摘要：
Phosphorus-solubilizing bacteria are widely studied for their ability to immobilize heavy metals and promote plant growth. However, previous studies have been focused on the effects of phosphate-solubilizing bacteria on phosphorus release and heavy metal immobilization, and there is a lack of research on the effects of phosphatesolubilizing bacteria on rhizosphere soil bacterial communities and metabolites. In this study, the effects of Klebsiella sp. M2 on wheat rhizosphere microbiome and metabolism were investigated as well as the impact of these changes on wheat absorption of Cd. The results showed that under Cd stress, strain M2 reduced (77.54 %) the content of Cd in culture medium and secreted metabolites involved in plant growth promotion, Cd resistance, and phosphorus solubilization. A pot experiment showed that compared with the control, strain M2 increased (14.3 %-35.9 %) the dry weight and reduced (33.3 %-66.7 %) the content of Cd in wheat grains, straw, and roots. Strain M2 increased the exchangeable Ca, Ca2-P and Fe-P contents, soil pH, and alkaline phosphatase activity and decreased the acid-extractable Cd content in rhizosphere soil. The increase in Ca concentration had a significant promoting effect on the pH in rhizosphere soil. Moreover, the relative abundances of key bacteria such as Ramlibacter, Microvirga, Pseudarthrobacter, Massilia, Streptomyces, and Paenibacillus increased. Additionally, strain M2 increased the contents of some substances in rhizosphere soil that play an important role in immobilizing Cd and solubilizing phosphorus as well as improving wheat tolerance to Cd. The results showed that inoculation with an exogenous phosphate-solubilizing bacterial strain can result in the activation of key functional bacteria and the regulation of metabolite production in wheat rhizosphere soil to immobilize heavy metals, which has broad potential in the remediation of wheat fields with high heavy metal levels.
摘要：
<jats:sec><jats:title>Background</jats:title><jats:p>Brassinosteroids (BRs) are a class of naturally occurring steroidal phytohormones mediating a wide range of pivotal developmental and physiological functions throughout the plant’s life cycle. Therefore, it is of great significance to determine the content and the distribution of BRs in plants.Regretfully, although a large number of quantitative methods for BRs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) have been reported, the <jats:italic>in planta</jats:italic> distribution of BRs is still unclear because of their lower contents in plant tissues and the lack of effective ionizable groups in their chemical structures.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We stablished a novel analytical method of BRs based on C18 cartridge solid-phase extraction (SPE) purification, 4-(dimethylamino)-phenylboronic acid (DMAPBA) derivatization, and online valve-switching system coupled with ultra-high performance liquid chromatography-electro spray ionization-triple quadrupole mass spectrometry (UHPLC-ESI-MS/MS). This method has been used to quantify three structural types of BRs (epibrassinolide, epicastasterone, and 6-deoxo-24-epicastaster one) in different organs of <jats:italic>Brassica napus</jats:italic> L. (rapeseed).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>We obtained the contents of three structural types of BRs in various organ tissues of rapeseed. The contents of three BRs in rapeseed flowers were the highest, followed by tender pods. The levels of three BRs all decreased during the maturation of the organs. We outlined the spatial distribution maps of three BRs in rapeseed based on these results, so as to understand the spatial distribution of BRs at the visual level.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Our results provided useful information for the precise <jats:italic>in situ</jats:italic> localization of BRs in plants and the metabolomic research of BRs in future work. The <jats:italic>in planta</jats:italic> spatial distribution of BRs at the visual level has been studied for the first time.</jats:p></jats:sec>
摘要：
Plant senescence is a highly coordinated process that is intricately regulated by numerous endogenous and environmental signals. The involvement of phytic acid in various cell signaling and plant processes has been recognized, but the specific roles of phytic acid metabolism in Arabidopsis leaf senescence remain unclear. Here, we demonstrate that in Arabidopsis thaliana the multiple inositol phosphate phosphatase (AtMINPP) gene, encoding an enzyme with phytase activity, plays a crucial role in regulating leaf senescence by coordinating the ethylene signal transduction pathway. Through overexpressing AtMINPP (AtMINPP-OE), we observed early leaf senescence and reduced chlorophyll contents. Conversely, a loss-of-function heterozygous mutant (atminpp/+) exhibited the opposite phenotype. Correspondingly, the expression of senescence-associated genes (SAGs) was significantly upregulated in AtMINPP-OE but markedly decreased in atminpp/+. Yeast one-hybrid and chromatin immunoprecipitation assays indicated that the EIN3 transcription factor directly binds to the promoter of AtMINPP. Genetic analysis further revealed that AtMINPP-OE could accelerate the senescence of ein3-1eil1-3 mutants. These findings elucidate the mechanism by which AtMINPP regulates ethylene-induced leaf senescence in Arabidopsis, providing insights into the genetic manipulation of leaf senescence and plant growth.
