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Abscisic acid (ABA) plays multiple and pivotal roles in plant defence against abiotic and biotic stresses. Blackleg, mainly caused by the fungal pathogen Leptosphaeria maculans, is one of the most devastating diseases in canola (Brassica napus) resulting in significant yield loss worldwide. Few studies have investigated the function of ABA biosynthesis genes in response to fungal pathogens. In this study, we identified and characterized BnNCED3 (9‐cis‐epoxycarotenoid dioxygenease) and BnTX1 (trithorax‐like factor) from B. napus. Transgenic B. napus ‘Westar’ plants overexpressing BnNCED3 showed enhanced adult plant resistance to blackleg infection. Chromatin immunoprecipitation‐quantitative PCR demonstrated that BnTX1 bound to the promoter region of the BnNCED3 gene. However, the overexpression of BnTX1 in transgenic plants decreased adult plant resistance to blackleg pathogen infection. The expression analysis confirmed the abundance of BnNCED3 transcripts was higher in BnTX1‐RNAi knockdown plants than in overexpressing plants. Thus, BnTX1 might play a negative role in regulating BnNCED3 gene expression and hence ABA biosynthesis, thereby affecting plant disease resistance. Our study provides a new model demonstrating how increased ABA levels can enhance plant disease resistance, which may lead to the characterization of minor/quantitative genes in the B. napus–L. maculans interaction. [ABSTRACT FROM AUTHOR]

Leptosphaeria maculans is a fungal pathogen that causes blackleg disease in canola (Brassica napus), resulting in significant yield and economic losses in Canada and many parts of the world. Plant NAC transcription factors play critical roles in plant development and response to biotic or abiotic stress. In this study, we identified and characterized a BnNAC19 gene from Brassica napus. The overexpression of BnNAC19 in transgenic canola plants contributed to the improvement of seedling resistance against L. maculans. The mycelial growth of a green fluorescent protein‐tagged strain of L. maculans and production of pycnidiospores were shown to be inhibited in the transgenic canola plants overexpressing BnNAC19. In addition, the canola transgenic line overexpressing BnNAC19 showed increased disease resistance in the adult plant, which was determined by quantitative resistance. Both increased seedling and adult plant resistance in transgenic canola plants overexpressing BnNAC19 indicate that the BnNAC19 gene plays a positive role against L. maculans. The expression pattern of genes BnNAC19 upstream and downstream of BnNAC19 that participate in plant defence pathways were investigated to elucidate the B. napus resistance mechanisms to L. maculans infection, and hence to aid the long‐term blackleg disease‐resistant breeding programmes. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-density ionic active centers (2.014–4.883 mmol g-1) and hydrogen-bond donors (HBDs) were integrated into diamide-linked PIMDILs (PMAIL-x and PBAIL-2) catalysts successfully. • The interfacial synergistic effects between the diamide HBDs and high-density ionic active centers promotes the CO 2 conversion under ambient pressure. • The formation of hydrogen bonds at the catalytic reaction interface can effectively activate CO 2 and epoxides substrates. • PMAIL-2 possesses the highest catalytic activity, which can convert various epoxides into cyclic carbonates in excellent yields and selectivity (>99 %). The ionic active centers and hydrogen-bond donors (HBDs) in heterogeneous catalytic materials are highly beneficial for enhancing the interaction between solid–liquid-gas three-phase interfaces and promoting effective fixation of carbon dioxide (CO 2). Diamide-linked imidazolyl poly(dicationic ionic liquid)s catalysts PIMDILs (PMAIL-x and PBAIL-2) were synthesized through the copolymerization of diamide-linked imidazolyl dicationic ionic liquids (IMDILs) with divinylbenzene (DVB), which successfully enable the simultaneous construction of high-density and uniformly distributed ionic active centers (2.014–4.883 mmol g−1) and hydrogen-bond donors (HBDs). The as-synthesized PIMDILs present excellent catalytic activity in promoting the cycloaddition of CO 2 with epoxides. PMAIL-2 could convert epichlorohydrin (ECH) with a quantitative conversion of 99.8 % (selectivity > 99 %) under ambient pressure. Furthermore, only a decrease in activity of 5 % was observed even after six cycles of recycling. The excellent conversions (>97.3 %) were achieved for various terminal substituted epoxides. The experimental and characterization results reveal that the high-density ionic active centers and amide HBDs can effectively activate the reaction substrates, their synergistic effect plays a crucial role at the catalyst interface. This work is expected to provide some useful insights for the rational construction of heterogeneous catalysts for CO 2 conversion. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • BiOCl with reactive {0 0 1} exposed facets were obtained by hydrothermal method. • Solution pH and dulcitol played the major role in the synthesis of facets. • Enriched oxygen vacancies reduced the carrier recombination pathways. • Superoxide radical was the dominant active species in the degradation pathways. Abstract The 2D BiOCl nanosheets with excellent photocatalytic activity were synthesized via the facile hydrothermal method by regulating the pH value of the precursor solution and using dulcitol (C 6 H 14 O 6) as the surfactant. The photocatalysts were characterized by XRD, FT-IR, SEM, TEM, BET, XPS, ESR, O 2 -TPD, EIS, DRS and PL. The results of morphological and structural characterization indicate that the pH has a large effect on the thickness of the nanosheets and the exposure ratio of {0 0 1} facets. The photocatalytic property of the sample prepared at pH 4 showed excellent visible-light photocatalytic performance to degrade RhB owing to the small thickness, the exposed {0 0 1} facets and the optimum concentration of oxygen vacancy. Moreover, the reasonable photocatalytic mechanism was revealed by the active species trapping experiments and ESR characterization, which suggested O 2 − and h+ are the main active species in the present system. [ABSTRACT FROM AUTHOR]

