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The in vitro cultures of Vachellia farnesiana (L) Wight & Arn. have demonstrated cytotoxic activity through callus extract on the HeLa cell line. Explants excised from in vitro-grown seedlings from seeds of two different locations were inoculated on Murashige and Skoog (MS) culture media containing various concentrations of N-6 benzyladenine (BA) or kinetin with 2,4-dichlorophenoxyacetic acid (2,4-D). Optimal efficiency in friable callus induction (100%) was achieved in leaf explants cultured on MS media containing 2.32 µM BA + 13.57 µM 2,4-D. Plant tissues (callus and leaf) were extracted and subjected to quantitative phytochemical analysis, revealing the highest total alkaloid and phenolic content in leaf extracts from Queretaro adult specimens (339.5 ± 20.9 mg atropine equivalents (AE) per g dry extract (DE) and 158.4 ± 12.5 mg gallic acid equivalents (GAE) per g DE, respectively). In contrast, callus cultures exhibited significantly higher total triterpene content (356–381 mg ursolic acid equivalents (UAE) per g DE) compared to leaf extracts (208–243 mg UAE/g DE). Both leaf and callus extracts displayed cytotoxic activity against the HeLa cell line, with a significantly lower half-maximal inhibitory concentration (IC50) for leaf extracts (28–32 µg/mL) compared to callus cultures (43–66 µg/mL), suggesting that alkaloids were primarily responsible for the cytotoxic activity. Furthermore, this study provides valuable insights into the controlled production of bioactive compounds with cytotoxic activity, with callus serving as a rich source. [ABSTRACT FROM AUTHOR]

Trace levels of biologically precipitated magnetite (Fe3O4) nanocrystals are present in the tissues of many living organisms, including those of plants. Recent work has also shown that magnetite nanoparticles are powerful ice nucleation particles (INPs) that can initiate heterogeneous freezing in supercooled water just below the normal melting temperature. Hence there is a strong possibility that magnetite in plant tissues might be an agent responsible for triggering frost damage, even though the biological role of magnetite in plants is not understood. To test this hypothesis, we investigated supercooling and freezing mortality in cloves of garlic (Allium sativum), a species which is known to have moderate frost resistance. Using superconducting magnetometry, we detected large numbers of magnetite INPs within individual cloves. Oscillating magnetic fields designed to torque magnetite crystals in situ and disturb the ice nucleating process produced significant effects on the temperature distribution of supercooling, thereby confirming magnetite's role as an INP in vivo. However, weak oscillating fields increased the probability of freezing, whereas stronger fields decreased it, a result that predicts the presence of magnetite binding agents that are loosely attached to the ice nucleating sites on the magnetite crystals. Magnetite (Fe3O4) nanocrystals present in many animal and plant tissues are known to be potent ice nucleating particles. Results from a study on garlic predict the presence of magnetite binding agents in plants that help to prevent frostbite. [ABSTRACT FROM AUTHOR]

Abstract\nSTATEMENT OF NOVELTYFour aquatic landscape plants and three veterinary antibiotics were selected to construct a hydroponic test system to analyze the tolerance, removal effect and mechanism of antibiotics. The results indicated that antibiotic concentrations from 0 to 100 μg·L−1 promoted plant heights and leaf chlorophyll contents, while antibiotics at concentrations > 100 μg·L−1 had inhibitory effects. The ability of different plants to remove antibiotics was Acorus calamus L. > Ceratophyllum demersum L. > Thalia dealbata Fraser > Nuphar pumila (Timm) DC. The plants with the best removal of norfloxacin, sulfadimethoxine and chlortetracycline were Ceratophyllum demersum L., Acorus calamus L. and Acorus calamus L. after 12 d of hydroponic cultivation using 100 μg·L−1 antibiotics, with removal rates of 66.6%, 63.0% and 63.2%, respectively. The accumulation of antibiotics in different plant tissues was root > stem > leaf and the accumulation increased with incubation time. The diversity of plant root biofilm microorganisms decreased with increasing treatment concentrations of antibiotics, while the abundance of dominant genera (Aeromonas, Bacillus, Lysinibacillus, Providencia, and Staphylococcus) showed an increasing trend. The findings imply that the antibiotic uptake by plants and the dynamics of the rhizosphere microbial community combine to promote antibiotic removal.Different plants have different removal capacities for pollutants, and optimal plant selection is critical for antibiotic removal in phytoremediation and constructed wetland projects. Currently, although there are a small number of preliminary studies on the effect and mechanism of plant removal of antibiotics from wastewater, there is a lack of systematic understanding of the antibiotic removal capacity, uptake and accumulation characteristics, and possible coupling of microbial communities in the root zone of common aquatic landscape plants. In this study, common veterinary antibiotics (chlortetracycline, sulfadimethoxine, and norfloxacin) were selected as pollutants based on the use of veterinary medicines in farms, and common aquatic landscape plants (Acorus calamus L., Thalia dealbata Fraser, Ceratophyllum demersum L., and Nuphar pumila (Timm) DC.) were selected for hydroponic tests under different concentration treatments of antibiotics. We analyzed the tolerance, removal effect, uptake and accumulation characteristics of these plants to antibiotics in hydroponic solution and the evolutionary pattern of the microbial community in the root zone, in order to improve the understanding of the phytoremediation mechanism of antibiotics in aquatic environments. Meanwhile, this study searched for aquatic landscape plants with superior removal capacity for antibiotics, which was expected to provide a reference for phytoremediation and constructed wetland projects. [ABSTRACT FROM AUTHOR]

Arabidopsis thaliana sepals are excellent models for analyzing growth of entire organs due to their relatively small size, which can be captured at a cellular resolution under a confocal microscope. To investigate how differential growth of connected cell layers generate unique organ morphologies, it is necessary to live-image deep into the tissue. However, imaging deep cell layers of the sepal (or plant tissues in general) is practically challenging. Image processing is also difficult due to the low signal-to-noise ratio of the deeper tissue layers, an issue mainly associated with live imaging datasets. Addressing some of these challenges, we provide an optimized methodology for live imaging sepals, and subsequent image processing. For live imaging early-stage sepals, we found that the use of a bright fluorescent membrane marker, coupled with increased laser intensity and an enhanced Z- resolution produces high-quality images suitable for downstream image processing. Our optimized parameters allowed us to image the bottommost cell layer of the sepal (inner epidermal layer) without compromising viability. We used a 'voxel removal' technique to visualize the inner epidermal layer in MorphoGraphX image processing software. We also describe the MorphoGraphX parameters for creating a 2.5D mesh surface for the inner epidermis. Our parameters allow for the segmentation and parent tracking of individual cells through multiple time points, despite the weak signal of the inner epidermal cells. While we have used sepals to illustrate our approach, the methodology will be useful for researchers intending to live-image and track growth of deeper cell layers in 2.5D for any plant tissue. [ABSTRACT FROM AUTHOR]

AbstractIn hydroponics, preferring a higher nitrate to ammonia ratio can lead to nitrate accumulation in plant tissues. Reducing nitrate application and substituting nitrate-based fertilizers with ammonium or urea can help solve this issue. Additionally, adding molybdenum (Mo) can decrease nitrate accumulation by stimulating nitrate reductase activity. This study was carried out in a factorial design within a completely randomized experimental setup to investigate the effects of varying nitrate, ammonium, and urea ratios, as well as Mo concentration in the nutrient solution, on vegetative growth and biochemical parameters in hydroponically grown Jenovise basil. The treatments included different ratios of nitrate: ammonium: urea (75:25:0, 50:25:25, 25:25:50, 0:25:75, 50:0:50, 25:0:75, 0:0:100, or 100:0:0) and three Mo levels (0.001, 0.01, 0.1 mg. L−1) in a modified Hoagland solution. The results indicated that growth-associated characteristics improved when nitrate was partially substituted with ammonium and urea in the nutrient solution. The highest total phenolics (2.61 mg. g−1 DW) and flavonoids (2500.36 mg. g−1 DW) were observed at a nitrate: ammonium: urea ratio of 75:25:0 with 0.1 mg. L−1 Mo. Plants treated with a nutrient solution containing a nitrate: ammonium: urea ratio of 0:25:75 and 0.01 mg L−1 Mo showed a significant increase in chlorophyll b concentration, reaching 0.22 mg.g−1 FW, which was higher than all other treatments. In conclusion, our findings demonstrated that optimizing the combined nitrate, ammonium, and urea ratios along with Mo in the nutrient solution regulated nitrate accumulation and growth in hydroponically grown basil. [ABSTRACT FROM AUTHOR]

