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The New Phytologist Jun 2024
PubMed: 38890807
DOI: 10.1111/nph.19915 -
The New Phytologist Jun 2024Secondary xylem and phloem originate from a lateral meristem called the vascular cambium that consists of one to several layers of meristematic cells. Recent lineage... (Review)
Review
Secondary xylem and phloem originate from a lateral meristem called the vascular cambium that consists of one to several layers of meristematic cells. Recent lineage tracing studies have shown that only one of the cambial cells in each radial cell file functions as the stem cell, capable of producing both secondary xylem and phloem. Here, we first review how phytohormones and signalling peptides regulate vascular cambium formation and activity. We then propose how the stem cell concept, familiar from apical meristems, could be applied to cambium studies. Finally, we discuss how this concept could set the basis for future research.
PubMed: 38890801
DOI: 10.1111/nph.19897 -
The New Phytologist Jun 2024
PubMed: 38887143
DOI: 10.1111/nph.19910 -
The New Phytologist Jun 2024Bamboo, a renewable resource with rapid growth and an impressive height-to-diameter ratio, faces mechanical instability due to its slender structure. Despite this,...
Bamboo, a renewable resource with rapid growth and an impressive height-to-diameter ratio, faces mechanical instability due to its slender structure. Despite this, bamboo maintains its posture without breaking in its battle against environmental and gravitational forces. But what drives this motor function in bamboo? This study subjected Moso bamboo (Phyllostachys edulis) to gravitational stimulation, compelling it to grow at a 45° angle instead of upright. Remarkably, the artificially inclined bamboo exhibited astonishing shape control and adjustment capabilities. The growth strain was detected at both macroscopic and microscopic levels, providing evidence for the presence of internal stress, namely growth stress. The high longitudinal tensile stress on the upper side, along with a significant asymmetry in stress distribution in tilted bamboo, plays a pivotal role in maintaining its mechanical stability. Drawing upon experimental findings, it can be deduced that the growth stress primarily originates from the broad layers of fiber cells. Bamboo could potentially regulate the magnitude of growth stress by modifying the number of fiber cell layers during its maturation process. Additionally, the microfibril angle and lignin disposition may decisively influence the generation of growth stress.
PubMed: 38887135
DOI: 10.1111/nph.19913 -
International Journal of Systematic and... Jun 2024Strain I65 (=KACC 22647=JCM 35315), a novel Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, rod-shaped, and orange-pigmented bacterium was isolated...
Strain I65 (=KACC 22647=JCM 35315), a novel Gram-stain-negative, strictly aerobic, non-motile, non-spore-forming, rod-shaped, and orange-pigmented bacterium was isolated from influent water of a wastewater treatment system after treatment with several antibiotics, such as meropenem, gentamicin, and macrolide. The newly identified bacterial strain I65 exhibits significant multi-drug and heavy metal resistance characteristics. Strain I65 was grown in Reasoner's 2A medium [0 %-2 % (w/v) NaCl (optimum, 0 %), pH 5.0-10.0 (optimum, pH 7.0), and 20-45°C (optimum, 30 °C)]. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that strain I65 was closely related to CCBAU 05354 (99.56 % sequence similarity), THG-DN5.5 (97.51 %), and GR10-1 (97.09 %). Further analysis of the whole-genome sequence confirmed that the digital DNA-DNA hybridization, average nucleotide identity, and average amino acid identity values between strain I65 and CCBAU 05354 were 23.4, 80.7, and 85.0 %, respectively, suggesting that strain I65 is distinct from . The genome size of strain I65 was 6.1 Mbp, as assessed using the Oxford Nanopore platform, and its genomic DNA G+C content was 43.0 mol%. The major fatty acids of strain I65 were iso-C and iso-C G, and the major respiratory quinone was MK-7. Moreover, the major polar lipid of strain I65 was phosphatidylethanolamine. Based on genotypic, chemotaxonomic, and phenotype data, strain I65 represents a novel species belonging to the genus , for which the name sp. nov. is proposed. The type strain is I65 (=KACC 22647=JCM 35315).
Topics: Wastewater; RNA, Ribosomal, 16S; Phylogeny; DNA, Bacterial; Fatty Acids; Bacterial Typing Techniques; Base Composition; Sequence Analysis, DNA; Nucleic Acid Hybridization; Flavobacteriaceae; Anti-Bacterial Agents; Vitamin K 2; Phospholipids; Water Microbiology; Whole Genome Sequencing
PubMed: 38885037
DOI: 10.1099/ijsem.0.006425 -
International Journal of Systematic and... Jun 2024A Gram-stain-negative, orange-yellow, rod-shaped bacterium, designated strain SCSIO 19198, was isolated from sediment of the Haima cold seep in the South China Sea, PR...
