Spatial chemistry of citrus reveals molecules bactericidal to Candidatus Liberibacter asiaticus.

Huanglongbing (HLB), associated with the psyllid-vectored phloem-limited bacterium, Candidatus Liberibacter asiaticus (CLas), is a disease threat to all citrus production worldwide. Currently, there are no sustainable curative or prophylactic treatments available. In this study, we utilized mass spectrometry (MS)-based metabolomics in combination with 3D molecular mapping to visualize complex chemistries within plant tissues to explore how these chemistries change in vivo in HLB-infected trees. We demonstrate how spatial information from molecular maps of branches and single leaves yields insight into the biology not accessible otherwise. In particular, we found evidence that flavonoid biosynthesis is disrupted in HLB-infected trees, and an increase in the polyamine, feruloylputrescine, is highly correlated with an increase in disease severity. Based on mechanistic details revealed by these molecular maps, followed by metabolic modeling, we formulated and tested the hypothesis that CLas infection either directly or indirectly converts the precursor compound, ferulic acid, to feruloylputrescine to suppress the antimicrobial effects of ferulic acid and biosynthetically downstream flavonoids. Using in vitro bioassays, we demonstrated that ferulic acid and bioflavonoids are indeed highly bactericidal to CLas, with the activity on par with a reference antibiotic, oxytetracycline, recently approved for HLB management. We propose these compounds should be evaluated as therapeutics alternatives to the antibiotics for HLB treatment. Overall, the utilized 3D metabolic mapping approach provides a promising methodological framework to identify pathogen-specific inhibitory compounds in planta for potential prophylactic or therapeutic applications.

Coordination between water relations strategy and carbon investment in leaf and stem in six fruit tree species.

The water relation strategy is a key issue in climate change. Given the difficulty of determining water relations strategy, there is a need for simple traits with a solid theoretical basis to estimate it. Traits associated with resource allocation patterns along a 'fast-slow' plant economics spectrum are particularly compelling, reflecting trade-offs between growth rate and carbon allocation. Avocado (Persea americana ), fig tree (Ficus carica ), mandarin (Citrus reticulata ), olive (Olea europaea ), pomegranate (Punica granatum ), and grapevine (Vitis vinifera ) were characterised in terms of iso-anisohydric strategy through stomatal behaviour, water potential at the turgor loss point (TLP), and hydroscape area. Additionally, the association of these metrics with leaf mass per area (LMA) and wood density (WDen) was explored. We observed high coordination between LMA and WDen, and both traits were related to metrics of water relation strategy. More anisohydric species tended to invest more carbon per unit leaf area or unit stem volume, which has implications for hydraulic efficiency and water stress tolerance. WDen and TLP were the most powerful traits in estimating the water relation strategy for six fruit species. These traits are easy to measure, time-cost efficient, and appear central to coordinating multiple traits and behaviours along the water relations strategies.

HPLC METHOD FOR THE QUANTIFICATION OF SOME ACTIVE FLAVONOIDS IN ETHYL ACETATE EXTRACT OF LEAVES OF BUTEA MONOSPERMA LINN.