Abstract: Leptosphaeria maculans causes blackleg disease on Brassica napus, an economically important oilseed crop. Brassica juncea has high resistance to blackleg and is a source for the development of resistant B. napus varieties. To transfer the Rlm6 resistance gene from B. juncea into B. napus, an interspecific cross between B. napus “Topas DH16516” and B. juncea “Forge” was produced, followed by the development of F2 and F3 generations. Sequence characterized amplified region (SCAR) and cleaved amplified polymorphic sequence (CAPS) markers linked to the L. maculans resistance gene Rlm6 were developed. Segregation of SCAR and CAPS markers linked to Rlm6 were confirmed by genotyping of F2 and F3 progeny. Segregation of CAPS markers and phenotypes for blackleg disease severity in F2 plants had a Mendelian ratio of 3:1 in resistant vs. susceptible plants, respectively, supporting the assumption that genetic control of resistance was by a single dominant gene. The molecular markers developed in this study, which show linkage with the L. maculans resistance gene Rlm6, would facilitate marker‐assisted backcross breeding in a variety development programme. [ABSTRACT FROM AUTHOR]

Abstract: Leptosphaeria maculans is the most important fungal pathogen of canola (Brassica napus, oilseed rape) that causes the devastating stem canker in canola fields of western Canada. The population genetic structure of L. maculans, represented by nine subpopulations from a 6‐year period and three different provinces in western Canada, was determined using ten minisatellite markers. Isolates collected at different locations in six consecutive years had an even distribution of MAT1‐1 and MAT1‐2 across the nine subpopulations. All subpopulations of L. maculans exhibited a moderate gene diversity (H = 0.356–0.585). The majority of the genetic variation occurred within subpopulations. Approximately 8% and 4% of the variations were distributed between sampling year and location, respectively. Genetic distance (FST) results, using analysis of molecular variation (AMOVA), indicated that subpopulation pairing within isolates by year ranged from FST = 0.010 to 0.109, and the location subpopulation ranged from FST = 0.038 to 0.085. Bayesian clustering analyses of multiloci inferred two distinct clusters in all the subpopulations examined. This study indicates a relatively high degree of gene exchange between the different L. maculans isolates. Our results suggest that this can occur in the wide growing areas of canola fields in western Canada. This gene exchange produced different gene allele frequencies and divergence between populations. [ABSTRACT FROM AUTHOR]

Key message: CsHSP17.7, CsHSP18.1, and CsHSP21.8 expressions are induced by heat and cold stresses, and CsHSP overexpression confers tolerance to heat and cold stresses in transgenic Pichia pastoris and Arabidopsis thaliana. Abstract: Small heat shock proteins (sHSPs) are crucial for protecting plants against biotic and abiotic stresses, especially heat stress. However, knowledge concerning the functions of Camellia sinensis sHSP in heat and cold stresses remains poorly understood. In this study, three C. sinensis sHSP genes (i.e., CsHSP17.7, CsHSP18.1, and CsHSP21.8) were isolated and characterized using suppression subtractive hybridization (SSH) technology. The CsHSPs expression levels in C. sinensis leaves were significantly up-regulated by heat and cold stresses. Phylogenetic analyses revealed that CsHSP17.7, CsHSP18.1, and CsHSP21.8 belong to sHSP Classes I, II, and IV, respectively. Heterologous expression of the three CsHSP genes in Pichia pastoris cells enhanced heat and cold stress tolerance. When exposed to heat and cold treatments, transgenic Arabidopsis thaliana plants overexpressing CsHSP17.7, CsHSP18.1, and CsHSP21.8 had lower malondialdehyde contents, ion leakage, higher proline contents, and transcript levels of stress-related genes (e.g., AtPOD, AtAPX1, AtP5CS2, and AtProT1) compared with the control line. In addition, improved seed germination vigor was also observed in the CsHSP-overexpressing seeds under heat stress. Taken together, our results suggest that the three identified CsHSP genes play key roles in heat and cold tolerance. [ABSTRACT FROM AUTHOR]

GLABRA1 ( GL1) belongs to the group of R2R3-MYB transcription factors and is known to be essential for trichome initiation in Arabidopsis. In our previous study, we identified a GL1 ortholog in Brassica rapa as a candidate for the gene controlling leaf hairiness by QTL analysis and suggested that a 5-bp deletion (B-allele) and a 2-bp deletion (D-allele) in the exon 3 of BrGL1 and a non-synonymous SNP (C-allele) in the second nucleotide of exon 3 possibly cause leaf hairlessness. In this study, we transformed a B. rapa line having the B-allele with the A-allele (wild type) or the C-allele of BrGL1 under the control of the CaMV 35S promoter. The transgenic plants with the A-allele showed dense coverage of seedling tissues including stems, young leaves and hypocotyls with trichomes, whereas the phenotypes of those with the C-allele were unchanged. In order to obtain more information about allelic variation of GL1 in different plant lineages and its correlation with leaf hairiness, two GL1 homologs, i.e., RsGL1a and RsGL1b, in Raphanus sativus were analyzed. Allelic variation of RsGL1a between a hairless line and a hairy line was completely associated with hairiness in their BCF population. Comparison of the full-length of RsGL1a in the hairless and hairy lines showed great variation of nucleotides in the 3′ end, which might be essential for its function and expression. [ABSTRACT FROM AUTHOR]