A Gram-stain-negative, orange-yellow, rod-shaped bacterium, designated strain SCSIO 19198, was isolated from sediment of the Haima cold seep in the South China Sea, PR China. The strain was aerobic and non-motile. Growth of strain SCSIO 19198 occurred at pH 7-9 (optimum, pH 7), 15-37 °C (optimum, 25-32 °C) and with 3-8 % (w/v) NaCl (optimum, 3-6 % NaCl). Phylogenetic analyses based on 16S rRNA sequences revealed that strain SCSIO 19198 belonged to the genus , having the highest similarity to HD-3 (98.35 %), followed by KYW589 (95.17 %) and GYP-24 (94.89 %). The DNA G+C content was 35.92 mol%. The average nucleotide identity value between the genome of strain SCSIO 19198 and that of HD-3 was 88.49 %. The digital DNA-DNA hybridization value between strain SCSIO 19198 and HD-3 was 36 %. The major fatty acids (>10 %) of strain SCSIO 19198 were iso-C, iso-C G, summed feature 3 (C 6/C ω7) and anteiso-C. MK-6 was the only detected respiratory quinone. The polar lipids of strain SCSIO 19198 included phosphatidylethanolamine, two aminolipids, glycolipid and two unidentified lipids. The phenotypic, phylogenetic, chemotaxonomic and genomic data clearly suggest that strain SCSIO 19198 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is SCSIO 19198 (=MCCC 1K08674=KCTC 102078).
Topics: RNA, Ribosomal, 16S; China; Phylogeny; Fatty Acids; Base Composition; DNA, Bacterial; Bacterial Typing Techniques; Nucleic Acid Hybridization; Geologic Sediments; Sequence Analysis, DNA; Seawater; Vitamin K 2; Molecular Sequence Data
PubMed: 38885036
DOI: 10.1099/ijsem.0.006428 -
Journal of Ethnopharmacology Jun 2024The bark of Canarium schweinfurthii is used in ethnomedicine for the treatment of diabetes, pain, malaria, fever and diarrhoea.
ETHNOPHARMACOLOGICAL RELEVANCE
The bark of Canarium schweinfurthii is used in ethnomedicine for the treatment of diabetes, pain, malaria, fever and diarrhoea.
AIM OF THE STUDY
The chemical phytoconstituents, antidiarrheal, anti-inflammatory and antinociceptive effects and safety profile of the aqueous extract of Canarium schweinfurthii bark (AECSB) were investigated.
MATERIALS AND METHODS
Gas chromatography-mass spectrometry (GC-MS) was used to analyse the phytochemical composition. In the acute toxicity test, AECSB were administered up to 2 g/kg by oral gavage. For the subacute toxicity test (28 days), rats in group 1 (control) received no AECSB, while rats in groups 2-4 were administered different doses of AECSB. Charcoal meal transit and castor oil-induced diarrhoea models were used to study the antidiarrheal effect, while egg albumin/carrageenan and acetic acid/tail immersion models were used for the anti-inflammatory and antinociceptive studies, respectively. With the exception of the acute toxicity experiment, AECSB was administered orally at doses of 200, 400 and 800 mg/kg.
RESULTS
Bioactive phytoconstituents identified include p-cymene, δ-terpinene, linalool and phytol. No adverse effects or mortality were observed in acute and subacute studies. Treatment with AECSB (28 days) had no significant effect on organ weight, biochemical, hematologic and histopathologic parameters compared to the control groups (p > 0.05). Comparable antidiarrheal and antinociceptive effects were observed in both AECSB- and standard drug-treated groups, while the 400 and 800 mg/kg AECSB-treated groups showed remarkable anti-inflammatory effects compared to the standard drug-treated and control groups (p < 0.05).
CONCLUSION
AECSB has antidiarrheal, antinociceptive and anti-inflammatory effects and can be safely used for therapeutic purposes.
PubMed: 38878840
DOI: 10.1016/j.jep.2024.118460 -
The New Phytologist Jun 2024Bacterial pathogens inject effector proteins inside plant cells to manipulate cellular functions and achieve a successful infection. The soil-borne pathogen Ralstonia...