AIM: The aim of the present investigation is to study HPLC process to evaluate Some Active Flavonoids in Ethyl Acetate Extract of Leaves of Butea monosperma Linn. MATERIAL AND METHODS: Using a soxhlation device, the leaves of Butea monosperma Linn. were extracted in stages. Each powdered batch (500g) was extracted in stages with polarity-graded solvents such as petroleum ether (Pet. Et) (60-80º), chloroform (CHCl3), ethyl acetate (EtOAc) using a soxhlet extractor. Alkaloids, flavonoids, glycosides, tannins, phenols, and steroids, among other chemical families of components, were identified through qualitative phytochemical screenings of each extract. To make a 10 g/ml stock, standard phenolic markers like quercetin, rutin, catechin, gallic acid, and chlorogenic acid were dissolved in methanol. Phytoconstituents were separated and identified from extracts using various solvents and combinations of solvents, which were chosen after consulting the literature. RESULTS AND DISCUSSION: Preliminary phytochemical screening showed the revealed that the leaves contain steroid, triterpenoids, fatty acid and alkaloids. While the ethyl acetate extract found to contain therapeutically important phytoconstitutes such as steroids, triterpenoids, saponins, flavonoids, and tannins. Bioactive extracts of Butea monosperma were found to include flavonoids and phenolic substances. In ethyl acetate extract, various flavonoids and phenolic compounds were discovered. CONCLUSION: This is a preliminary report on the identification of phytochemical and HPLC evaluation of ethyl acetate extract of leaves of Butea monosperma Linn. and to unravel the mechanisms driving bioactive qualities and the existence of putative synergy among these substances, more research is needed on the isolation and characterization of individual Flavonoids or phenolic compounds.

A meta-analysis of factors influencing the inactivation of Shiga toxin-producing Escherichia coli O157:H7 in leafy greens.

Recent advancements in modeling suggest that microbial inactivation in leafy greens follows a nonlinear pattern, rather than the simple first-order kinetics. In this study, we evaluated 17 inactivation models commonly used to describe microbial decline and established the conditions that govern microbial survival on leafy greens. Through a systematic review of 65 articles, we extracted 530 datasets to model the fate of Shiga toxin-producing Escherichia coli O157:H7 on leafy greens. Various factor analysis methods were employed to evaluate the impact of identified conditions on survival metrics. A two-parameter model (jm2) provided the best fit to most of both natural and antimicrobial-induced persistence datasets, whereas the one-parameter exponential model provided the best fit to less than 20% of the datasets. The jm2 model (adjusted R2 = .89) also outperformed the exponential model (adjusted R2 = .58) in fitting the pooled microbial survival data. In the context of survival metrics, the model averaging approach generated higher values than the exponential model for >4 log reduction times (LRTs), suggesting that the exponential model may be overpredicting inactivation at later time points. The random forest technique revealed that temperature and inoculum size were common factors determining inactivation in both natural and antimicrobial-induced die-offs.. The findings show the limitations of relying on the first-order survival metric of 1 LRT and considering nonlinear inactivation in produce safety decision-making.

Antifungal Potential and Mechanism of Bacillus velezensis HeN-7 Isolated from Tobacco Leaves on Bipolaris sorokiniana.

Wheat leaf blight caused by Bipolaris sorokiniana is a widespread fungal disease that poses a serious risk to wheat. Biological control without causing environmental pollution is one of the safest and most effective method to control plant diseases. The antagonistic bacterial strain HeN-7 (identified as Bacillus velezensis) was isolated from tobacco leaves cultivated in Henan province, China. The results of different concentrations of cell-free supernatant (CFS) from HeN-7 culture against B. sorokiniana mycelia showed that 20% HeN-7 CFS (v/v) reached the maximum inhibition rate of 96%. In the potted plants control assay, B. velezensis HeN-7 CFS exhibited remarkable biocontrol activity on the wheat infected with B. sorokiniana, the best pot control efficacy was 65% at 20% CFS. The research on the mechanism of action demonstrated that HeN-7 CFS induced the membrane lipid peroxidation in B. sorokiniana, leading to the disruption of cell membrane integrity and resulting in the leakage of cell contents; in addition, the intracellular mitochondrial membrane potential in mycelium dissipated and reactive oxygen species accumulated, thereby inhibiting the growth of B. sorokiniana. These results indicate that B. velezensis HeN-7 is a promising candidate as a biological control agent against Bipolaris sorokiniana infection.

Decline pattern and dietary risk assessment of spinetoram in grapes under Egyptian field conditions.