SNP markers for QTL analysis of 4-MTB-GSL contents in radish roots were developed by determining nucleotide sequences of bulked PCR products using a next-generation sequencer. DNA fragments were amplified from two radish lines by multiplex PCR with six primer pairs, and those amplified by 2,880 primer pairs were mixed and sequenced. By assembling sequence data, 1,953 SNPs in 750 DNA fragments, 437 of which have been previously mapped in a linkage map, were identified. A linkage map of nine linkage groups was constructed with 188 markers, and five QTLs were detected in two F2 populations, three of them accounting for more than 50% of the total phenotypic variance being repeatedly detected. In the identified QTL regions, nine SNP markers were newly produced. By synteny analysis of the QTLs regions with Arabidopsis thaliana and Brassica rapa genome sequences, three candidate genes were selected, i.e., RsMAM3 for production of aliphatic glucosinolates linked to GSL-QTL-4, RsIPMDH1 for leucine biosynthesis showing strong co-expression with glucosinolate biosynthesis genes linked to GSL-QTL-2, and RsBCAT4 for branched-chain amino acid aminotransferase linked to GSL-QTL-1. Nucleotide sequences and expression of these genes suggested their possible function in 4MTB-GSL biosynthesis in radish roots. [ABSTRACT FROM AUTHOR]

Blackleg, caused by the fungus Leptosphaeria maculans, is an important disease of canola. Both ascospores and pycnidiospores of the fungus can infect intact leaves under conditions of extended leaf wetness, with infection then progressing further into the stem. In western Canada, spring is typically cool and dry and additional factors may be involved for successful infection. This study was designed to assess the effect of wounding and wound age on cotyledon infection, to evaluate the likelihood that flea beetle-feeding injuries could contribute to increased disease. Infection of canola cotyledons occurred readily via mechanical wounds in the absence of leaf wetness when seedlings were spray inoculated with pycnidiospores of L. maculans, whereas no infection occurred on intact cotyledons even under 6-h leaf wetness. Wound age also played a role in susceptibility; wounded tissues were less susceptible when plants were kept in a greenhouse for 8 h or longer before inoculation, with substantially reduced infection success relative to fresh wounds. This wound-age effect was similar on susceptible and resistant canola varieties. A high temperature (25°C) seemed to favour the healing of wounds, reducing susceptibility when compared with control (21/16°C) and low (10°C) temperatures. Leaf wetness post-wounding may hinder healing, and high post-inoculation humidity (80–90% relative humidity) increased infection via older wounds slightly, relative to lower (50–60%) relative humidity. These data provide a rationale for studying the effect of improved flea beetle control on early L. maculans infection of canola. [ABSTRACT FROM AUTHOR]

Verticillium stripe in canola (Brassica napus L.) caused by Verticillium longisporum was first reported in Manitoba in 2014. In this study, Brassica crops including canola, mustard (Brassica juncea) and radish (Raphanus sativus) with visible symptoms of Verticillium stripe were collected from Portage La Prairie, Manitoba, and the pathogens were isolated. Isolates from canola and radish were identified to V. longisporum, which produced longer conidia (7.92–12.00 µm) than Verticillium dahliae (4.32–7.04 µm). An isolate derived from mustard was characterized as V. dahliae. Molecular diagnostics with 18S rDNA, 5.8S rDNA and mating-type marker primers were used to confirm the identification of Verticillium isolates. PCR-RFLP of the mitochondrial small subunit rDNA and the cytochrome b gene were also employed to distinguish V. longisporum isolates from V. dahliae. The multi-gene characterization approach allowed for lineage determination, and V. longisporum isolates from canola and radish were in the A1/D1 group. Isolates of Verticillium longisporum from canola inoculated onto the canola cultivar 'Westar' caused symptoms of stem striping, stunting and short plants. Re-isolated fungal strains from infected stems were again inoculated onto canola plants, in order to confirm that V. longisporum was the causal agent of Verticillium stripe disease in the pathogenicity test. [ABSTRACT FROM AUTHOR]

JAZ (Jasmonate ZIM-domain) proteins play pervasive roles in plant development and defense reaction. However, limited information is known about the JAZ family in Camellia sinensis. In this study, 12 non-redundant JAZ genes were identified from the tea plant genome database. Phylogenetic analysis showed that the 12 JAZ proteins belong to three groups. The cis-elements in promoters of CsJAZ genes and CsJAZ proteins interaction networks were also analyzed. Quantitative RT–PCR analysis showed that 7 CsJAZ genes were preferentially expressed in roots. Furthermore, the CsJAZ expressions were differentially induced by cold, heat, polyethylene glycol (PEG), methyl jasmonate (MeJA), and gibberellin (GA) stimuli. The Pearson correlations analysis based on expression levels showed that the CsJAZ gene pairs were differentially expressed under different stresses, indicating that CsJAZs might exhibit synergistic effects in response to various stresses. Subcellular localization assay demonstrated that CsJAZ3, CsJAZ10, and CsJAZ11 fused proteins were localized in the cell nucleus. Additionally, the overexpression of CsJAZ3, CsJAZ10, and CsJAZ11 in E. coli enhanced the growth of recombinant cells under abiotic stresses. In summary, this study will facilitate the understanding of the CsJAZ family in Camellia sinensis and provide new insights into the molecular mechanism of tea plant response to abiotic stresses and hormonal stimuli. [ABSTRACT FROM AUTHOR]