AbstractGeraniol, an acyclic monoterpene alcohol, has significant potential applications in various fields, including: food, cosmetics, biofuels, and pharmaceuticals. However, the current sources of geraniol mainly include plant tissue extraction or chemical synthesis, which are unsustainable and suffer severely from high energy consumption and severe environmental problems. The process of microbial production of geraniol has recently undergone vigorous development. Particularly, the sustainable construction of recombinant Escherichia coli (13.2 g/L) and Saccharomyces cerevisiae (5.5 g/L) laid a solid foundation for the microbial production of geraniol. In this review, recent advances in the development of geraniol-producing strains, including: metabolic pathway construction, key enzyme improvement, genetic modification strategies, and cytotoxicity alleviation, are critically summarized. Furthermore, the key challenges in scaling up geraniol production and future perspectives for the development of robust geraniol-producing strains are suggested. This review provides theoretical guidance for the industrial production of geraniol using microbial cell factories. [ABSTRACT FROM AUTHOR]

Plant tissues harbor abundant endophytes, which are crucial for plant growth. Endophytes present in Alsophila spinulosa, which is enriched with medicinal components, have not been isolated and characterized yet. Here we employed meta-amplicon sequencing to identify endophytic species and examined their diversity in the leaves, petioles, roots and stems of A. spinulosa. Our findings revealed 1,247 operational taxonomic units (OTUs) for endophytic bacteria across 210 species and 476 OTUs for endophytic fungi across 222 species. Alpha diversity analysis showed the highest endophytic bacterial diversity in A. spinulosa roots, whereas fungal diversity was similar across the leaf, petiole and root tissues. Fungal diversity in the leaves and petioles was markedly higher than that in the stems. Furthermore, beta diversity analysis revealed similarities in the endophytic bacterial and fungal compositions between the leaves and petioles, whereas the compositions in roots and stems considerably differed from those in the leaves and petioles. At the genus level, the predominant endophytic bacteria were Methylobacterium-Methylorubrum and Pseudomonas, whereas the predominant endophytic fungi were Cutaneotrichosporon and Pseudofabraea. Linear discriminant analysis effect size revealed characteristic endophytic bacterial genera specific to each tissue type and characteristic endophytic fungal genera specifically in the leaves, petioles and roots. The co-occurrence network analysis indicated that the complexity of endophyte networks was the highest in the leaves and the lowest in the stems of A. spinulosa. Overall, this study elucidates the distribution patterns of endophytes in A. spinulosa across various tissues, offering valuable microbial resources for the development of natural products for medicinal application. [ABSTRACT FROM AUTHOR]

A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer. Author summary: The endocycle is an alternative growth program during which cells increase in size and repeatedly duplicate their DNA without dividing. The switch from cell division cycles to endocycles occurs normally during development of many tissues across plants and animals including humans. Cells can also switch to unscheduled endocycles in response to various conditions. Evidence suggests that this switch is beneficial for wound healing, but also can have pathological effects, most notably in cancer. Much remains unknown, however, about the regulation of these unscheduled endocycles and their impact on tissue growth. Using the Drosophila larval wing disc as model, we have found that unscheduled endocycles are limited in their growth by a specific type of senescent arrest that is mediated by a Jun Kinase stress pathway, which results in severe deleterious effects on tissue growth. We found that these arrested endocycling cells can go back to error prone divisions that compromise genomic DNA integrity, and can also promote the division of neighboring cells. Our study has revealed new inherent properties of unscheduled endocycling cells that impact tissue growth, with important implications for understanding their contribution to wound healing and cancer. [ABSTRACT FROM AUTHOR]

Although many of the structures and organelles of vegetative cells are comparable to those of animal tissues, significant differences between the two kingdoms require modifications in histological techniques for both tissue processing steps and histochemical staining techniques. The authors investigated the challenges of working with plant tissues by collecting various flora to represent the four main plant organs: leaf, stem, root, and flower/fruit. Triplicate samples for each specimen were placed into formalin for paraffin embedding, placed into formalin for later frozen sections, and used fresh to undergo immediate frozen sectioning. Frozen sections of plant tissues were more difficult to obtain than formalin-fixed paraffin-embedded (FFPE) sections, exhibited tissue loss during staining, and were inferior morphologically to FFPE sections. Although, historically, plant tissue fixation and processing has employed several different reagents compared with those used in animal tissue processing and took significantly longer times, the current investigation determined reagents and protocols from a modern histology laboratory which processes mammalian tissues can be applied to plant tissue processing with only slight modifications in respect to reagent timing. Additionally, staining techniques were compared and while it is well known that plant cell walls stain well with safranin O, the current investigation determined the uptake of safranin O can be accelerated by incubating at 60°C. [ABSTRACT FROM AUTHOR]

The action of abscisic acid (ABA) is closely related to its level in plant tissues. Uridine diphosphate-glycosyltransferase71c5 (UGT71C5) was characterized as a major UGT enzyme to catalyze the formation of the ABA-glucose ester (ABA-GE), a reversible inactive form of free ABA in Arabidopsis thaliana (thale cress). UGTs function in a mode where the catalytic base deprotonates an acceptor to allow a nucleophilic attack at the anomeric center of the donor, achieving the transfer of a glucose moiety. The proteomic data revealed that UGT71C5 can be persulfidated. Herein, an experimental method was employed to detect the persulfidation site of UGT71C5, and the computational methods were further used to identify the yet unknown molecular basis of ABA glycosylation as well as the regulatory role of persulfidation in this process. Our results suggest that the linker and the U-shaped loop are regulatory structural elements: the linker is associated with the binding of uridine diphosphate glucose (UPG) and the U-shaped loop is involved in binding both UPG and ABA.It was also found that it is through tuning the dynamics of the U-shaped loop that is accompanied by the movement of tyrosine (Y388) that the persulfidation of cysteine (C311) leads to the catalytic residue histidine (H16) being in place, preparing for the deprotonation of ABA, and then reorientates UPG and deprotonated ABA closer to the 'Michaelis' complex, facilitating the transfer of a glucose moiety. Ultimately, the persulfidation of UGT71C5 is in favor of ABA glycosylation. Our results provide insights into the molecular details of UGT71C5 recognizing substrates and insights concerning persulfidation as a possible mechanism for hydrogen sulfide (H2S) to modulate the content of ABA, which helps us understand how modulating ABA level strengthens plant tolerance. [ABSTRACT FROM AUTHOR]

Summary: Phytohormones possess unique chemical structures, and their physiological effects are regulated through intricate interactions or crosstalk among multiple phytohormones. MALDI‐MSI enables the simultaneous detection and imaging of multiple hormones. However, its application for tracing phytohormones is currently restricted by low abundance of hormone in plant and suboptimal matrix selection.2,4‐Dihydroxy‐5‐nitrobenzoic acid (DHNBA) was reported as a new MALDI matrix for the enhanced detection and imaging of multiple phytohormones in plant tissues. DHNBA demonstrates remarkable sensitivity improvement when compared to the commonly used matrix, 2,5‐dihydroxybenzoic acid (DHB), in the detection of isoprenoid cytokinins (trans‐zeatin (tZ), dihy‐drozeatin (DHZ), meta‐topolin (mT), and N6‐(Δ2‐isopentenyl) adenine (iP)), jasmonic acid (JA), abscisic acid (ABA), and 1‐aminocyclo‐propane‐1‐carboxylic acid (ACC) standards.The distinctive properties of DHNBA (i.e. robust UV absorption, uniform matrix deposition, negligible background interference, and high ionization efficiency of phytohormones) make it as an ideal matrix for enhanced detection and imaging of phytohormones, including tZ, DHZ, ABA, indole‐3‐acetic acid (IAA), and ACC, by MALDI‐MSI in various plant tissues, for example germinating seeds, primary/lateral roots, and nodules.Employing DHNBA significantly enhances our capability to concurrently track complex phytohormone biosynthesis pathways while providing precise differentiation of the specific roles played by individual phytohormones within the same category. This will propel forward the comprehensive exploration of phytohormonal functions in plant science. [ABSTRACT FROM AUTHOR]

Global declines in animal populations suggest global causes. Herbivores are uniquely vulnerable to declines in the nutrient density of the plants they consume. CO 2 pollution is a global agent of nutrient dilution: the impoverishment of plant tissue, bite for bite, of the elements essential for herbivore survival. As plants assimilate higher levels of CO 2 , nutrient dilution can create flammable 'green deserts' of low-quality food for herbivores already limited by elements from nitrogen to sodium to zinc. We posit that nutrient dilution is a key driver – rich in testable predictions – of global declines in herbivore abundance. Its impact should be highest in productive and/or nutrient-poor ecosystems like tropical forests and the open oceans. It is reversed by fertilization. It acts regardless of habitat size or pesticide use. It thus complements these and other agents of herbivore decline. Nutrient dilution (ND) – the decrease in the concentration of nutritional elements in plant tissue – arises from an increase in the mass of carbohydrates and/or a decrease in the 20+ essential elements. Increasing CO 2 levels and its promotion of biomass are linked to nutrient dilution. We build a case for nutrient dilution as a key driver in global declines in herbivore abundance. Herbivores must build element-rich animal tissue from nutrient-poor plant tissue, and their abundance commonly increases with fertilization of both macro- and micronutrients. We predict the global impacts of nutrient dilution will be magnified in some of Earth's most biodiverse, highly productive, and/or nutrient-poor ecosystems and should favor specific traits of herbivores, including sap-feeding and ruminant microbiomes. [ABSTRACT FROM AUTHOR]