Spinetoram is one of the most extensively used insecticides globally and is a new spinosyn-based insecticide registered for direct treatment of Egyptian grapes. This work established and validated a developed method for determining spinetoram in grape berries and leaves using the QuEChERS coupled LC-MS/MS technique. The average recoveries ranged between 98.52-101.19% and 100.53-104.93%, with RSDs of 2.74-6.21% and 2.79-7.26% for grape berries and leaves, respectively. Spinetoram residues degraded in grape berries and leaves through a first-order kinetic, with an estimated half-life (t1/2) of 4.3 and 2.8 days in grape berries and leaves, respectively, and significant degradation (91.4-97.5%, respectively) after 14 days. Besides, the terminal residues of spinetoram detected in grape berries and leaves samples ranged between 0.017-0.077 mg‧kg-1 and 0.79-0.023 mg·kg-1, respectively, when applied two to three times at a single recommended rate, while it was varied between 0.026-0.44mg‧kg-1 and 0.79-0.023mg‧kg-1 when applied two to three times at a double recommended rate, respectively. A dietary risk assessment was conducted using scientific data from field trials, acceptable daily intake (ADI), and food consumption. It was determined that no noteworthy health hazards were connected to eating grape berries and leaves that had been treated with spinetoram since the risk quotients (RQs) were ≤ 0.4.

ACCELERATED CELL DEATH 6 is a crucial genetic factor shaping the natural diversity of age- and salicylic acid-induced leaf senescence in Arabidopsis.

Leaf senescence is a crucial process throughout evolution, vital for plant fitness as it facilitates the gradual shift of energy allocation between photosynthesis and catabolism overtime. This onset is influenced by a complex interplay of genetic and environmental factors, making senescence a key adaptation mechanism for plants in their natural habitats. Our study investigated the genetic mechanism underlying age-induced leaf senescence in Arabidopsis natural populations. Using a phenome high-throughput investigator, we comprehensively analyzed senescence responses across 234 Arabidopsis accessions and identified that environmental factors (e.g., ambient temperature) and physiological factors (e.g., defense responses) are substantially linked to senescence phenotypes. Through genome-wide association mapping, we identified the ACCELERATED CELL DEATH 6 (ACD6) locus as a potential regulator of senescence variation among natural accessions. Knocking out ACD6 in accessions with early and delayed senescence phenotypes resulted in varying degrees of delay in age-induced senescence, highlighting the accession-dependent regulatory role of ACD6 in leaf senescence. Furthermore, our findings suggest ACD6's involvement in senescence regulation via the salicylic acid signaling pathway. In summary, our study sheds light on the genetic regulation of leaf senescence in Arabidopsis natural populations, with the discovery of ACD6 as a potential candidate for genetic modification to enhance plant adaptation and survival.

Transcriptome, hormonal, and secondary metabolite changes in leaves of DEFENSE NO DEATH 1 (DND1) silenced potato plants.

DEFENSE NO DEATH 1 (DND1) is a cyclic nucleotide-gated ion channel protein. Earlier, it was shown that the silencing of DND1 in the potato (Solanum tuberosum L.) leads to resistance to late blight, powdery mildew, and gray mold diseases. At the same time, however, it can reduce plant growth and cause leaf necrosis. To obtain knowledge of the molecular events behind the pleiotropic effect of DND1 downregulation in the potato, metabolite and transcriptome analyses were performed on three DND1 silenced lines of the cultivar 'Désirée.' A massive increase in the salicylic acid content of leaves was detected. Concentrations of jasmonic acid and chlorogenic acid and their derivatives were also elevated. Expression of 1866 genes was altered in the same way in all three DND1 silenced lines, including those related to the synthesis of secondary metabolites. The activation of several alleles of leaf rust, late blight, and other disease resistance genes, as well as the induction of pathogenesis-related genes, was detected. WRKY and NAC transcription factor families were upregulated, whereas bHLHs were downregulated, indicating their central role in transcriptome changes. These results suggest that the maintenance of the constitutive defense state leads to the reduced growth of DND1 silenced potato plants.