Blackleg (Phoma stem canker) of crucifers is a globally important disease caused by the ascomycete species complex comprising of Leptosphaeria maculans and Leptosphaeria biglobosa. Six blackleg isolates recovered from Brassica rapa cv. Mizspoona in the Willamette Valley of Oregon were characterized as L. biglobosa based on standard pathogenicity tests and molecular phylogenetic analysis. These isolates were compared to 88 characterized L. biglobosa isolates from western Canada, 22 isolates from Australia, and 6 L. maculans isolates from Idaho, USA using maximum parsimony and distance analysis of phylogenetic trees generated from the ITS rDNA (internal transcribed spacer rDNA) sequence, and the actin and β-tubulin gene sequences. The L. biglobosa isolates derived from B. rapa collected in Oregon formed a separate subclade based on concatenated gene sequences or a single gene sequence, regardless of the analyses. Pathogenicity tests showed that these isolates failed to infect either resistant or susceptible B. napus cultivars, but caused severe symptoms on three B. rapa cultivars (Accession number: UM1113, UM1112, and UM1161), a B. oleracea var. capitata (cabbage) cultivar (Copenhagen Market), and two B. juncea cultivars (CBM, a common brown Mustard, and Forge). These findings demonstrated that the L. biglobosa isolates derived from a B. rapa crop in Oregon were genetically distinct from existing species of L. biglobosa, and constitute a new subclade, herein proposed as L. biglobosa 'americensis'. [ABSTRACT FROM AUTHOR]

Callose plays a critical role in different biological processes including development as well as in the response to multiple biotic and abiotic stresses. In this study, we characterized the callose deposition in cotyledons of different Brassica napus varieties post-inoculated with different Leptosphaeria maculans isolates. Further, members of the callose synthase gene were identified from the whole genome of B. napus using the 12 Arabidopsis thaniana callose synthase protein sequences, and were then classified into three groups based on their phylogenetic relationships. Chromosomal location and duplication patterns indicated uneven distribution and segmental duplication patterns of BnCalS genes in the B. napus genome. Subsequently, gene structures, conserved domains analysis, and protein properties were analyzed for BnCalS genes. In addition, 12 B. napus orthologs of the AtCalS were selected for investigating the tissue expression pattern, indicating diverse expression patterns for these BnCalS genes. Responses of the selected 12 orthologs and all the BnCalS genes were characterized in the different types (AvrLm1-Rlm1, AvrLm4-Rlm4, AvrLepR1-LepR1) of B. napus–L. maculans interactions and B. napus-Leptosphaeria biglobosa interactions, implying their potential roles in response to Leptosphaeria infection. [ABSTRACT FROM AUTHOR]

Genetic diversity is vital for the survival of any population. If humans were all the same, a single strain of a nasty flu virus, like COVID-19, could wipe us all out! In plants, genetic diversity plays a similar role. The variation in the type and number of resistance gene(s) between individuals can cause the difference between surviving a disease or not. Studies on genetic diversity will lead to the identification of novel disease-resistance genes. Canola (Brassica napus L.) is an economically and nutritionally important oilseed worldwide. Several serious diseases, including blackleg, clubroot, sclerotinia stem rot, and verticillium stripe, threaten canola production in Canada and worldwide. Traditional methods are not enough for effective control of these diseases. Therefore, the ideal approach is to optimize and utilize the resistance genes found in different B. napus cultivars. With the advent of next-generation sequencing and the development of genomics and molecular genetics techniques, it is now possible to rapidly identify and apply resistance genes. This paper reviews current information about disease-resistance genes identified in B. napus cultivars, mapping and cloning, their importance, role and function, and their association with plant disease resistance and application in resistance breeding. The feasibility of using current resistance sources in Canadian cultivars for developing new disease-resistant cultivars is also discussed. Sustainability of a farm and an agricultural system could be maintained by breeding for disease resistance, including the resistant varieties and incorporating other integrated pest management strategies along with it. [ABSTRACT FROM AUTHOR]

Background: Intercropping, especially with legumes, as a productive and sustainable system, can promote plants growth and improves the soil quality than the sole crop, is an essential cultivation pattern in modern agricultural systems. However, the metabolic changes of secondary metabolites and the growth in tea plants during the processing of intercropping with soybean have not been fully analyzed. Results: The secondary metabolomic of the tea plants were significant influence with intercropping soybean during the different growth stages. Especially in the profuse flowering stage of intercropping soybean, the biosynthesis of amino acids was significantly impacted, and the flavonoid biosynthesis, the flavone and flavonol biosynthesis also were changed. And the expression of metabolites associated with amino acids metabolism, particularly glutamate, glutamine, lysine and arginine were up-regulated, while the expression of the sucrose and D-Glucose-6P were down-regulated. Furthermore, the chlorophyll photosynthetic parameters and the photosynthetic activity of tea plants were higher in the tea plants-soybean intercropping system. Conclusions: These results strengthen our understanding of the metabolic mechanisms in tea plant's secondary metabolites under the tea plants-soybean intercropping system and demonstrate that the intercropping system of leguminous crops is greatly potential to improve tea quality. These may provide the basis for reducing the application of nitrogen fertilizer and improve the ecosystem in tea plantations. [ABSTRACT FROM AUTHOR]

Background: Intercropping, especially with legumes, as a productive and sustainable system, can promote plants growth and improves the soil quality than the sole crop, is an essential cultivation pattern in modern agricultural systems. However, the metabolic changes of secondary metabolites and the growth in tea plants during the processing of intercropping with soybean have not been fully analyzed. Results: The secondary metabolomic of the tea plants were significant influence with intercropping soybean during the different growth stages. Especially in the profuse flowering stage of intercropping soybean, the biosynthesis of amino acids was significantly impacted, and the flavonoid biosynthesis, the flavone and flavonol biosynthesis also were changed. And the expression of metabolites associated with amino acids metabolism, particularly glutamate, glutamine, lysine and arginine were up-regulated, while the expression of the sucrose and D-Glucose-6P were down-regulated. Furthermore, the chlorophyll photosynthetic parameters and the photosynthetic activity of tea plants were higher in the tea plants-soybean intercropping system. Conclusions: These results strengthen our understanding of the metabolic mechanisms in tea plant's secondary metabolites under the tea plants-soybean intercropping system and demonstrate that the intercropping system of leguminous crops is greatly potential to improve tea quality. These may provide the basis for reducing the application of nitrogen fertilizer and improve the ecosystem in tea plantations. [ABSTRACT FROM AUTHOR]