This article, published in the journal Plant Pathology, explores the role of trichomes in wheat susceptibility to Fusarium head blight (FHB), a fungal disease that affects wheat worldwide. The study focuses on the infection process of Fusarium graminearum, the predominant causal species for FHB, and describes how the fungus invades the base of trichomes on wheat florets. The research findings suggest that reducing trichome density and thickening the trichome base through genetic engineering could potentially improve wheat resistance to FHB. The article provides valuable insights into the nature of the infection process and may contribute to the development of FHB-resistant wheat cultivars. [Extracted from the article]

SUMMARY: The osmotic resistance mechanism has been extensively studied in whole plants or plant tissues. However, little is known about it in embryogenic tissue (ET) which is widely used in plant‐based biotechnological systems. Suberin, a cell wall aliphatic and aromatic heteropolymer, plays a critical role in plant cells against osmosis stress. The suberin regulatory biosynthesis has rarely been studied in gymnosperms. Here, PaMYB11, a subgroup 11 R2R3‐MYB transcription factor, plays a key role in the osmotic resistance of Norway spruce (Picea abies) ETs during cryoprotectant pretreatment. Thus, RNA‐seq, histological, and analytical chemical analyses are performed on the stable transformations of PaMYB11‐OE and PaMYB11‐SRDX in Norway spruce ETs. DAP‐seq, Y1H, and LUC are further combined to explore the PaMYB11 targets. Activation of PaMYB11 is necessary and sufficient for suberin lamellae deposition on Norway spruce embryogenic cell walls, which plays a decisive role in ET survival under osmotic stress. Transcriptome analysis shows that PaMYB11 enhances suberin lamellae monomer synthesis by promoting very long‐chain fatty acid (VLCFA) synthesis. PaPOP, PaADH1, and PaTET8L, the first two (PaADH1 and PaPOP, included) involved in VLCFA synthesis, are proved to be the direct targets of PaMYB11. Our study identified a novel osmotic response directed by PaMYB11 in Norway spruce ET, which provides a new understanding of the resistance mechanism against osmosis in gymnosperms. Significance Statement: In brief, our data suggested that the activation of PaMYB11 enhances SL accumulation by promoting very long‐chain fatty acids synthesis in Picea abies embryogenic tissues. PaADH1, PaPOP and TET8L are direct targets of PaMYB11. However, the correlation between very long‐chain fatty acids synthesis and the expression of PaADH1, PaPOP and TET8L is still unclear. It provides novel insight into the resistance mechanism against osmosis in gymnosperms. [ABSTRACT FROM AUTHOR]

Elevated CO2 levels (eCO2) pose challenges to wheat (Triticum aestivum L.) growth, potentially leading to a decline in quality and productivity. This study addresses the effects of two ambient CO2 concentrations (aCO2, daytime/nighttime = 410/450 ± 30 ppm and eCO2, 550/600 ± 30 ppm) and two nitrogen (N) supplements (without N supply—N0 and with 100 mg N supply as urea per kg soil—N100) on wheat (T. aestivum cv. Yunmai) growth, N accumulation, and soil microbial communities related to ammonia oxidization. The data showed that the N supply effectively mitigated the negative impacts of eCO2 on wheat growth by reducing intercellular CO2 concentrations while enhancing photosynthesis parameters. Notably, the N supply significantly increased N concentrations in wheat tissues and biomass production, thereby boosting N accumulation in seeds, shoots, and roots. eCO2 increased the agronomic efficiency of applied N (AEN) and the physiological efficiency of applied N (PEN) under N supply. Plant tissue N concentrations and accumulations are positively related to plant biomass production and soil NO3−-N. Additionally, the N supply increased the richness and evenness of the soil microbial community, particularly Nitrososphaeraceae, Nitrosospira, and Nitrosomonas, which responded differently to N availability under both aCO2 and eCO2. These results underscore the importance and complexity of optimizing N supply and eCO2 for enhancing crop tissue N accumulation and yield production as well as activating nitrification-related microbial activities for soil inorganic N availability under future global environment change scenarios. [ABSTRACT FROM AUTHOR]

Cytokinin oxidase/dehydrogenase (CKX) inhibitors reduce the degradation of cytokinins in plants and thereby may improve the efficiency of agriculture and plant tissue culture-based practices. Here, we report a synthesis and structure–activity relationship study of novel urea derivatives concerning their CKX inhibitory activity. The most active compounds showed sub-nanomolar IC50 values with maize ZmCKX1, the lowest value yet documented. Other CKX isoforms of maize and Arabidopsis were also inhibited very effectively. The binding mode of four compounds was characterized based on high-resolution crystal complex structures. Using the soil nematode Caenorhabditis elegans , and human skin fibroblasts, key CKX inhibitors with low toxicity were identified. These compounds enhanced the shoot regeneration of Lobelia , Drosera , and Plectranthus , as well as the growth of Arabidopsis and Brassica napus. At the same time, a key compound (identified as 82) activated a cytokinin primary response gene, ARR5:GUS , and a cytokinin sensor, TCSv2:GUS , without activating the Arabidopsis cytokinin receptors AHK3 and AHK4. This strongly implies that the effect of compound 82 is due to the up-regulation of cytokinin signalling. Overall, this study identifies highly effective and easily prepared CKX inhibitors with a low risk of environmental toxicity for further investigation of their potential in agriculture and biotechnology. [ABSTRACT FROM AUTHOR]

The study of plant–microbe interactions is a rapidly growing research field, with increasing attention to the role of seed-borne microbial endophytes in protecting the plant during its development from abiotic and biotic stresses. Recent evidence suggests that seed microbiota is crucial in establishing the plant microbial community, affecting its composition and structure, and influencing plant physiology and ecology. For Theobroma cacao L., the diversity and composition of vertically transmitted microbes have yet to be addressed in detail. We explored the composition and diversity of seed-borne endophytes in cacao pods of commercial genotypes (ICS95, IMC67), recently liberated genotypes from AGROSAVIA (TCS01, TCS19), and landraces from Tumaco (Colombia) (AC9, ROS1, ROS2), to evaluate microbial vertical transmission and establishment in various tissues during plant development. We observed a higher abundance of Pseudomonas and Pantoea genera in the landraces and AGROSAVIA genotypes, while the commercial genotypes presented a higher number of bacteria species but in low abundance. In addition, all the genotypes and plant tissues showed a high percentage of fungi of the genus Penicillium. These results indicate that domestication in cacao has increased bacterial endophyte diversity but has reduced their abundance. We isolated some of these seed-borne endophytes to evaluate their potential as growth promoters and found that Bacillus, Pantoea, and Pseudomonas strains presented high production of indole acetic acid and ACC deaminase activity. Our results suggest that cacao domestication could lead to the loss of essential bacteria for seedling establishment and development. This study improves our understanding of the relationship and interaction between perennial plants and seed-borne microbiota. [ABSTRACT FROM AUTHOR]

When attacked by insect herbivores, plants emit blends of chemical compounds known as herbivore‐induced plant volatiles (HIPVs). Although HIPVs are produced both aboveground and belowground, how HIPVs vary across plant tissues remains unresolved, as do the selective forces shaping interspecific HIPV emission patterns. Here, we compared foliar and root HIPVs within and among closely related plant species and evaluated if different eco‐evolutionary forces, including plant domestication, coexistence histories with herbivores, or phylogenetic relatedness, explain HIPV blends. To examine aboveground and belowground patterns in HIPVs, we compared leaf and root volatile profiles for six species in the Cucurbitaceae that differed in domestication status and coexistence history with specialist insect herbivores. We predicted that within‐species HIPVs from different tissues would be more similar than HIPV blends among different species, and that plant volatile chemodiversity was reduced by domestication and enhanced by coexistence histories with herbivores. We found that herbivory induced both quantitative and qualitative changes in volatile emissions across all plant species, which were more pronounced aboveground than belowground. Each species produced tissue‐specific HIPVs, and foliar and root HIPVs differed among species. Contrary to our predictions, plant domestication enhanced foliar volatile diversity, while coexistence histories with herbivores reduced foliar and root volatile diversity. Additionally, phylogenetic relatedness did not correlate with aboveground or belowground volatiles. Overall, this work furthers our understanding of the eco‐evolutionary forces driving patterns in aboveground and belowground HIPV emissions, elucidating an important and previously undescribed component of within‐plant variation in chemodiversity. [ABSTRACT FROM AUTHOR]