Nymphaea alba leaf powder effectiveness in removing nisin from fermentation broth using docking and experimental analysis.

The accumulation of nisin in the fermentation medium can reduce the process's productivity. This research studied the potential of Nymphaea alba leaf powder (NALP) as a hydrophobic biosorbent for efficient in-situ nisin adsorption from the fermentation medium by docking and experimental analysis. Molecular docking analysis showed that di-galloyl ellagic acid, a phytochemical compound found in N. alba, had the highest affinity towards nisin. Enhancements in nisin adsorption were seen following pre-treatment of NAPL with HCl and MgCl2. A logistic growth model was employed to evaluate the growth dynamics of the biosorption capacity, offering valuable insights for process scalability. Furthermore, optimization through Response Surface Methodology elucidated optimal nisin desorption conditions by Liebig's law of the minimum, which posits that the scarcest resource governs production efficiency. Fourier Transform Infrared (FTIR) spectroscopy pinpointed vital functional groups involved in biosorption. Scanning electron microscopy revealed the changing physical characteristics of the biosorbent after exposure to nisin. The findings designate NALP as a feasible adsorbent for nisin removal from the fermentation broth, thus facilitating its application in the purification of other biotechnological products based on growth and production optimization principles.

Genome-wide epigenetic dynamics of tea leaves under mechanical wounding stress during oolong tea postharvest processing.

Understanding the epigenetic responses to mechanical wounding stress during the postharvest processing of oolong tea provides insight into the reprogramming of the tea genome and its impact on tea quality. Here, we characterized the 5mC DNA methylation and chromatin accessibility landscapes of tea leaves subjected to mechanical wounding stress during the postharvest processing of oolong tea. Analysis of the differentially methylated regions and preferentially accessible promoters revealed many overrepresented TF-binding motifs, highlighting sets of TFs that are likely important for the quality of oolong tea. Within these sets, we constructed a chromatin accessibility-mediated gene regulatory network specific to mechanical wounding stress. In combination with the results of the TF-centred yeast one-hybrid assay, we identified potential binding sites of CsMYC2 and constructed a gene regulatory network centred on CsMYC2, clarifying the potential regulatory role of CsMYC2 in the postharvest processing of oolong tea. Interestingly, highly accessible chromatin and hypomethylated cytosine were found to coexist in the promoter region of the indole biosynthesis gene (tryptophan synthase ß-subunit, CsTSB) under wounding stress, which indicates that these two important epigenetic regulatory mechanisms are jointly involved in regulating the synthesis of indole during the postharvest processing of oolong tea. These findings improve our understanding of the epigenetic regulatory mechanisms involved in quality formation during the postharvest processing of oolong tea.

Regulation of warming on the mixed decomposition of Artemisia ordosica and Leymus secalinus litter in Mu Us Desert, China is time-dependent.

Warming drives material cycling in terrestrial ecosystems by affecting litter decomposition, as it can alter litter yield, quality and decomposer composition and activity. The effect of warming on the decomposition of mixed litter in arid and semi-arid zones remains unknown. We investigated the mass loss and nutrient release dynamics during 450 days of decomposition of Artemisia ordosica, Leymus secalinus, and their mixture in Mu Us Desert by open-top chambers and litter bags. The results showed interspecific differences in the responses to warming, in that warming promoted mass loss and N and P release from L. secalinus and inhibited mass loss and P but promoting N release from A. ordosica. Mixing of A. ordosica and L. secalinus litter inhibited decomposition. Warming enhanced the antagonistic effects of mixed decomposition. The total mass loss of mixed litter was decreased by 9%, and the release of N and P was decreased by 4.9% and 12.6%, respectively. The antagonistic effects of mixed litter mass loss and P release under the warming treatment gradually strengthened with time, with N release changing from a synergistic to an antagonistic effect at 150 d. The non-additive effects produced by the mixed decomposition of A. ordosica and L. secalinus litter were jointly regulated by temperature and time. Future research on mixed litter decomposition should consider the interaction between temperature and time.