Bacterial pathogens inject effector proteins inside plant cells to manipulate cellular functions and achieve a successful infection. The soil-borne pathogen Ralstonia solanacearum (Smith), the causal agent of bacterial wilt disease, secretes > 70 different effectors inside plant cells, although only a handful of them have been thoroughly characterized. One of these effectors, named RipI, is required for full R. solanacearum pathogenicity. RipI associates with plant glutamate decarboxylases (GADs) to promote the accumulation of gamma-aminobutyric acid (GABA), which serves as bacterial nutrient. In this work, we found that RipI can also suppress plant immune responses to bacterial elicitors, which seems to be unrelated to the ability of RipI to induce GABA accumulation and plant cell death. A detailed characterization of the RipI features that contribute to its virulence activities identified two residues at the C-terminal domain that mediate RipI interaction with plant GADs and the subsequent promotion of GABA accumulation. These residues are also required for the appropriate homeostasis of RipI in plant cells and the induction of cell death, although they are partially dispensable for the suppression of plant immune responses. Altogether, we decipher and uncouple the virulence activities of an important bacterial effector at the biochemical level.
PubMed: 38877712
DOI: 10.1111/nph.19899 -
The New Phytologist Jun 2024Tree peony (Paeonia suffruticosa) undergoes bud endodormancy, and gibberellin (GA) pathway plays a crucial role in dormancy regulation. Recently, a key DELLA protein...
Tree peony (Paeonia suffruticosa) undergoes bud endodormancy, and gibberellin (GA) pathway plays a crucial role in dormancy regulation. Recently, a key DELLA protein PsRGL1 has been identified as a negative regulator of bud dormancy release. However, the mechanism of GA signal to break bud dormancy remains unknown. In this study, yeast two-hybrid screened PsSOC1 interacting with PsRGL1 through its MADS domain, and interaction was identified using pull-down and luciferase complementation imaging assays Transformation in tree peony and hybrid poplar confirmed that PsSOC1 facilitated bud dormancy release. Transcriptome analysis of PsSOC1-overexpressed buds indicated PsCYCD3.3 and PsEBB3 were its potential downstream targets combining with promoter survey, and they also accelerated bud dormancy release verified by genetic analysis. Yeast one-hybrid, electrophoretic mobility shifts assays, chromatin immunoprecipitation quantitative PCR, and dual luciferase assays confirmed that PsSOC1 could directly bind to the CArG motif of PsCYCD3.3 and PsEBB3 promoters via its MADS domain. PsRGL1-PsSOC1 interaction inhibited the DNA-binding activity of PsSOC1. Additionally, PsCYCD3.3 promoted bud dormancy release by rebooting cell proliferation. These findings elucidated a novel GA pathway, GA-PsRGL1-PsSOC1-PsCYCDs, which expanded our understanding of the GA pathway in bud dormancy release.
PubMed: 38877710
DOI: 10.1111/nph.19893 -
The New Phytologist Jun 2024Leaf decomposition varies widely across temperate forests, shaped by factors like litter quality, climate, soil properties, and decomposers, but forest heterogeneity may...
Leaf decomposition varies widely across temperate forests, shaped by factors like litter quality, climate, soil properties, and decomposers, but forest heterogeneity may mask local tree influences on decomposition and litter-associated microbiomes. We used a 24-yr-old common garden forest to quantify local soil conditioning impacts on decomposition and litter microbiology. We introduced leaf litter bags from 10 tree species (5 arbuscular mycorrhizal; 5 ectomycorrhizal) to soil plots conditioned by all 10 species in a full-factorial design. After 6 months, we assessed litter mass loss, C/N content, and bacterial and fungal composition. We hypothesized that (1) decomposition and litter-associated microbiome composition would be primarily shaped by the mycorrhizal type of litter-producing trees, but (2) modified significantly by underlying soil, based on mycorrhizal type of the conditioning trees. Decomposition and, to a lesser extent, litter-associated microbiome composition, were primarily influenced by the mycorrhizal type of litter-producing trees. Interestingly, however, underlying soils had a significant secondary influence, driven mainly by tree species, not mycorrhizal type. This secondary influence was strongest under trees from the Pinaceae. Temperate trees can locally influence underlying soil to alter decomposition and litter-associated microbiology. Understanding the strength of this effect will help predict biogeochemical responses to forest compositional change.
PubMed: 38877705
DOI: 10.1111/nph.19900