Mechanisms involved in the supercooling of plant tissues as a means of low temperature survival are still not fully understood. We investigated properties that may promote supercooling in overwintering sweet cherry (Prunus avium) flower buds. We conducted experiments on sweet cherry flower buds using differential thermal analysis (DTA) and observed locations of ice formation in the bud structure. We also used anatomical development and water‐soluble dye uptake throughout the overwintering period to identify changes that correlate with gain and loss of supercooling capacity. Our results revealed barriers to ice propagation are likely unique to each primordium, as inferred from exotherms produced from buds subjected to DTA, although multiple primordia may freeze simultaneously. Ice is accommodated between the bud scales and within the bud axis; however, full expression of supercooling was not dependent on the presence of scales. Anatomical and DTA studies revealed a correlation between vascular differentiation in primordia and loss of supercooling in the spring; these observations were at a higher temporal resolution than previously described for Prunus. Furthermore, disturbing tissues subtending the primordia interfered with typical patterns of supercooling, indicated more erratic and numerous exotherms produced during DTA. In summary, sweet cherry flower buds undergo extra‐organ freezing. In winter, a barrier to ice propagation in the region directly subtending primordia protects the flower from freezing damage, but in the spring xylem differentiation in primordia provides a conduit for ice propagation that compromises supercooling. [ABSTRACT FROM AUTHOR]

Rapid, in situ, and real‐time molecule mapping on rough surfaces with high accuracy has long been one of the paramount challenges in many fields. Here, an effortless Ag NPs doped glycerol liquid film SERS substrate (g‐LFS) is developed to investigate the distribution of contaminants on different types of rough surfaces. After substrate optimization, the g‐LFS is characterized in terms of uniformity, reproducibility, and stability with time. The substrate showed an excellent signal stability, even after 96.5 h of usage or 19 days of storage, together with great uniformity (7.4% RSD) and reproducibility (7.1% RSD). As a proof of concept, the distribution of Rhodamine 6G(R6G) dye on rough fabric and the R6G migration in different plant types and tissues have been explored. The g‐LFS substrate demonstrated great accuracy, detecting R6G even in deep fabric grooves, recovering 82.4% of the initial concentration. Moreover, the g‐LFS SERS substrate detected significantly different concentrations in root, stem and leave tissues of bean sprouts, as well as between xylem and phloem in vascular plant branches. Overall, the g‐LFS substrate is proven to be well‐suited for in situ detection on rough surfaces with great versatility and robustness, aggregating new opportunities for contaminant investigation on food and plants using SERS. [ABSTRACT FROM AUTHOR]

This study aimed to compare the impact of iodosulfuron-methyl-sodium and an iodosulfuron-based herbicidal ionic liquid (HIL) on the microbiomes constituting the epiphytes and endophytes of cornflower (Centaurea cyanus L.). The experiment involved biotypes of cornflower susceptible and resistant to acetolactate synthase inhibition, examining potential bacterial involvement in sulfonylurea herbicide detoxification. We focused on microbial communities present on the surface and in the plant tissues of roots and shoots. The research included the synthesis and physicochemical analysis of a novel HIL, evaluation of shifts in bacterial community composition, analysis of the presence of catabolic genes associated with sulfonylurea herbicide degradation and determination of their abundance in all experimental variants. Overall, for the susceptible biotype, the biodiversity of the root microbiome was higher compared to shoot microbiome; however, both decreased notably after herbicide or HIL applications. The herbicide-resistant biotype showed lower degree of biodiversity changes, but shifts in community composition occurred, particularly in case of HIL treatment. [ABSTRACT FROM AUTHOR]

When a pathogen invades a plant, it encounters a diverse microbiota with some members contributing to the health and growth of the plant host. So far, the relevance of interactions between pathogens and the plant microbiota are poorly understood; however, new lines of evidence suggest that pathogens play an important role in shaping the microbiome of their host during invasion. This review aims to summarize recent findings that document changes in microbial community composition during the invasion of filamentous pathogens in plant tissues. We explore the known mechanisms of interaction between plant pathogens and the host microbiota that underlie these changes, particularly the pathogen-encoded traits that are produced to target specific microbes. Moreover, we discuss the limitations of current strategies and shed light on new perspectives to study the complex interaction networks between filamentous pathogens and the plant microbiome. [ABSTRACT FROM AUTHOR]

Bupleurum is a kind of medicinal plant that has made a great contribution to human health because of the presence of bioactive metabolites: Bupleurum saikosaponins and flavonoids. Despite their importance, it has been a challenge to visually characterize the spatial distribution of these metabolites in situ within the plant tissue, which is essential for assessing the quality of Bupleurum. The development of a new technology to identify and evaluate the quality of medicinal plants is therefore necessary. Here, the spatial distribution and quality characteristics of metabolites of three Bupleurum species: Bupleurum smithii (BS), Bupleurum marginatum var. stenophyllum (BM), and Bupleurum chinense (BC) were characterized by Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). Twenty-nine metabolites, including saikosaponins, non-saikosaponins, and compounds from the saikosaponin synthesis pathway, were characterized. Some of these were successfully localized and visualized in the transverse section of roots. In these Bupleurum species, twelve saikosaponins, five non-saikosaponins, and five saikosaponin synthesis pathway compounds were detected. Twenty-two major influencing components, which exhibit higher ion intensities in higher quality samples, were identified as potential quality markers of Bupleurum. The final outcome indicates that BC has superior quality compared to BS and BM. MALDI-MSI has effectively distinguished the quality of these Bupleurum species, providing an intuitive and effective marker for the quality control of medicinal plants. [ABSTRACT FROM AUTHOR]

Background: The identification of spotted leaf 50 (spl50), a novel lesion mimic mutant (LMM) in rice, provides critical insights into the mechanisms underlying programmed cell death (PCD) and innate immunity in plants. Results: Based on ethyl methane sulfonate (EMS)-induced mutagenesis, the spl50 mutant mimics hypersensitive responses in the absence of pathogen by displaying spontaneous necrotic lesions after the tillering phase. SPL50, an ARM repeat protein essential for controlling reactive oxygen species (ROS) metabolism and boosting resistance to blast disease, was identified by map-based cloning techniques. This work also demonstrates the detrimental effects of spl50 on photosynthetic efficiency and chloroplast development. The crucial significance of SPL50 in cellular signaling and stress response is shown by its localization to the cytoplasm and constitutive expression in various plant tissues. In light of growing concerns regarding global food security, this study highlights the pivotal role of SPL50 in regulating programmed cell death (PCD) and enhancing the immune response in plants, contributing to strategies for improving crop disease resistance. Conclusions: The novel identification of the SPL50 gene in rice, encoding an ARM repeat protein, reveals its pivotal role in regulating PCD and innate immune responses independently of pathogen attack. [ABSTRACT FROM AUTHOR]

A simple and reliable external calibration strategy of LA-ICP-MS for fresh plant soft tissues was developed. The prepared plant suspension was frozen by the designed cryogenic ablation cell and used as external standard for quantitative elemental imaging analysis of fresh plant tissues. The controllable water content of the prepared external standards provides a similar matrix with fresh soft tissues, and a homogeneous elemental distribution could be ensured due to the fine grinding particle sizes. More interestingly, the presence of water increased the signal intensity produced by the suspension by a factor of 1.6 (Pb) to 66.6 (La) compared to that of the pressed cake. The excellent dispersing property and advantage of long-term use were achieved owing to the employment of 0.1% PAANa as suspending agent. A series of plant reference materials were analyzed, and the relative errors of most elements were less than 10 %, indicating that there is a reliable accuracy of the proposed method. The limits of detection (LODs) ranged from 0.1 ng·g−1 (La) to 1279 ng·g−1 (S). This method was used for elemental imaging analysis in rice leaves under arsenic stress, and the results were consistent with previous studies, which mean that the proposed method could provide technical support for researchers in the fields of agriculture and environment. [ABSTRACT FROM AUTHOR]

Virus-Induced Gene Silencing (VIGS) is a versatile tool in plant science, yet its application to non-model species like sunflower demands extensive optimization due to transformation challenges. In this study, we aimed to elucidate the factors that significantly affect the efficiency of Agrobacterium-VIGS in sunflowers. After testing a number of approaches, we concluded that the seed vacuum technique followed by 6 h of co-cultivation produced the most efficient VIGS results. Genotype-dependency analysis revealed varying infection percentages (62–91%) and silencing symptom spreading in different sunflower genotypes. Additionally, we explored the mobility of tobacco rattle virus (TRV) and phenotypic silencing manifestation (photo-bleaching) across different tissues and regions of VIGS-infected sunflower plants. We showed the presence of TRV is not necessarily limited to tissues with observable silencing events. Finally, time-lapse observation demonstrated a more active spreading of the photo-bleached spots in young tissues compared to mature ones. This study not only offers a robust VIGS protocol for sunflowers but also provides valuable insights into genotype-dependent responses and the dynamic nature of silencing events, shedding light on TRV mobility across different plant tissues. [ABSTRACT FROM AUTHOR]