Relationship between tree species diversity and water holding capacity of litter layer in subtropical region.

Litter layer, serving as the "skin" of forest soil, plays a crucial role in conserving water resources and maintaining soil and water conservation. We analyzed the relationship of tree species richness, community weighted mean traits, and functional diversity with the standing mass, maximum water holding rate, and effective water sto-rage capacity of litters from various tree species including Liquidambar formosana, Mytilaria laosensis, Castanopsis sclerophylla, Castanopsis hystrix, Cunninghamia lanceolata, Pinus massoniana, Fokienia hodginsii, Taxus wallichiana and their combinations of mixed forests in subtropical region. The results showed that across various tree species combinations, the ranges of maximum water holding rate, standing litter mass and effective water storage capacity of undecomposed layer were 0-419%, 0-0.58 t·hm-2, and 0-1.66 t·hm-2, respectively. For the semi-decomposition layer, these values spanned in 0-375%, 0-6.14 t·hm-2, and 0-16.03 t·hm-2, respectively. Tree species richness and community weighted mean specific leaf area had significantly positive effects on standing mass of litter and effective water storage capacity, while community weighted mean leaf N content had significantly negative effect on standing mass of litter. The maximum water holding rate increased with the increases of functional diversity of specific leaf area and community weighted mean specific leaf area, decreased with the increase of community weighted mean leaf thickness. Results of structural equation model showed that tree species richness increased litter water holding capacity by increasing functional diversity of specific leaf area. The community weighted mean specific leaf area increased the water holding capacity of litter layer by increasing standing mass of litter and the maximum water holding rate. It is necessary to consider planting mixed forest with higher community weighted mean specific leaf area in the management of subtropical artificial forest, so as to improve the water holding capacity of litter layer.

Differential effects of polystyrene microplastics on the adsorption of cadmium and ciprofloxacin by tea leaf litter-derived magnetic biochar: Influencing factors and mechanisms.

Water pollution involves the coexistence of microplastics (MPs) and traditional pollutants, and how can MPs influence the adsorption of other pollutants by biochar during the treatment process remains unclear. This study aimed to investigate the influence of polystyrene microplastics (PS MPs) on the adsorption of cadmium (Cd) and ciprofloxacin (CIP) by magnetic biochar (MTBC) in the single and binary systems. MTBC was prepared using tea leaf litter; the effects of time, pH, and salt ions on the adsorption behaviors were investigated; and X-ray photoelectronic spectroscopy (XPS) and density flooding theory analysis were conducted to elucidate the influence mechanisms. Results indicated that PS MPs reduced the pollutants adsorption by MTBC due to the heterogeneous aggregation between PS MPs and MTBC and the surface charge change of MTBC induced by PS MPs. The effects of PS MPs on heavy metals and antibiotics adsorption were distinctly different. PS MPs reduced Cd adsorption on MTBC, which were significantly influenced by the solution pH and salt ions contents, suggesting the participation of electrostatic interaction and ion exchange in the adsorption, whereas the effects of PS MPs on CIP adsorption were inconspicuous. In the hybrid system, PS MPs reduced pollutants adsorption by MTBC with 66.3% decrease for Cd and 12.8% decrease for CIP, and the more remarkable reduction for Cd was due to the predominated physical adsorption, and CIP adsorption was mainly a stable chemisorption. The influence of PS MPs could be resulted from the interaction between PS MPs and MTBC with changing the functional groups and electrostatic potential of MTBC. This study demonstrated that when using biochar to decontaminate wastewater, it is imperative to consider the antagonistic action of MPs, especially for heavy metal removal. PRACTITIONER POINTS: Magnetic biochar (MTBC) was prepared successfully using tea leaf litter. MTBC could be used for cadmium (Cd) and ciprofloxacin (CIP) removal. Polystyrene microplastics (Ps MPs) reduced Cd/CIP adsorption by MTBC. Ps MPs effects on Cd adsorption were more obvious than that of CIP. Ps MPs changed the functional groups and electrostatic potential of MTBC, thus influencing MTBC adsorption.