摘要：
In this study, the speciation, leachability, phytoaccessibility, and environmental risks of heavy metals (Cd, Zn, and Cu) during liquefaction of contaminated peanut straw in ethanol at different temperatures (220, 260, 300, 340, and 380 degrees C) were comprehensively investigated. The results showed that elevated temperatures facilitated heavy metal accumulation in the biochar. The acid-soluble/exchangeable and reducible fraction percentages of heavy metals were substantially reduced in the biochar after liquefaction as the temperature increased, and the oxidizable fraction became the dominant heavy metal fraction, accounting for 44.14-78.67%. Furthermore, although an excessively high liquefaction temperature (380 degrees C) increased the residual fraction percentages of Zn and Cu, it was detrimental to Cd immobilization. The acid-soluble/exchangeable Cd in the contaminated peanut straw readily migrates to the bio-oil during liquefaction, with the highest concentration of 1.60 mg/kg at 260 degrees C liquefaction temperature, whereas Zn and Cu are predominantly bound to the unexchangeable fraction in the bio-oil. Liquefaction inhibited heavy metal leachability and phytoaccessibility in biochar, the lowest extraction rates of Cd, Zn, and Cu were 0.71%, 1.66% and 0.95% by diethylenetriamine pentaacetic acid, respectively. However, the leaching and extraction concentrations increased when the temperature was raised to 380 degrees C. Additionally, heavy metal risk was reduced from medium and high risk to no and low risk. In summary, liquefaction reduces heavy metal toxicity and the risks associated with contaminated peanut straw, and a temperature range of 300-340 degrees C for ethanol liquefaction can be considered optimal for stabilizing heavy metals.
摘要：
Niga-ichigoside F1, an ursolic acid-type pentacyclic triterpenoid, possesses various pharmacological properties, including anti-tumor, anti-inflammatory, and antinociceptive potentials. However, its function and underlying mechanism in ulcerative colitis (UC) remain unknown. Hence, this study aimed to explore the effect of Nigaichigoside F1 on dextran sulfate sodium (DSS)-induced colitis. The predictive results of network pharmacology identified 311 common targets of Niga-ichigoside F1 and ulcerative colitis. The 4 highest-scoring genes were screened by the BottleNeck method and they were, signal transducer and activator of transcription 3 (STAT3), tumor necrosis factor (TNF), protein kinase B gamma (AKT3), and phosphatidylinositol-4,5bisphosphate 3-kinase, catalytic subunit beta (PIK3CB). KEGG pathway analysis indicated that Niga-ichigoside F1 probably exerted a protective effect on UC through the nuclear factor-kappa B (NF-kappa B) pathways. Molecular docking results showed that Niga-ichigoside F1 had a high affinity for nuclear factor-kappa B-inhibitor of nuclear factor-kappa B (NF-kappa B-I kappa B) complex, with the lowest binding energy. Furthermore, our results in vivo showed that Niga-ichigoside F1 alleviated weight loss, colon shortening, disease activity index (DAI), and histological scoring in DSS-induced colitis mice. Moreover, Niga-ichigoside F1 decreased the levels of inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and interleukin-8 (IL-8) and the expression of oxidative stress markers nitric oxide (NO), myeloperoxidase (MPO), and malonaldehyde (MDA) to mitigate inflammation and intestinal damage. Western blotting results evidenced that Nigaichigoside F1 intervention significantly regulated the NF-kappa B pathway. In conclusion, this study highlighted the potential of Niga-ichigoside F1 in ameliorating colitis, indicating its potential application as a functional food.