Cynara cardunculus L. (cardoon) is a wild species of the Mediterranean basin and is highly appreciated due to its rich nutritional value and versatile industrial applications. It is widely known that environmental conditions, such as air temperature, humidity, and solar radiation, among others, play a crucial role in plant phenological variations and the chemical composition and bioactive properties of different plant tissues of cardoon. This study applied several statistical methods to uncover the variations in biomolecules of different cardoon tissues collected in Greece over the growth cycle. The influence of the different seasons on the species is evident, resulting in a clear discrimination between the samples harvested throughout the growth cycle. In addition, the observed fluctuations in chemical composition are consistent with each vegetable tissue's functions and the plant's different physiological processes. This work allows for a better understanding and knowledge of the species, encouraging more profitable and sustainable use of all the plant parts. [ABSTRACT FROM AUTHOR]

Herbal medicines (HMs) have long played a pivotal role in preventing and treating various human diseases and have been studied widely. However, the complexities present in HM metabolites and their unclear mechanisms of action have posed significant challenges in the modernization of traditional Chinese medicine (TCM). Over the past two decades, mass spectrometry imaging (MSI) has garnered increasing attention as a robust analytical technique that enables the simultaneous execution of qualitative, quantitative, and localization analyses without complex sample pretreatment. With advances in technical solutions, MSI has been extensively applied in the field of HMs. MSI, a label-free ion imaging technique can comprehensively map the spatial distribution of HM metabolites in plant native tissues, thereby facilitating the effective quality control of HMs. Furthermore, the spatial dimension information of small molecule endogenous metabolites within animal tissues provided by MSI can also serve as a supplement to uncover pharmacological and toxicological mechanisms of HMs. In the review, we provide an overview of the three most common MSI techniques. In addition, representative applications in HM are highlighted. Finally, we discuss the current challenges and propose several potential solutions. We hope that the summary of recent findings will contribute to the application of MSI in exploring metabolites and mechanisms of action of HMs. [ABSTRACT FROM AUTHOR]

The management of nitrogen (N) fertilization is of fundamental importance in hydroponics. To reduce the supply of nitrate (NO3-) in fertigation recipes for Batavia lettuce crops grown in closed hydroponics, partial replacement of nitrate by chloride (NO3-/Cl-) at different ratios but with the same equivalent sum was experimentally tested. The experiment included four nutritional treatments in the replenishment nutrient solution, particularly T1; 0.7mMCl-/19mMNO3-, T2;2mM Cl-/17.7 mM NO3-, T3; 4 mM Cl-/15.7 mM NO3- and T4; 6 mM Cl-/13.7 mM NO3-. The results showed that reducing nitrate supply combinedwith equivalent increase in chloride application gradually reduced the gap between nitrate input and nitrogen uptake concentrations, with the smallest differences occurring in T4 treatment, which reduced the nitrate concentration in the drainage by 50%. The tested treatments led to very small variations in plant water uptake, production of fresh biomass and nutritional quality, which is justified by the proper functioning of key physiological mechanisms, such as stomatal conductance, which was followed by an increased efficiency of nitrogen use up to 25% (kg fresh biomass kg-1 N supply). The steady level of C/N ratio in the plant tissue irrespective of NO3-/Cl- supply ratio points to sufficiency in photosynthetic products and adequacy in the supply of nitrogen, although leaf Cl- content increased up to 19.6 mg g-1 dry weight in the lowest NO3-/Cl- treatment. Nutrient uptake concentrations were determined as follows: 13.4 (N), 1.72 (P), 10.2 (K), 3.13 (Ca), 0.86 (Mg,mmol L-1), 27.8 (Fe), 5.63 (Mn), 5.45 (Zn) and 0.72 (Cu, mmol L-1). This study suggests that replacing 30% of NO3- supply with Cl- in fertigation recipes for hydroponic lettuce crops reduces leaf nitrate content without affecting physiological processes, growth, and quality, verifying in parallel the role of chloride as a beneficial macronutrient. Finally, a relationship between Cl- uptake and its concentration in the root zone solution was established enabling the simulation of chloride towater consumption. [ABSTRACT FROM AUTHOR]

The use of exotic grasses of African origin for pastures in Brazil has been a major advancement in livestock production, but little is known about the responses of these grasses to nitrogen fertilizers associated with shading. In this study, the morphogenetic, structural, and leaf anatomical characteristics of Megathyrsus maximus cultivars' Tamani and Quênia were investigated as a function of N dose and shade. Morphogenetic and structural characteristics and leaf anatomy were studied under three shading levels (0, 30, and 50 %) and four N doses (0, 100, 200, and 300 kg N ha-1) to simulate growth in a silvopastoral system. When comparing the cultivars, Quênia was more efficient in terms of phyllochron up to fertilization with 100 kg N ha-1. The leaf senescence rate of Tamani was higher than that of Quênia at the 30 and 50 % shade levels. The total area (TA) occupied by leaf tissues decreased in Quênia as a function of the increase in N fertilization, whereas the TA of Tamani did not change. The thickness of the adaxial epidermis was greater in Quênia (0.68 µm) than in Tamani (0.50 µm) when not fertilized. The area occupied by the mesophyll was greater in both cultivars when they received fertilization equivalent to 300 kg N ha-1. Quênia grass has a smaller phyllochron than Tamani grass, due to the rapid reconstruction of its photosynthetic apparatus, especially when it receives higher levels of nitrogen fertilization. However, Tamani grass has a greater distribution of plant tissues. The mesophyll area is larger in Tamani grass due to the greater presence of chloroplasts, which facilitates digestion by animals. The Tamani modified the leaf anatomical tissues more significantly in relation to shading, whereas the Quênia modified them in relation to N fertilization, which reinforces the suggestion of a more appropriate use of Tamani in silvopastoral systems. [ABSTRACT FROM AUTHOR]

The ecological interaction between fleshy fruits and frugivores is influenced by diverse mixtures of secondary metabolites that naturally occur in the fruit pulp. Although some fruit secondary metabolites have a primary role in defending the pulp against antagonistic frugivores, these metabolites also potentially affect mutualistic interactions. The physiological impact of these secondary metabolites on mutualistic frugivores remains largely unexplored. Using a mutualistic fruit bat (Carollia perspicillata), we showed that ingesting four secondary metabolites commonly found in plant tissues affects bat foraging behavior and induces changes in the fecal metabolome. Our behavioral trials showed that the metabolites tested typically deter bats. Our metabolomic surveys suggest that secondary metabolites alter, either by increasing or decreasing, the absorption of essential macronutrients. These behavioral and physiological effects vary based on the specific identity and concentration of the metabolite tested. Our results also suggest that a portion of the secondary metabolites consumed is excreted by the bat intact or slightly modified. By identifying key shifts in the fecal metabolome of a mutualistic frugivore caused by secondary metabolite consumption, this study improves our understanding of the effects of fruit chemistry on frugivore physiology. [ABSTRACT FROM AUTHOR]

Aims The Gram-negative bacterium Erwinia amylovora (Ea) is the causal agent of fire blight, a devastating disease of apples and pears. In the fire blight disease cycle, Ea grows in different plant tissues, each presenting a distinct nutrient environment. Here, we investigate the ability of aspartate and tyrosine double auxotroph Ea lines to proliferate on apple flower stigma surfaces representing the epiphytic growth stage of Ea and in developing fruitlets representing one endophytic growth stage of Ea. Methods and results Heterologous complementation studies in an Escherichia coli aspartate and tyrosine auxotroph verify that Ea aspartate aminotransferase (AspC) and tyrosine aminotransferase (TyrB) act as aspartate and tyrosine amino transferases. Growth analysis reveals that Ea aspC tyrB mutants multiply to near-wild-type levels on apple flower stigmas and immature fruitlets. Conclusions Ea AspC and TyrB are reciprocally complementing for aspartate and tyrosine synthesis in Ec and in Ea. Ea aspC and tyrB mutants obtain sufficient aspartate and tyrosine to support multiplication on stigma surfaces and virulence in immature fruitlets. [ABSTRACT FROM AUTHOR]