[Relationships between functional traits and litterfall nutrient return characteristics across 21 tree species in subtropical plantations]. / 亚热带21ä¸ªæ ‘ç§äººå·¥æž—åŠŸèƒ½æ€§çŠ¶ä¸Žå‡‹è½ç‰©å »åˆ†å½’è¿˜ç‰¹å¾çš„å ³ç³».

The contribution of litterfall nutrient return to the maintenance of soil carbon pool and nutrient cycling is a crucial aspect of forest ecosystem functioning. Taking 21 tree species in subtropical young plantations as subjects, we investigated the correlation between litterfall nutrient return characteristics and functional traits of leaf and root and. The results showed notable variations in litterfall production, standing crop, and nutrient return across all the examined tree species. Mytilaria laosensis exhibited the highest litterfall production (689.2 g·m-2·a-1) and standing crop (605.1 g·m-2), while Cryptomeria fortunei demonstrated the lowest litterfall production (36.0 g·m-2·a-1) and standing crop (10.0 g·m-2). The nitrogen and phosphorus return amounts of 21 species ranged from 3.0 to 48.3 kg·hm-2 and from 0.1 to 2.0 kg·hm-2, respectively. Castanopsis fissa demonstrated the highest nitrogen return, while Liquidambar formosana exhibited the highest phosphorus return. C. fortunei had the lowest nitrogen and phosphorus return. Results of the stepwise regression analysis indicated that litterfall production exhibited a significant negative correlation with leaf nitrogen content and leaf dry matter content, and a significant positive correlation with fine root tissue density. Additionally, leaf nitrogen content, leaf dry matter content, and specific root length had a significant negative impact on standing crop. The structural equation modelling results indicated that leaf dry matter content had a direct or indirect negative effect on nitrogen return amount through the reduction of litterfall production. Conversely, fine root tissue density had a significant positive impact on nitrogen return amount by increasing litter leaf nitrogen content. Both leaf nitrogen content and leaf dry matter content had direct or indirect negative effects on phosphorus return amount through the reduction of litterfall production. In conclusion, the tree species with low leaf nitrogen content and dry matter content, as well as high fine root tissue density, was recommended for the establishment of plantations in the subtropical zone in order to enhance nutrient cycling through litter decomposition and improve soil fertility and forest productivity.

[Multidimensional biodiversity of subalpine forest communities on the eastern edge of the Qinghai-Tibet Plateau, China]. / é’è—é«˜åŽŸä¸œç¼˜äºšé«˜å±±æ£®æž—ç¾¤è½çš„å¤šç»´åº¦ç”Ÿç‰©å¤šæ ·æ€§.

We analyzed multidimensional biodiversity (including species diversity, functional diversity, and phylogenetic diversity) of needle-broadleaf mixed forests of Abies fargesii var. faxoniana-Betula spp. and needleleaf forests of A. fargesii var. faxoniana in the subalpine regions of eastern edge of Qinghai-Tibet Plateau. We measured leaf functional traits including leaf area, leaf thickness, leaf dry matter content, and specific leaf area. The results showed that leaf thickness (0.28 mm) and leaf dry matter content (319.86 mg·g-1) in the needle-broadleaf mixed forests were significantly lower than in the needleleaf forest (0.39 mm and 371.33 mg·g-1, respectively), while specific leaf area (192.74 cm2·g-1) was significantly higher (100.91 cm2·g-1). Leaf area showed no significant difference between the two forest communities (27.88 and 26.63 cm2, respectively). The phylogenetic signals of all leaf functional traits were significant, except for leaf thickness. The phylogenetic structure of the needle-broadleaf mixed forests and needleleaf forest communities tended toward divergence. Shannon diversity index, Simpson diversity index, species richness, functional richness, functional dispersion, Rao's quadratic entropy, and phylogenetic diversity in the needle-broadleaf mixed forests were all significantly higher than in the needleleaf forest, and these indices were significantly positively correlated. Competitive exclusion played a major role in the assembly of subalpine forest communities, and species diversity, functional diversity, and phylogenetic diversity exhibited synchrony.