γ-Aminobutyric acid (GABA), a signal molecule, is regarded as the intersection node of carbon and nitrogen metabolism, and its contributions to flavonoid metabolism in tea plant growth and development remain unclear. The correlation between the GABA shunt and flavonoid metabolism in tea plants is worth to explore. Secondary metabolites and their correlations with the taste of tea soup made from tea plants (Camellia sinensis) during different seasons were investigated. Related secondary metabolites and transcript profiles of genes encoding enzymes in the GABA shunt, flavonoid pathway and polyamine biosynthesis were measured throughout the tea plant growth seasons and after exogenous GABA applications. In addition, the abundance of differentially expressed proteins was quantified after treatments with or without exogenous GABA. The tea leaves showed the highest metabolite concentrations in spring season. CsGAD , CsGABAT , CsSPMS , CsODC , CsF3H and CsCHS were found to be important genes in the GABA and anthocyanin biosynthesis pathways. GABA and anthocyanin concentrations showed a positive correlation, to some extent, CsF3H and CsCHS played important roles in the GABA and anthocyanin biosynthesis. ● The correlation between the GABA shunt and flavonoid metabolism in tea plants was firstly explored. ● Secondary metabolites and related genes in the GABA shunt and flavonoid biosynthesis were monitored throughout the whole growth season. ● CsF3H and CsCHS played important roles in the GABA and anthocyanin network. ● The regulation of Anthocyanin and flavonoid biosynthetic pathway was influenced by signaling molecule (GABA). [ABSTRACT FROM AUTHOR]

Amino acid permeases (AAPs) are involved in transporting a broad spectrum of amino acids and regulating physiological processes in plants. In this study, 19 AAP genes were identified from the tea plants genome database and named CsAAP1–19. Based on phylogenetic analysis, the CsAAP genes were classified into three groups, having significantly different structures and conserved motifs. In addition, an expression analysis revealed that most of CsAAP genes were specifically expressed in different tissues, especially CsAAP19 was expressed only in root. These genes also were significantly expressed in the Baiye 1 and Huangjinya cultivars. Nitrogen treatments indicated that the CsAAP s were obviously expressed in root. CsAAP2 , − 6 , − 12 , − 13 and − 16 were significantly expressed at 6 d after the glutamate treatment, while the expression trend at 24 h after contained the ammonium. These results improve our understanding of the CsAAP genes and their functions in nitrogen utilization in tea plants. [ABSTRACT FROM AUTHOR]

• LmCBP1 is a secreted protein and can bind to chitin. • Knockout of LmCBP1 in Leptosphaeria maculans using CRISPR-Cas9 lowered the pathogenicity of this pathogen on Brassica napus. • The knockout mutants of LmCBP1 were more sensitive to hydrogen peroxide. Leptosphaeria maculan s is the causal agent of blackleg disease on Brassica napus. Determining the underlying functions of genes required for pathogenesis is essential for understanding the infection process. A chitin-binding protein (LmCBP1) was discovered as a pathogenicity factor for the infection of B. napus by L. maculans through gene knockout using the CRISPR-Cas9 system. Chitin-binding activity was demonstrated through a chitin-protein binding assay. A secreted signal peptide was detected using a yeast secreted-signal peptide trap assay. An increased expression level during the infection stage was also observed, suggesting that LmCBP1 is a secreted protein. The knockout mutants showed decreased infection on B. napus , with reduced pathogenicity on ten cultivars with/without diverse R genes. The mutants were more sensitive to H 2 O 2 compared to wild type L. maculans isolate JN3. This study provides evidence of the virulence of a novel chitin-binding protein LmCBP1 on B. napus through mutants created via the CRISPR-Cas9 system. [ABSTRACT FROM AUTHOR]

Nymphaea-like BiOCl with oxygen vacancies (OVs) was successfully prepared by adjusting the pH of the precursor and using aspartic acid as a surfactant. The as-fabricated samples were investigated by the XRD, SEM, TEM, BET, DRS, PL and SPV techniques. The results reveal that the morphology of the as-prepared samples was self-assembled by thinner nanosheets. Moreover, the sample prepared at pH = 4 can remove 80% of tetracycline hydrochloride (TC, 10 mg L−1) in 1 h. This outstanding photocatalytic performance is attributed to the shorter migration distance of photo-induced carriers due to the thinner nanosheets and the high separation efficiency of photo-generated electron–hole pairs induced by OVs. Furthermore, the dominant free radicals in the present system were identified by trapping experiments and ESR methods. This work provides a new ideal to augment the photocatalytic activity of BiOCl through morphology control and defect engineering. [ABSTRACT FROM AUTHOR]

Background: Tea plant (Camellia sinensis) is one of the most popular non-alcoholic beverages worldwide. In tea, lateral roots (LRs) are the main organ responsible for the absorption of moisture and mineral nutrients from the soil. Lateral roots formation and development are regulated by the nitrogen and auxin signaling pathways. In order to understand the role of auxin and nitrogen signaling in LRs formation and development, transcriptome analysis was employed to investigate the differentially expressed genes involved in lateral roots of tea plants treated with indole-3-butyric acid (IBA), N-1-naphthylphthalamic acid (NPA), low and high concentrations of nitrogen. Results: A total of 296 common differentially expressed genes were identified and annotated to four signaling pathways, including nitrogen metabolism, plant hormone signal transduction, glutathione metabolism and transcription factors. RNA-sequencing results revealed that majority of differentially expressed genes play important roles in nitrogen metabolism and hormonal signal transduction. Low nitrogen condition induced the biosynthesis of auxin and accumulation of transcripts, thereby, regulating lateral roots formation. Furthermore, metabolism of cytokinin and ethylene biosynthesis were also involved in lateral roots development. Transcription factors like MYB genes also contributed to lateral roots formation of tea plants through secondary cell wall biosynthesis. Reversed phase ultra performance liquid chromatography (RP-UPLC) results showed that the auxin concentration increased with the decreased nitrogen level in lateral roots. Thus, tea plant lateral roots formation could be induced by low nitrogen concentration via auxin biosynthesis and accumulation. Conclusion: This study provided insights into the mechanisms associated with nitrogen and auxin signaling pathways in LRs formation and provides information on the efficient utilization of nitrogen in tea plant at the genetic level. [ABSTRACT FROM AUTHOR]