Cocoa (Theobroma cacao L.) is one of the leading commodities in Indonesia. Cocoa pod husk is part of the mesocarp or part of the cacao pod husk that wraps the cocoa beans. Endophytic bacteria are microbes that live in host plant tissues and do not interfere with host plant growth. This study aimed to determine characteristics of endophytic bacterial isolates contained in endocarp cocoa pod husk and to determine the antioxidant power of endophytic bacterial isolates contained in cocoa pod husk. Isolation of endophytic bacteria from the inner pod of cocoa which be expected to produce antioxidants has been carried out. Isolation of bacteria using surface sterilization method. Antioxidant test using DPPH method (1,1-diphenyl-2-picrylhydrazyl) with UV-Vis spectrophotometer at 600 nm. Two isolates out of four endophytic bacteria were obtained from the results of the preliminary test of phenolic tests, namely isolates of bacteria KK2 and KK3 which had different colony morphology. The results of the secondary metabolite test showed that the bacterial isolates KK2 and KK3 contained flavonoids and phenolics. Based on the test results, the value of IC50 of bacterial isolate KK2 was 2104.58 ppm and KK3 bacterial isolate was 1123.04 ppm. The highest antioxidant activity was possessed by bacterial isolate KK3 and was classified as a very weak antioxidant. [ABSTRACT FROM AUTHOR]

Global biogeochemical cycles have been widely altered due to human activities, potentially compromising the ability of plants to regulate their metabolism. We grew experimental herbaceous communities simulating the understory of eucalypt forests from southeastern Australia to evaluate the effects of elevated CO2 (400 vs. 650 ppm) and changes in soil resource availability (high-low water and high-low P) on the concentration of fourteen essential plant macro- and micronutrients, and their degree of coupling. Coupling was based on correlations among all elements in absolute value and a null modeling approach. According to the ancient nature of Australian soils, P addition was the main driver of changes in plant tissue chemistry, increasing the concentrations of P, Mg, Ca, and Mn and reducing the concentrations of C, N, S, Na, and Cu. Most treatment combinations showed coupled patterns of plant elements, particularly under ambient CO2. However, under elevated CO2, elements in plant tissues became more decoupled, which was interpreted as the result of a lack of enough supply of a range of elements to satisfy greater demands. Across treatments, P, Mn, and N were the least coupled elements, while K, Ca, and Fe were the most coupled ones. We provide evidence that plant element coupling was positively related to the concentration and coupling of elements measured in soils worldwide, suggesting that plant element coupling is conserved. Our results provide compelling evidence that evaluating the coupling of a representative range of chemical elements in plant tissues may represent a highly novel and powerful indicator of nutritional mismatches between demand and supply under specific environmental circumstances, including in a resource-altered global change context. [ABSTRACT FROM AUTHOR]

Plants continuously face various environmental stressors throughout their lifetime. To be able to grow and adapt in different environments, they developed specialized tissues that allowed them to maintain a protected yet interconnected body. These tissues undergo specific primary and secondary cell wall modifications that are essential to ensure normal plant growth, adaptation and successful land colonization. The composition of cell walls can vary among different plant species, organs and tissues. The ability to remodel their cell walls is fundamental for plants to be able to cope with multiple biotic and abiotic stressors. A better understanding of the changes taking place in plant cell walls may help identify and develop new strategies as well as tools to enhance plants' survival under environmental stresses or prevent pathogen attack. Since the invention of microscopy, numerous imaging techniques have been developed to determine the composition and dynamics of plant cell walls during normal growth and in response to environmental stimuli. In this review, we discuss the main advances in imaging plant cell walls, with a particular focus on fluorescent stains for different cell wall components and their compatibility with tissue clearing techniques. Lay Description: Plants are continuously subjected to various environmental stresses during their lifespan. They evolved specialized tissues that thrive in different environments, enabling them to maintain a protected yet interconnected body. Such tissues undergo distinct primary and secondary cell wall alterations essential to normal plant growth, their adaptability and successful land colonization. Cell wall composition may differ among various plant species, organs and even tissues. To deal with various biotic and abiotic stresses, plants must have the capacity to remodel their cell walls. Gaining insight into changes that take place in plant cell walls will help identify and create novel tools and strategies to improve plants' ability to withstand environmental challenges. Multiple imaging techniques have been developed since the introduction of microscopy to analyse the composition and dynamics of plant cell walls during growth and in response to environmental changes. Advancements in plant tissue cleaning procedures and their compatibility with cell wall stains have significantly enhanced our ability to perform high‐resolution cell wall imaging. At the same time, several factors influence the effectiveness of cleaning and staining plant specimens, as well as the time necessary for the process, including the specimen's size, thickness, tissue complexity and the presence of autofluorescence. In this review, we will discuss the major advances in imaging plant cell walls, with a particular emphasis on fluorescent stains for diverse cell wall components and their compatibility with tissue clearing techniques. We hope that this review will assist readers in selecting the most appropriate stain or combination of stains to highlight specific cell wall components of interest. [ABSTRACT FROM AUTHOR]

The ability of bacteria to colonize diverse environmental niches is often linked to their competence in biofilm formation. It depends on the individual characteristics of a strain, the nature of the colonized surface (abiotic or biotic), or the availability of certain nutrients. Pseudomonas donghuensis P482 efficiently colonizes the rhizosphere of various plant hosts, but a connection between plant tissue colonization and the biofilm formation ability of this strain has not yet been established. We demonstrate here that the potential of P482 to form biofilms on abiotic surfaces and the structural characteristics of the biofilm are influenced by the carbon source available to the bacterium, with glycerol promoting the process. Also, the type of substratum, polystyrene or glass, impacts the ability of P482 to attach to the surface. Moreover, P482 mutants in genes associated with motility or chemotaxis, the synthesis of polysaccharides, and encoding proteases or regulatory factors, which affect biofilm formation on glass, were fully capable of colonizing the root tissue of both tomato and maize hosts. Investigating the role of cellular factors in biofilm formation using these plant-associated bacteria shows that the ability of bacteria to form biofilm on abiotic surfaces does not necessarily mirror its ability to colonize plant tissues. Our research provides a broader perspective on the adaptation of these bacteria to various environments. [ABSTRACT FROM AUTHOR]

SUMMARY: Redox changes of pyridine nucleotides in cellular compartments are highly dynamic and their equilibria are under the influence of various reducing and oxidizing reactions. To obtain spatiotemporal data on pyridine nucleotides in living plant cells, typical biochemical approaches require cell destruction. To date, genetically encoded fluorescent biosensors are considered to be the best option to bridge the existing technology gap, as they provide a fast, accurate, and real‐time readout. However, the existing pyridine nucleotides genetically encoded fluorescent biosensors are either sensitive to pH change or slow in dissociation rate. Herein, we employed the biosensors which generate readouts that are pH stable for in planta measurement of NADH/NAD+ ratio and NADPH level. We generated transgenic Arabidopsis lines that express these biosensors in plastid stroma and cytosol of whole plants and pollen tubes under the control of CaMV 35S and LAT52 promoters, respectively. These transgenic biosensor lines allow us to monitor real‐time dynamic changes in NADH/NAD+ ratio and NADPH level in the plastids and cytosol of various plant tissues, including pollen tubes, root hairs, and mesophyll cells, using a variety of fluorescent instruments. We anticipate that these valuable transgenic lines may allow improvements in plant redox biology studies. Significant Statement: Monitoring dynamic changes in pyridine nucleotides (e.g., NADPH and NADH/NAD+ ratio) in plants at the subcellular level is a major obstacle in plant bioenergetics research. Genetically encoded fluorescent biosensors are considered to be the best option so far because they provide fast, accurate, and real‐time readouts. Here, we present a detailed study on the application of pyridine nucleotide biosensors, and we anticipate that these transgenic lines will be useful in plant redox biology studies. [ABSTRACT FROM AUTHOR]