[Effects of exogenous 6-BA on flag leaf physiology, yield, and quality of wheat after low temperature stress at booting stage]. / 外源6-BA对孕穗期低温胁迫后小麦旗叶生理、产量及品质的影响.

Low temperature (LT) in spring usually occurs at the booting of winter wheat, resulting in reduction of wheat yield. In this study, we used the LT-sensitive wheat cultivar 'Wanmai 52' and the LT-insensitive wheat cultivar 'Yannong 19' as experimental materials to conduct LT treatment (-2 ℃ and 0 ℃) at booting stage. After the LT treatment, we sprayed 6-benzylaminoadenine (6-BA) solutions with concentrations of 10, 20, and 30 mg·L-1 respectively, with equal mass distilled water as control to investigate the effects of spraying 6-BA on the physiological characteristics, yield and quality of wheat flag leaves after LT stress at booting stage. The results showed that compared with the control, young ear of wheat treated with exogenous spraying 6-BA was fuller, the floret morphology was improved, and the number of vascular bundles under the spike was increased. 6-BA application promoted the accumulation of soluble sugar, soluble protein, and proline in flag leaves. The activities of peroxidase and superoxide dismutase were increased, and the content of malondialdehyde was decreased. Exogenous 6-BA application decreased the number of degenerated spikes of wheat, increased the number of grains per spike and 1000-grain weight, as well as the contents of grain protein, wet gluten, and sedimentation value. In summary, exogenous 6-BA application could effectively alleviate the effects of LT stress on flag leaf and yield of wheat. Under the conditions of this experiment, the mitigation effect of spraying 6-BA solution on Yannong 19 was higher than that of Wanmai 52, and the mitigation effect of spraying 20 mg·L-1 6-BA solution on low temperature stress was the best.

Enzymatic synthesis of Hydroxytyrosol from Oleuropein for valorization of an agricultural waste.

Oleuropein (OP) is an appreciated compound present not only in fruits but also in leaves of olive trees, which can be transformed into hydroxytyrosol (HT), a substance with high antioxidant activity. In this work, the transformation of an agricultural residue containing OP (olive leaves or wastewater from mills) to the high added value compound HT is accomplished through different enzymatic strategies. Different enzymes were used, immobilized on various supports by diverse binding forces: beta-glucosidase encapsulated in siliceous material, esterases and lipases immobilized on hydrophobic supports (octyl-functionalized amorphous silica and periodic mesoporous organosilica), and esterase immobilized on amine-functionalized ordered mesoporous silica. All these biocatalysts were tested for oleuropein hydrolysis through two different reaction approaches: a) split of glucosidic bond catalyzed by beta-glucosidase (ß-glu), followed by hydrolysis of the aglycon and further ester hydrolysis. 5 mg·mL-1 of ß-glu fully hydrolyzed 5 mM OP at pH 7 and 50°C in 7 days, and further enzymatic hydrolysis of the aglycon yielded near to 0.5 mM HT in the best conditions tested. b) via direct hydrolysis of the ester bond to produce hydroxytyrosol in a one-step reaction using esterases or lipases. The latter reaction pathway catalyzed by lipase from Penicillium camemberti immobilized on octyl-silica (4 mg·mL-1) at 35°C and pH 6 directly produced 6.8 mM HT (1 mg·mL-1), transforming in 12 days near to 30% of the initial 25 mM OP from a commercial olive leaves extract.

Kondoa tianchiensis f.a., sp. nov., an anamorphic yeast species isolated from plant leaves.