BiOCl/g‐C3N4 (BOC/CN) n‐p heterojunction with rich oxygen vacancies (OVs) was successfully prepared by microwave‐assistant strategy. Multiple characterizations revealed that BOC/CN‐10 exhibited excellent photodegradation performance and degraded 49 % carbamazepine (50 mL, 2.5 mg/L) in 240 minutes, which was eight and three times higher than BiOCl and g‐C3N4, respectively. ESR and O2‐TPD were combined to determine the presence of OVs in BOC/CN. Moreover, the photocatalytic mechanism demonstrates that the OVs of BiOCl and novel p‐n heterostructure not only extend the light absorption but also facilitate the spatial separation of photoinduced carries, and thus BOC/CN‐10 possesses outstanding photocatalytic performance. This work inspired how to improve photocatalytic activity by defect engineering and p‐n heterostructure strategy for Bismuth‐based photocatalyst. [ABSTRACT FROM AUTHOR]

Novel BiOCl/BiOBr heterojunction with rich oxygen vacancies (OVs) was successfully synthesized via ultrasound and photoinduced method. The XRD, SEM, TEM, XPS, DRS, ESR, SPV, PL, contact angle and electrochemical technique were implemented to characterize the as‐synthesized samples. The experiment results demonstrated that BOCBuv can degrade carbamazepine (2.5 mg/L) by nearly 60 % during 180 min under visible light irradiation, which is 2, 3, 7 times higher than that of BOCB, BOC and BOB, respectively. Furthermore, the presence of OVs and heterojunction structure not only enhance the light absorption but also improve the spatial separation and migration of photogenerated carriers, and thus BOCBuv exhibits polish photocatalytic performance. This research provides a new approach and insight for developing novel efficiency photocatalysts by tailoring surface defects and heterojunction structure. [ABSTRACT FROM AUTHOR]

Photocatalysis is an effective technique for degrading contaminants, however, its effect is inhibited by the high recombination rate of photo‐induced carriers in the photocatalyst. Therefore, this drawback can be overcome by defect engineering (such as oxygen vacancies) and heterostructure, which can expand light response as well as promote the separation and migration of photo‐induced carriers. Herein, BiOCl/ZnO nanocomposite was successfully synthesized by microwave strategy. Experimental results indicated that tetracycline hydrochloride (TC‐HCl, 100 mg/L) was decomposed 90% in 60 min by BiOCl/ZnO heterostructure under visible light, which is 3.34 and 1.08 times higher than that of pristine BiOCl and ZnO, respectively. Various characterizations demonstrated that oxygen vacancy and heterostructures not only extend the light response range but also improve the separation and migration efficiency of photo‐induced carriers, and thereby BiOCl/ZnO heterostructure exhibit excellent photocatalytic performance under vis‐light. This work paves a new way to decorate wide band gap photocatalyst by point defect and heterostructures, and provides a good reference for its application. [ABSTRACT FROM AUTHOR]

A feathery-shaped form of BiOCl (BOC-M) with a high concentration of oxygen vacancies was successfully synthesized using the ultrasound method at room temperature with maltitol as a surfactant. BOC-M was found to exhibit excellent visible-light photocatalytic activities for the degradations of the antibiotic tetracycline hydrochloride (TC-HCl) and rhodamine B (RhB), whose reaction rate was found to be approximately 3 times higher than that using bulk BiOCl (BOC). The enhanced visible photocatalytic performance of BOC-M was ascribed to its high concentration of oxygen vacancies, large specific surface area and strong hydrophilicity. Moreover, the photocatalytic reaction mechanism was further revealed by performing radical- and hole-trapping experiments and electron spin resonance spectroscopy (ESR). The results suggested that ṖO2− was the main active species during the degradation process. This work provided a facile and scalable method to synthesize maltitol-assisted Bi-based photocatalysts and shed light on the highly efficient catalysis offered by BiOCl resulting from the oxygen vacancies produced by the new synthetic route we developed. [ABSTRACT FROM AUTHOR]

Graphical abstract The BiOCl nanosheets prepared with 0.1 g concentration of mannitol (BOC-1) exhibited the best photocatalytic activity under visible light attributed to its highly crystalline, porous structure and positive valence band. Highlights • The porous BiOCl nanocubes were synthesized using mannitol. • Mannitol can impact on crystal structure and morphology as well as photocatalytic activity. • A photocatalytic mechanism is for its highly crystalline, porous structure, positive valence band and dye sensitized. Abstract Porous BiOCl nanocubes with highly crystalline was successfully synthesized via a facile mannitol-assisted hydrothermal route. The results reveal that mannitol has great influence on BiOCl crystal structure and morphology, as well as photocatalytic activity. BiOCl (k = 0.190 min−1) exhibits excellent photocatalytic activities by the degradation of Rhodamine B (RhB) almost completely after 20 min visible-light irradiation. The enhanced photocatalytic-activity is owing to its highly crystalline, porous structure and positive valence band. This work provides a green strategy on synthesizing porous Bi-based nanocubes with highly active photocatalysis and offers new inside the importance of mannitol on the photocatalysis preparation process. [ABSTRACT FROM AUTHOR]

