optimize nitrogen metabolism, and mitigate NH₃ emissions in laying hens. Full article

In the diet of calves, the search for additives that aid in their development is essential due to the impact that these can generate throughout their lives, resulting in a relationship with their longevity and the maintenance of the herd. Yuca schidigera has been used in ruminant diets, impacting health and performance; however, there are few reports on its intake by dairy cattle in the rearing phase. Therefore, this study’s objective was to evaluate whether adding Yucca schidigera to the diet of calves in the rearing phase can benefit health, productive performance, and feed efficiency. The study was conducted over 60 days, with 24 calves divided into two groups: G1 had no added Yucca schidigera and G2 had 188 mg of Yucca schidigera added per kg of dry matter intake. Data and samples were collected at 30-day intervals. No treatment effect was observed in body weight, weight gain, daily weight gain, or feed intake (p > 0.05); however, the calves in G2 showed 26.3% lower feed efficiency than those in G1. Using the concentrate consumption of the calves, the amount of Yucca schidigera ingested was calculated, i.e., 555 mg/calf/day. The total leukocyte count was significantly lower in the calves in G2 compared to G1 on the 60th day. No effect from the treatment or treatment × day interaction was observed for the hematologic variables: erythrocytes, hemoglobin, hematocrit, lymphocytes, granulocytes, monocytes, and platelets. The activities of the enzyme’s gamma glutamyl transferase and aspartate aminotransferase were higher in the animals in group G2. There was no effect from the treatment on albumin, globulin, total protein, C-reactive protein, glucose, cholesterol, urea, or amylase. There was a treatment × day interaction for levels of reactive oxygen species, lipid peroxidation, and glutathione S-transferase, which were higher in the blood of calves in group G2 compared to the control. The activity of myeloperoxidase, superoxide dismutase, and catalase did not differ between groups. Tumor necrosis factor and interleukins (IL-1 and IL-6) in the serum of calves that consumed Yucca schidigera were higher on day 60 compared to the control. A higher concentration of short-chain fatty acids in the ruminal fluid was observed in animals in group G2 compared to G1, primarily due to the higher levels of acetic acid. The amounts of propionate and butyrate were lower in the ruminal fluid of calves in group G2. These results allow us to conclude that the consumption of Yucca schidigera at a dose of 555 mg/animal/day interferes with calves’ metabolism and negatively affects feed efficiency. Full article

Hypocotyl length is closely related to quality in seedlings and is an important component of plant height vital for plant-type breeding in cucumber. However, the underlying molecular mechanisms of hypocotyl elongation are poorly understood. In this study, the endogenous hormone content of indole acetic acid (IAA) and gibberellin (GA₃) showed an increase in the long hypocotyl Csphyb (phytochrome B) mutant AM274M compared with its wild-type AM274W. An RNA-sequencing analysis identified 1130 differentially expressed genes (DEGs), of which 476 and 654 were up- and downregulated in the mutant AM274M, respectively. A KEGG enrichment analysis exhibited that these DEGs were mainly enriched in the plant hormone signal transduction pathway. The expression levels of the pivotal genes CsGA20ox-2, in the gibberellin biosynthesis pathway, and CsYUCCA8, in the auxin biosynthesis pathway, were notably elevated in the hypocotyl of the mutant AM274M, in contrast to the wild-type AM274W. Additionally, GUS staining and a dual-luciferase reporter assay corroborated that the phytochrome-interacting factors CsPIF3/4 can bind to the E(G)-box motifs present in the promoters of the CsGA20ox-2 and CsYUCCA8 genes, thereby modulating their expression and subsequently influencing hypocotyl elongation. Consequently, this research offers profound insights into the regulation of hypocotyl elongation by auxin and gibberellin in response to light signals and establishes a crucial theoretical groundwork for cultivating robust cucumber seedlings in agricultural practice. Full article

Background: Drought stress has become one of the biggest concerns in threating the growth and yield of carrots (Daucus carota L.). Recent studies have shed light on the physiological and molecular metabolisms in response to drought in the carrot plant; however, tissue-specific responses and regulations are still not fully understood. Methods: To answer this curiosity, this study investigated the interplay among carrot tissues, such as leaves (L); storage roots (SRs); and lateral roots (LRs) under drought conditions. This study revealed that the SRs played a crucial role in an early perception by upregulating key genes, including DcNCED3 (ABA biosynthesis) and DcYUCCA6 (auxin biosynthesis). The abundance of osmolytes (proline; GABA) and carbohydrates (sucrose; glucose; fructose; mannitol; and inositol) was also significantly increased in each tissue. In particular, LRs accumulated high levels of these metabolites and promoted growth under drought conditions. Conclusions: Our findings suggest that the SR acts as a central regulator in the drought response of carrots by synthesizing ABA and auxin, which modulate the accumulation of metabolites and growth of LRs. This study provides new insights into the mechanisms of tissue-specific carrot responses to drought tolerance, emphasizing that the SR plays a key role in improving drought resistance. Full article