In plant‐associated communities, foraging insects aim to find different resources of interest. Herbivores look for the most nutritious plant tissues, pollinators for sweet nectar and protein‐rich pollen, and carnivores for their preferred prey. Although these foragers look for different resources, they face similar problems: resource cues are often highly variable and need to be detected in complex environments among non‐resources. Search templates—a subset of stimuli that is likely correlated with the occurrence of a particular resource—help foragers across trophic levels to find their resources. However, search‐template‐based foraging can also cause perception errors.Here, we synthesize knowledge on foraging by insects from functional groups belonging to different trophic levels to reveal common problems experienced by foragers and strategies to solve such problems. We focus mostly on volatile‐based foraging because this searching strategy is best studied across functional groups.We argue that search templates are both multimodal (including multiple trait types, e.g. odour and visual) and hierarchical (including multiple foraging steps). Search templates are plastic and updated by experience to match the dynamic foraging environment over time.By comparing insects from different functional groups spanning multiple trophic levels, we have identified important missing gaps on cue use and foraging strategies which should be addressed in the future in order to reduce knowledge asymmetries among functional groups about search‐template‐based foraging. We propose a way to achieve this goal arguing that studies on less well investigated functional groups can advance rapidly by borrowing, testing and adjusting already available hypotheses and theories formulated for other insect groups. Knowledge of search‐template‐based foraging across functional groups will give new insights into the evolution of foraging behaviour in complex ecological communities, help predict ecological consequences of large‐scale human‐made disturbances and help optimize insect‐delivered ecosystem services (pollination and biological control) in cropping systems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Although seagrasses are expected to thrive in future acidified oceans by overcoming low CO2 diffusion into plant tissues, the co‐occurrence of environmental stressors may affect their growth. Volcanic CO2 vents are often associated with toxic gases and metal‐rich fluids representing ideal sites to assess the effects of multiple stressors. We evaluated the response of Posidonia oceanica growing near shallow CO2 vents characterized by H2S spill‐out by comparing meadow structure and phenology to an area with no gas emissions. Seagrass descriptors at meadow, shoot and leaf level indicated that P. oceanica experienced stressful conditions at the vent area, in clear contrast to the flourishing features of P. oceanica previously described at CO2 vents with no evidence of toxic inputs. Furthermore, the reduction in both leaf δ34S and growth at the vent area indicates that sulfide intrusion occurs and affects seagrass growth performance, dampening the expected beneficial effects of high CO2 levels. [ABSTRACT FROM AUTHOR]

Periderm is a well‐known structural feature with vital roles in protection of inner plant tissues and wound healing. Despite its importance to plant survival, knowledge of periderm occurrences outside the seed plants is limited and the evolutionary origins of periderm remain poorly explored. Here, we review the current knowledge of the taxonomic distribution of periderm in its two main forms – canonical periderm (periderm formed as a typical ontogenetic stage) and wound periderm (periderm produced as a self‐repair mechanism) – with a focus on major plant lineages, living and extinct. We supplement the published occurrences with data based on our own observations and experiments. This updated body of data reveals that the distribution of wound periderm is more widespread taxonomically than previously recognized and some living and extinct groups are capable of producing wound periderm, despite canonical periderm being absent from their normal developmental program. A critical review of canonical and wound periderms in extant and fossil lineages indicates that not all periderms are created equal. Their organisation is widely variable and the differences can be characterised in terms of variations in three structural features: (i) the consistency in orientation of periclinal walls within individual files of periderm cells; (ii) the lateral coordination of periclinal walls between adjacent cell files; and (iii) whether a cambial layer and conspicuous layering of inward and outward derivatives can be distinguished. Using a new system of scoring periderm structure based on these criteria, we characterise the level of organisation of canonical and wound periderms in different lineages. Looking at periderms through the lens provided by their level of organisation reveals that the traditional image of periderm as a single generalised feature, is best viewed as a continuum of structural configurations that are all predicated by the same basic process (periclinal divisions), but can fall anywhere between very loosely organized (diffuse periclinal growth) to very tightly coordinated (organized periclinal growth). Overall, wound periderms in both seed plants and seed‐free plants have lower degrees of organisation than canonical periderms, which may be due to their initiation in response to inherently disruptive traumatic events. Wound and canonical periderms of seed plants have higher degrees of organisation than those of seed‐free plants, possibly due to co‐option of the programs responsible for organizing their vascular cambial growth. Given the importance of wound periderm to plant survival, its widespread taxonomic distribution, and its early occurrence in the fossil record, we hypothesise that wound periderm may have had a single origin in euphyllophytes and canonical periderm may have originated separately in different lineages by co‐option of the basic regulatory toolkit of wound periderm formation. In one evolutionary scenario, wound periderm regulators activated initially by tissue tearing due to tensional stresses elicited by woody growth underwent heterochronic change that switched their activation trigger from tissue tearing to the tensional stresses that precede it, with corresponding changes in the signalling that triggered the regulatory cascade of periderm development from tearing‐induced signals to signalling induced by tension in cells. [ABSTRACT FROM AUTHOR]

The mechanism by which nitrate inhibits nitrogen fixation in soybean (Glycine max L.) is not fully understood. Accumulation of ureide in soybean plant tissues may regulate the nitrogen fixation capacity through a feedback pathway. In this study, unilaterally nodulated dual-root soybeans prepared by grafting were grown in sand culture. They were subjected to the removal of the nodulated side roots, and were given either nitrate supply or no supply to the non-nodulated side roots for 3 days (experiment I). Additionally, they received nitrate supply to the non-nodulated side roots for 1–14 days (experiment II). The results showed that nitrate supply increased the levels of asparagine and ureide in soybean shoots (Experiment I). In Experiment II, nodule dry weight, nodule number, nodule nitrogenase activity, and nodule urate oxidase activity decreased significantly after 3, 7, and 14 days of nitrate supply. Ureide content in the shoots and nodules increased after 1, 3, and 7 days of nitrate supply, but decreased after 14 days of nitrate supply. There was a significant positive correlation between urate oxidase activity and nitrogenase activity. Hence, we deduced that nitrate supply increased the asparagine content in soybean shoots, likely inhibiting ureide degradation, which induced the accumulation of ureide in soybean shoots and nodules, and, in turn, feedback inhibited the nodule nitrogen fixation. In addition, urate oxidase activity can be used to assess the nitrogen fixation capacity of nodules. [ABSTRACT FROM AUTHOR]

The presence and localization of plant metabolites are indicative of physiological processes, e.g., under biotic and abiotic stress conditions. Further, the chemical composition of plant parts is related to their quality as food or for medicinal applications. Mass spectrometry imaging (MSI) has become a popular analytical technique for exploring and visualizing the spatial distribution of plant molecules within a tissue. This review provides a summary of mass spectrometry methods used for mapping and identifying metabolites in plant tissues. We present the benefits and the disadvantages of both vacuum and ambient ionization methods, considering direct and indirect approaches. Finally, we discuss the current limitations in annotating and identifying molecules and perspectives for future investigations. [ABSTRACT FROM AUTHOR]

IntroductionMethodsKey results and conclusionsBryophyte herbarium material often contains inadvertently collected bryophilous fungi preserved with their host plant tissues, providing snapshots of the biotic aspects of bryophyte ecology in space and time. During an ongoing project to study bryophilous fungi on leafy liverworts in the genus Gymnomitrion, new records of the bryophilous ascomycete Bryobroma gymnomitrii (≡ Bryomyces gymnomitrii) were discovered in herbarium material from areas in which the fungus was previously unknown. While many host vouchers were screened, the fungus was observed in only five collections. Using B. gymnomitrii as a case study, some of the advantages and limitations associated with the utility of bryophyte collections for bryo-mycological analyses are considered.More than 400 herbarium specimens from across Europe and North America were screened for the presence of fungi by different researchers at the following four herbaria: ALA, BBSUK, NMW and OSC.Bryobroma gymnomitrii appears to be specific to Gymnomitrion concinnatum and G. corallioides, forming gregarious, black perithecioid fruitbodies on the lower parts of host shoots. The study expands the known distribution of the fungus from a stronghold in northern and northeastern Europe to include the Aleutian Islands in Alaska. One of the host bryophytes, G. corallioides, is threatened by deterioration of its high-altitude Arctic-montane habitats, especially along the southern parts of its range, including Britain and Ireland. Our work supports the concept that research utilising herbarium material may provide valuable, unexpected outcomes, with bryophytes as important sources of fungi that have been inadvertently collected in the past. [ABSTRACT FROM AUTHOR]

ABSTRACT Although green light (GL) is located in the middle of the visible light spectrum and regulates a series of plant developmental processes, the mechanism by which it regulates seedling development is largely unknown. In this study, we demonstrated that GL promotes atypical photomorphogenesis in Arabidopsis thaliana via the dual regulations of phytochrome B (phyB) and phyA. Although the Pr‐to‐Pfr conversion rates of phyB and phyA under GL were lower than those under red light (RL) in a fluence rate‐dependent and time‐dependent manner, long‐term treatment with GL induced high Pfr/Pr ratios of phyB and phyA. Moreover, GL induced the formation of numerous small phyB photobodies in the nucleus, resulting in atypical photomorphogenesis, with smaller cotyledon opening angles and longer hypocotyls in seedlings compared to RL. The abundance of phyA significantly decreased after short‐ and long‐term GL treatments. We determined that four major PHYTOCHROME‐INTERACTING FACTORs (PIFs: PIF1, PIF3, PIF4, and PIF5) act downstream of phyB in GL‐mediated cotyledon opening. In addition, GL plays opposite roles in regulating different PIFs. For example, under continuous GL, the protein levels of all PIFs decreased, whereas the transcript levels of PIF4 and PIF5 strongly increased compared with dark treatment. Taken together, our work provides a detailed molecular framework for understanding the role of the antagonistic regulations of phyB and phyA in GL‐mediated atypical photomorphogenesis. [ABSTRACT FROM AUTHOR]