The square-sharped BiOCl nanosheets with oxygen vacancies were successfully synthesized via a facile hydrothermal route using xylitol as surfactant. The as-prepared BiOCl samples were characterized by Powder X-ray Diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), UV–Vis diffuse reflectance spectra (DRS), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and Electron spin resonance (ESR). The as-prepared samples were phase-pure with the width and the thickness were about 50–400 nm and 20–50 nm respectively. Besides, the photodegradation performances showed the BiOCl nanosheets with 0.1 g concentration of xylitol (BOC-1) had the best photocatalytic activity under visible light due to its special polycrystalline structure, grain boundary and an optimum concentration of oxygen vacancies. The h + and O 2 − were the two main active species during the photocatalytic process and the possible photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Background: Self-incompatibility (SI) is a major barrier that obstructs the breeding process in most horticultural plants including tea plants (Camellia sinensis). The aim of this study was to elucidate the molecular mechanism of SI in tea plants through a high throughput transcriptome analysis. Results: In this study, the transcriptomes of self- and cross-pollinated pistils of two tea cultivars 'Fudingdabai' and 'Yulv' were compared to elucidate the SI mechanism of tea plants. In addition, the ion components and pollen tube growth in self- and cross-pollinated pistils were investigated. Our results revealed that both cultivars had similar pollen activities and cross-pollination could promote the pollen tube growth. In tea pistils, the highest ion content was potassium (K+), followed by calcium (Ca2+), magnesium (Mg2+) and phosphorus (P5+). Ca2+ content increased after self-pollination but decreased after cross-pollination, while K+ showed reverse trend with Ca2+. A total of 990 and 3 common differentially expressed genes (DEGs) were identified in un-pollinated vs. pollinated pistils and self- vs. cross-pollinated groups after 48 h, respectively. Function annotation indicated that three genes encoding UDP-glycosyltransferase 74B1 (UGT74B1), Mitochondrial calcium uniporter protein 2 (MCU2) and G-type lectin S-receptor-like serine/threonine-protein kinase (G-type RLK) might play important roles during SI process in tea plants. Conclusion: Ca2+ and K+ are important signal for SI in tea plants, and three genes including UGT74B1, MCU2 and G-type RLK play essential roles during SI signal transduction. [ABSTRACT FROM AUTHOR]

BiO 1− x Cl with optimum surface oxygen vacancies modulate the surface spatial electron structure and local electric field, and thus substantial photo-generated electrons were effectively ferry to the confined PMS by electron shuttles and hamper its random adsorption and disorder self-quenching. Ultimately, outstanding PMS utilization rate and pollutant removal rate was obtained. [Display omitted] • BiO 1− x Cl with optimum surface oxygen vacancies was prepared. • Surface oxygen vacancies confine activation PMS. • Surface oxygen vacancies halted the self-quenching of active species population. • Surface oxygen vacancies significantly boosted PMS utilization rate. Hinder self-quenching of active species and augment peroxymonosulfate (PMS) utilization rate is a challenging for advanced oxidation processes (AOPs). Therefore, BiO 1−x Cl with appropriate surface oxygen vacancies (SOVs) was fabricated by microwave reduction method. Experimental results reflect that BOC-2 can remediate 79.4 % doxycycline hydrochloride (50 mg L−1) in 1.75 h under the constantly yield active species population (ASP). Simultaneously, theoretical calculation discerns that reasonable SOVs can increase PMS adsorption energy, change PMS adsorption configuration and peroxy bond length. Thus, photo-induced electrons can fast ferry to the confined PMS via electron shuttles formed by SOVs to activate PMS. Ultimately, ASP self-quenching was halted and PMS utilization rate was ameliorated. Furthermore, the structure–activity relationship between SOVs and PMS utilization rate was established and the environmental toxicity of the intermediates was evaluated. This work offers an ingenious strategy to steer PMS activating behavior and boost its utilization rate by defect engineering. [ABSTRACT FROM AUTHOR]

Oil palm (Elaeis guinensis Jacquin) is the most important source of vegetable oil and fat. Several linkage maps had been constructed using dominant and co-dominant markers to facilitate mapping of QTL. However, dominant markers are not easily transferable among different laboratories. We constructed a consensus linkage map for oil palm using co-dominant markers (i.e. microsatellite and SNPs) and two F1 breeding populations generated by crossing Dura and Pisifera individuals. Four hundreds and forty-four microsatellites and 36 SNPs were mapped onto 16 linkage groups. The map length was 1565.6 cM, with an average marker space of 3.72 cM. A genome-wide scan of QTL identified a major QTL for stem height on the linkage group 5, which explained 51% of the phenotypic variation. Genes in the QTL were predicted using the palm genome sequence and bioinformatic tools. The linkage map supplies a base for mapping QTL for accelerating the genetic improvement, and will be also useful in the improvement of the assembly of the genome sequences. Markers linked to the QTL may be used in selecting dwarf trees. Genes within the QTL will be characterized to understand the mechanisms underlying dwarfing. [ABSTRACT FROM AUTHOR]