摘要：
Cis -13, 16-docosadienoic acid (DDA) is an omega -6 polyunsaturated fatty acid with great potential for application in medicine and health. Using microbial cell factories for DDA production is considered a viable alternative to extracting DDA from plant seeds. In this study, using Yarrowia lipolytica Po1f ( Delta ku70) as a chassis, firstly, the adaptation of three elongases in Po1f ( Delta ku70) were explored. Secondly, the DDA biosynthetic pathway was redesigned, resulting in a DDA content of 0.046 % of total fatty acids (TFAs). Thirdly, through the " push-pull " strategy, the DDA content increased to 0.078 % of TFAs. By enhancing the supply of acetyl-CoA, the DDA production in the engineered strain YL-7 reached 0.391 % of the TFAs (3.19 mg/L). Through optimizing the fermentation conditions, the DDA titer of YL-7 reached 29.34 mg/L. This research achieves the sustainable biological production of DDA in Y. lipolytica .
摘要：
With the rising morbidity of inflammatory bowel disease (IBD) year by year, conventional therapeutic drugs with systemic side effects are no longer able to meet the requirements of patients. Probiotics can improve gut microbiota, enhance intestinal barrier function, and regulate mucosal immunity, making them a potential complementary or alternative therapy for IBD. To compensate for the low potency of probiotics, genetic engineering technology has been widely used to improve their therapeutic function. In this review, we systematically summarize the genetically engineered probiotics used for IBD treatment, including probiotic chassis, genetic modification strategies, methods for controlling probiotics, and means of improving efficacy. Finally, we provide prospects on how genetically engineered probiotics can be extended to clinical applications.
通讯机构：
[Liu, G ] H;Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.
关键词：
Aquaculture wastewater;Immobilized bioreactor;Biochar;Nitrogen and phosphorus removal;Aquaculture wastewater;Denitrifying phosphorus-accumulating organism;Immobilized bioreactor;Biochar;Nitrogen and phosphorus removal
摘要：
Enterobacter cloacae G, a novel denitrifying phosphorus-accumulating bacterial strain, was isolated from anaerobic sludge tank of a wastewater treatment plant used for pig farms. It was discovered that a pH of 7, a temperature of 30degree celsius, an initial phosphorus concentration of 8 mg/L, and a C/N ratio of 10 were the strain's ideal growth conditions. To ensure the stability of strain G in wastewater treatment, strain G was immobilized by 5 % polyvinyl alcohol, 2 % sodium alginate, and 0.6 g of biochar and crosslinked for 9 h in 4 % calcium chloride saturated boric acid solution via an orthogonal test. After the immobilized microspheres were introduced into the sequencing batch reactor (SBR), the nitrate and phosphate removal rates achieved were 89.36 % and 65.53 %, respectively, with a hydraulic retention time (HRT) of 8 hours, a pH of 7.5, and a C/N ratio of 4.5. The immobilized microspheres containing strain G demonstrated potential for the treatment of nitrogen-rich and phosphorus-rich wastewater.
作者机构：
[Luo, Biao] College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, Hunan Province, 410128, China;[Luo, Biao] Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, 310021, China;[Zhang, Xianwen; Wang, Fang; Wang, Yan] Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, 310021, China;[Zhang, Xianwen] Key Laboratory of Traceability for Agricultural Genetically Modified Organisms, Ministry of Agriculture and Rural Affairs, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, 310021, China;[Wu, Wei] Shanghai YouLong Biotech Co., Ltd., Shanghai, 201114, China
通讯机构：
[Rao, Liqun; Wang, Qiming] C;College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, Hunan Province, 410128, China. Electronic address:
摘要：
Glyphosate resistance is a critically important trait for genetically modified (GM) crops. Mutation of the rice EPSPS gene results in a high level of glyphosate resistance, presenting significant potential for the development of glyphosate-tolerant crops. The resistance of rice to glyphosate is correlated with the expression levels of resistance genes. Therefore, developing a convenient, stable, and sensitive method for quantifying the OsmEPSPS protein is crucial for the development of glyphosate-resistant crops. We developed a double-antibody sandwich quantitative ELISA (DAS-ELISA) using a specific monoclonal antibody (mAb) for OsmEPSPS capture and an HRP-conjugated anti-OsmEPSPS rabbit polyclonal antibody (pAb). The method could be used to detect OsmEPSPS within a linear range of 16-256ng/mL with robust intra- and inter-batch duplicability (%CV values: 0.17%-7.24%). OsmEPSPS expression in the transgenic rice lines (54.44-445.80μg/g) was quantified using the DAS-ELISA. Furthermore, the expression of the OsmEPSPS gene was validated through Western blotting. This study demonstrated the reliability and stability of the DAS-ELISA for OsmEPSPS detection in GM rice.