Two yeast strains, NYNU 236122 and NYNU 236180, were isolated from plant leaves collected in Tianchi Mountain, Henan Province, central China. Molecular phylogenetic analyses revealed the closest relatives of the strains are three described Kondoa species, Kondoa chamaenerii, Kondoa miscanthi, and Kondoa subrosea. Genetically, the isolated strains differed from the type strains of their three related species by 2-11(0.2-1.8%) base substitutions in the D1/D2 domain, 16-40 (2.6-5.6%) base mismatches in the internal transcribed spacer region, and more than 10.1% base substitutions in the partial RPB2 gene. Furthermore, the two strains differ physiologically from their closest related species, K. chamaenerii, in their ability to assimilate dl-lactate, nitrite, and l-lysine and their inability to assimilate nitrate. Additionally, they differ from K. miscanthi and K. subrosea in their ability to assimilate inulin, d-gluconate, and l-lysine. The species name of Kondoa tianchiensis f.a., sp. nov. is proposed with holotype CICC 33616T (Mycobank MB 853544).

Unveiling the total catechin profile in tea leaves: a novel one-step extraction method empowered by UPLC-IDX-Orbitrap mass spectrometry.

More catechins are found in green tea than in any other type of tea, with its predominant production taking place in Asian nations. Consumption of green tea has been strongly correlated with a reduced risk of many diseases. This study introduces a new, efficient, and reliable method for extracting total catechins using ultra-high-performance liquid chromatography coupled with an ID-X-Orbitrap Mass spectrometer (UHPLC-IDX-Orbitrap-MS). The method was then applied to quantify the catechin content in green tea, yielding results comparable to previously published studies. Among the various sources of green tea analyzed, the lowest average catechin content was observed in Vietnam, Japan (2: Matcha), and Morocco, ranging between 346 and 322 mg/L. Conversely, the highest average catechin content (between 424 and 422 mg/L) was found in Sri Lanka and Japan (1: Sencha). For the remaining green tea extracts, the catechin levels ranged from 367 to 410 mg/L, exhibiting similar values. These findings demonstrate the high reproducibility of the proposed extraction procedure, with a relative standard deviation (RSD) error of less than 15% for the catechin standard. Additionally, the limit of detection for catechins was determined to be 1 ng mL-1. This study serves as a pilot investigation for extracting catechins from various green tea sources. Future research will focus on identifying all active compounds present. Furthermore, it is worth noting that this study aligns with the goals set forth in Saudi Vision 2030, which aims to diversify the country's economy and promote scientific advancements in various fields, including healthcare and agriculture.

Influence of spray volume on the control of Conyza spp. in soybean pre-sowing with burndown.

The herbicide mixture diclosulam + halauxifen appears to be an alternative for the control of Conyza spp.; however, the spray volume may result in different spray deposition effects on the target and, therefore, on the control. Therefore, the objective of this study was to evaluate the impact of different spray volumes of diclosulam + halauxifen on the control of and damage to the leaf surface of Conyza spp. The experiment was conducted in the field in a randomized block design with four replications. Diclosulam + halauxifen (23.52 g ai ha-1 + 6.32 g ae ha-1) was applied to Conyza spp. at average heights greater than 10 cm, followed by sequential application of glufosinate ammonium (500 g ai ha-1) after 14 days. Different spray volumes (200, 150, 100, 80 and 50 L ha-1) were used. The percentage of droplet coverage was evaluated using hydrosensitive paper and analyzed using DropScan software. After 24 hours of initial application, the leaves were collected for scanning electron microscopy (SEM). Although the different spray volumes did not affect the control, faster necrosis effects were observed at 150 and 200 L ha-1. Moreover, the trichome and stomatal density decreased at a spray volume of 200 L ha-1, indicating greater initial damage at this spray volume. Thus, increased spray spray volumes result in increased spray spray deposition, damage to leaf structures and consequently increased control speed.