We present a new set of computational tools that enable accurate and widely applicable 3D segmentation of nuclei in various 3D digital organs. We have developed an approach for ground truth generation and iterative training of 3D nuclear segmentation models, which we applied to popular CellPose, PlantSeg and StarDist algorithms. We provide two high-quality models trained on plant nuclei that enable 3D segmentation of nuclei in datasets obtained from fixed or live samples, acquired from different plant and animal tissues, and stained with various nuclear stains or fluorescent protein-based nuclear reporters. We also share a diverse high-quality training dataset of about 10,000 nuclei. Furthermore, we advanced the MorphoGraphX analysis and visualization software by, among other things, providing a method for linking 3D segmented nuclei to their surrounding cells in 3D digital organs. We found that the nuclear-tocell volume ratio varies between different ovule tissues and during the development of a tissue. Finally, we extended the PlantSeg 3D segmentation pipeline with a proofreading tool that uses 3D segmented nuclei as seeds to correct cell segmentation errors in difficult-to-segment tissues. [ABSTRACT FROM AUTHOR]

Decellularization of plant tissues is an emerging route to fabricate scaffolds for tissue engineering and regenerative medicine. Although significant progress has been made in the field of plant tissue decellularization, functionalization of plant scaffolds is still an emerging field, and loading them with L-ascorbic acid to promote skin regeneration has not yet been reported. L-ascorbic acid is an antioxidant that plays a key role in collagen synthesis as a cofactor of lysyl hydroxylase and prolyl hydroxylase. It has been shown to have significant importance in physiological wound healing by stimulating fibroblasts to produce collagen at both the molecular and the genetic levels. In this work, we aimed to fabricate an ascorbic acid-releasing bioactive scaffold by introducing a stable form of ascorbic acid, L-ascorbic acid 2-phosphate (AA2P), into decellularized baby spinach leaves and investigated its biological activity in vitro. Our results demonstrated that AA2P could be easily introduced into decellularized baby spinach leaf scaffolds and subsequently released within the effective dose range. AA2P-releasing baby spinach leaves were found to increase metabolic activity and enhance collagen synthesis in L929 fibroblasts after 21 days. In conclusion, this study demonstrated the fabrication of a novel functionalized skin tissue engineering scaffold and made a significant contribution to the fields of plant decellularization and skin tissue engineering. [ABSTRACT FROM AUTHOR]

AbstractSoluble fertilizers are among the main costs in strawberry production, so knowing the nutrients balance in plant tissue is essential. In this sense, the Compositional Nutrient Diagnosis (CND) method is presented as a multivariate analysis tool for the nutritional diagnosis of the crop. The main goal of this paper was to establish CND standards and critical nutrient levels in strawberries cultivated in a soilless system. This study uses the Compositional Nutrient Diagnosis (CND) method to analyze nutrient levels grown in a soilless system. Commercial production greenhouses were evaluated for yield and leaf nutrients contents to develop the standards. Data were collected from 52 plots, each consisting of diagnostic leaves from 10 plants, and subsequently analyzed to determine critical nutrient deficiencies and excesses. The CND methodology was sensitive in diagnosing the differences between high and low-yield populations. Thus, adjusting the critical nutrient levels for soilless strawberry cultivation was possible. Due to deficiency, the most limiting nutrients for strawberry production were N, Mg, and S, and Zn and Cu due to excess. Results indicate specific nutrient thresholds, with significant findings from the integration of all indices, it was possible to calculate the sufficiency ranges for soilless strawberry: N = 26–31, P = 4–7, K = 8–11, Ca = 10–15, Mg = 3–4, S = 0.3–0.5 in g kg−1, and B = 18–95, Cu = 1–2, Fe = 46–96, Mn = 80–203, Zn = 1–40, Mo = 1.3–2.7, Ni = 0.1–0.4 in mg kg−1. [ABSTRACT FROM AUTHOR]

Galanthamine is an immensely valuable alkaloid exhibiting anti-cancer and antiviral activity. The cultivation of plant tissues in in vitro conditions is a good source for the synthesis and enrichment of secondary metabolites of commercial interest. In this study, the Amaryllidaceae alkaloid galanthamine was quantified in three Zephyranthes species, such as Zephyranthes candida, Zephyranthes grandiflora, and Zephyranthes citrina, and the impact of the methyl jasmonate (MJ) signaling molecule on galanthamine accumulation was monitored in in vitro-derived plant tissues. This is the first ever study of the MJ-regulated accumulation of galanthamine in in vitro-grown Zephyranthes tissues. Shoot regeneration was obtained in all three Zephyranthes species on Murashige and Skoog (MS) medium containing 2.0 mgL−1 benzylaminopurine (BAP) + 0.5 mgL−1 naphthalene acetic acid (NAA). The regenerated shoots were rooted on a medium containing 2.0 mgL−1 indole butyric acid (IBA). A GC-MS study of Zephyranthes extracts revealed the presence of 34 phyto-compounds of varied levels with therapeutic activities against diseases. The galanthamine content was quantified in plant parts of the three Zephyranthes species using high-performance thin layer chromatography (HPTLC); the maximum was found in Z. candida bulb (2.41 µg g−1 dry wt.), followed by Z. grandiflora (2.13 µg g−1 dry wt.), and then Z. citrina (2.02 µg g−1 dry wt.). The galanthamine content showed bulb > leaf > root source order. The in vitro-generated plantlets were treated with different MJ concentrations, and the galanthamine yield was measured in bulb, leaf, and root tissues. The highest galanthamine content was recorded in bulbs of Z. candida (3.97 µg g−1 dry wt.) treated with 150 µM MJ, showing an increase of 64.73% compared to the control. This accumulation may be attributed to MJ-induced stress, highlighting the potential commercial synthesis of galanthamine in vitro. [ABSTRACT FROM AUTHOR]

The P-type ATPase superfamily genes are the cation and phospholipid pumps that transport ions across the membranes by hydrolyzing ATP. They are involved in a diverse range of functions, including fundamental cellular events that occur during the growth of plants, especially in the reproductive organs. The present work has been undertaken to understand and characterize the P-type ATPases in the pigeonpea genome and their potential role in anther development and pollen fertility. A total of 59 P-type ATPases were predicted in the pigeonpea genome. The phylogenetic analysis classified the ATPases into five subfamilies: eleven P1B, eighteen P2A/B, fourteen P3A, fifteen P4, and one P5. Twenty-three pairs of P-type ATPases were tandemly duplicated, resulting in their expansion in the pigeonpea genome during evolution. The orthologs of the reported anther development-related genes were searched in the pigeonpea genome, and the expression profiling studies of specific genes via qRT-PCR in the pre- and post-meiotic anther stages of AKCMS11A (male sterile), AKCMS11B (maintainer) and AKPR303 (fertility restorer) lines of pigeonpea was done. Compared to the restorer and maintainer lines, the down-regulation of CcP-typeATPase22 in the post-meiotic anthers of the male sterile line might have played a role in pollen sterility. Furthermore, the strong expression of CcP-typeATPase2 in the post-meiotic anthers of restorer line and CcP-typeATPase46, CcP-typeATPase51, and CcP-typeATPase52 in the maintainer lines, respectively, compared to the male sterile line, clearly indicates their potential role in developing male reproductive organs in pigeonpea. [ABSTRACT FROM AUTHOR]

To be effective, a biocontrol agent must survive and persist in the same habitat as the target species and reduce target population growth. When multiple biocontrol agents are used against a single invasive species, they may each perform better under a subset of the habitat in which the target lives. This complementarity allows for a more consistent level of control and a higher resilience to environmental variability. Two species that feed on the same plant tissues would compete, but niche partitioning in the native range may be replicated when both species are introduced to the invasive range. When biocontrol agents are released, they may self‐sort to perform best in their respective niches. We hypothesized that two biocontrol agents—Scotch broom seed beetle, Bruchidius villosus (Fabricius) (Coleoptera: Chrysomelidae) and Scotch broom seed weevil, Exapion fuscirostre (Fabricius) (Coleoptera: Brentidae)—that both feed on seeds of the invasive legume Scotch broom, Cytisus scoparius L. Link (Fabaceae), would be impacted differently by different weather conditions and plant traits, and would show different success rates at field sites with different conditions. We used a 5‐year study to reveal that the two biocontrol agents are not uniformly distributed in the field and that weather and plant factors influence their success. We confirmed that weather conditions of the previous year influenced biocontrol agent attack rate and found that weather patterns at a field site may predict the impact of each biocontrol agent. [ABSTRACT FROM AUTHOR]