摘要：
Axillary bud outgrowth, a key factor in ratoon rice yield formation, is regulated by several phytohormone signals. The regulatory mechanism of key genes underlying ratoon buds in response to phytohormones in ratoon rice has been less reported. In this study, GR24 (a strigolactone analogue) was used to analyze the ratooning characteristics in rice cultivar Huanghuazhan (HHZ). Results show that the elongation of the axillary buds in the first seasonal rice was significantly inhibited and the ratoon rate was reduced at most by up to 40% with GR24 treatment. Compared with the control, a significant reduction in the content of auxin and cytokinin in the second bud from the upper spike could be detected after GR24 treatment, especially 3 days after treatment. Transcriptome analysis suggested that there were at least 742 and 2877 differentially expressed genes (DEGs) within 6 h of GR24 treatment and 12 h of GR24 treatment, respectively. Further bioinformatics analysis revealed that GR24 treatment had a significant effect on the homeostasis and signal transduction of cytokinin and auxin. It is noteworthy that the gene expression levels of OsCKX1, OsCKX2, OsGH3.6, and OsGH3.8, which are involved in cytokinin or auxin metabolism, were enhanced by the 12 h GR24 treatment. Taken overall, this study showed the gene regulatory network of auxin and cytokinin homeostasis to be regulated by strigolactone in the axillary bud outgrowth of ratoon rice, which highlights the importance of these biological pathways in the regulation of axillary bud outgrowth in ratoon rice and would provide theoretical support for the molecular breeding of ratoon rice.
摘要：
Flowering time is an important improvement target in cotton breeding. The photoperiod is one of the significant factors affecting flowering in plant. Here, we conducted an exploration of how day length affects flowering and early maturating in upland cotton. After subjecting leaf samples of two cotton varieties, L19 (an early-maturity genotype) and L37 (a late-maturity genotype), to long-day (LD) and short-day (SD) conditions, we observed that the flowering time of both cotton varieties exhibited 7 - 11 days earlier under LD than SD. To investigate the underlying molecular mechanism, 8595 shared differentially expressed genes (DEGs) were identified in L19 and L37 based on transcriptome sequencing. Principal components analysis (PCA) showed the leaf stage and photoperiod treatment contributed the main differences between L19 and L37. KEGG analysis demonstrated that the DEGs were significantly enriched in circadian rhythms pathway and hormones signal transduction pathway, and the results of WGCNA further showed that green, darkgreen and lightgreen modules were significantly associated with day length. According to GO analysis, these DEGs in the three modules were involved in photoperiod related biological process such as rhythmic process, long-day photoperiodism and flowering process. A total of 75 hub genes were determined associated with each leaf developmental stage, and 8 genes were related to photoperiodic flowering pathway, including GhTOC1 , GhCCA1/LHY and GhFKF1 , etc. Finally, GhFKF1 , one of the hub genes, which highly expressed under long-day conditions, were selected for functional verification by virus induced gene silencing (VIGS). The results showed the flowering time of the silenced plants was delayed by 4.62 days. qPCR analysis indicated the expression of GhFKF1 in silenced plants was significantly reduced compared with the control and the expression levels of downstream genes GhFT and GhCO also decrease accordingly. Our research provides fresh insights into the molecular mechanisms of photoperiodic pathwaydepended flowering in cotton.
摘要：
Synergistic effect of dimethomorph (DIM) and pyrimethanil (PYM) was evaluated using the Wadley method and the molecular mechanism of the antifungal effects of the combined treatment was systematically investigated. DIM+PYM had a synergistic effect on Phytophthora capsici, with the synergistic effect being observed at 5:1, at which the synergy coefficient was 1.8536. The mycelia of the pathogen treated with DIM+PYM were branched, uneven in thickness, and swollen. Moreover, scanning electron microscopy (SEM) revealed that DIM+PYM caused mycelium breaks, swelling, and apex enlargement, while transmission electron microscopy (TEM) revealed structural damage, cavities, and cell membrane morphological abnormalities. DIM+PYM inhibited the growth of mycelia, destroyed the cell membrane, interfered with energy metabolism, reduced protein and sugar content. Additionally, the transcriptome and metabolome of fungi treated with DIM+PYM changed significantly; specifically, there were 1571 differentially expressed genes and 802 differential metabolites. DIM+PYM may mainly damage the cell membrane, energy, protein, soluble sugar pathways.