• Small RNA sequencing identified 424 conserved and 417 novel miRNAs of Camellia sinensis. • Degradome sequencing identified 599 targets predicted to be cleaved by 210 conserved and 70 novel miRNAs. • The susceptibility of LJ43 against C. gloeosporioides stress is mainly due to the repression of auxin signal. • Caffeine-induced miRNA-mediated target genes were actively involved in the regulation of JA mediated pathway. • Caffeine-induced miRNAs target genes were altered the LJ43 nature to resistance environment against C. gloeosporioides. Anthracnose, caused by Colletotrichum gloeosporioides is one of the most serious diseases of tea plant [ Camellia sinensis (L.) O. Kuntze]. MicroRNAs are key modulators of gene expression in defense responses and plant immunity; although, foliar application of exogenous caffeine in anthracnose disease control management has proven to be effective, miRNA-mediated regulatory mechanisms underlying caffeine-induced plant defense response to C. gloeosporioides remain unexplored in tea plant. Using high-throughput-sequencing, 24 miRNA sequencing data sets and 8 degradome data sets were generated from the susceptible cultivar Longjing43 (LJ43) and the resistant cultivar Zhongcha108 (ZC108) leaves treated with CK (Water), C. gloeosporioides -inoculation (CgI), exogenous caffeine (CN) and CgI + CN. Using sRNA sequencing, 424 conserved miRNAs and 417 novel miRNAs were identified; of these, 146 and 130 miRNAs were differentially expressed under CgI + CN treatment in the LJ43 and ZC108, respectively. Degradome sequencing identified 599 targets predicted to be cleaved by 210 conserved and 70 novel miRNAs. Majority of the annotated targets were found to involve in regulation of transcription factors, oxidation-reduction and metabolic process for plant growth and development as well as stress responses in tea plant against C. gloeosporioides stress. The expression pattern of eight miRNAs and their targets were validated by qRT-PCR, and correlation analysis of csn-miR164a_R+1_1ss21AG/NAC-17 and csn-miR396b-5p/GRF-1 showed highly significant negative R-value at 7th dpi under CgI + CN in the LJ43. This study provides important insights into the novel approach of exogenous caffeine-induced miRNAs dynamically exerts its fungicidal activity through regulating JA/ET signaling pathway, thereby accurately switch on LJ43 susceptibility nature to resistance activity against C. gloeosporioides infection. [ABSTRACT FROM AUTHOR]

The optimized interface OVs concentration not only reduced the migration resistance of the photo-induced carriers at the interface under the driven of built-in electric field, but also effectively inhibit the recombination of photo-generated carriers, resulting in excellent photocatalytic performance. • Supply a novel ideal to estimate the interface OVs concentration. • The migration resistance of carriers was greatly decreased by the interface OVs. • 0D/2D Bi 2 O 2 CO 3 /BiOCl present wonderful photocatalytic activity. Enhancing the separation and migration efficiency of the photo-induced carriers is an appealing strategy to augment the photocatalytic performance. Herein, 0D/2D Bi 2 O 2 CO 3 /BiOCl heterojunction with rich interface oxygen vacancy (OVs) was successfully fabricated by in-situ ion exchange avenue using sodium citrate as CO 3 2− source. Multiple characterizations reveal that BOBl can degrade 84% tetracycline hydrochloride (TC) in 60 min, which is 6.4 and 6.0 fold higher than that of BiOCl and Bi 2 O 2 CO 3 , respectively. Moreover, further research found that the impressive activity of 0D/2D Bi 2 O 2 CO 3 /BiOCl emanates from the large surface area and the polishing separation and migration efficiency of the photo-generated carriers induced by the reasonable interface OVs concentration. Additionally, the OVs concentration of Bi 2 O 2 CO 3 , BiOCl and interface in 0D/2D Bi 2 O 2 CO 3 /BiOCl composites were estimated based on Raman and ESR techniques. This work not only provides a novel avenue to identify the components OVs concentration in heterostructure, but also offers a new ideal to ameliorate photocatalytic performance through interfacial defect engineering. [ABSTRACT FROM AUTHOR]

To understand the effects of geographic locations, cultivation altitude, slope, and aspect on secondary metabolites in tea leaves, 78 tea samples were randomly collected from Southern Jiangsu region, China, and catechins, caffeine, and free amino acids were examined. The results showed that samples from the farther north had higher contents of TC, EGCG + GCG, ECG + CG and the ratios of ETC to NTC, while had lower contents of free amino acids, leading to more bitterness and astringency taste in tea. Furthermore, more free amino acids were accumulated in tea cultivated in hilly areas due to shorter sun exposure time and lower intensity than plain areas with the rotation of the earth formed a natural shade management effect, whereas more TC in plain areas. Principal Component Analysis (PCA) grouped the 78 tea samples into three clusters and further confirmed that tea samples from a similar geographical environment exhibited a similar constituent of major secondary metabolites. These results might be useful for providing references to regional tea plantation planning, tea plantations location selection and geographical environment management. • Catechins and free amino acids contents in tea are affected by cultivation location. • Tea cultivated in hilly areas gets more free amino acid due to topographic shading. • Tea cultivated in plain areas gets more TC due to longer sun exposure time. • Tea cultivated in similar geographical environment gets similar secondary metabolites. [ABSTRACT FROM AUTHOR]

• La(OH) 3 /BiOCl n-n heterojunctions with high oxygen vacancy were synthesized. • La(OH) 3 /BiOCl shows excellent photocatalytic activity for multiple contaminants. • The activity was improved by oxygen vacancy and internal electric field. La(OH) 3 /BiOCl n-n heterojunction (BCL) was successfully fabricated by facile microwave technique. Photocatalytic performance experiments confirmed that BCL-20 can degrade 20 mg/L tetracycline hydrochloride (TC-HCl) about 85% in 60 min, which is 2 and 0.5 times higher than that of BiOCl and La(OH) 3 , respectively. The photocatalytic mechanism reveals that the co-effect of oxygen vacancies (OVs) and rebuilt internal electric field induced by heterostructure not only broaden the light-responsive range but also augment the separation efficiency of photogenerated carriers, thus improving the photocatalytic properties of BCL. This work provides a new avenue for improving the photocatalytic performance of Bi-based photocatalysts by heterojunction and OVs. [ABSTRACT FROM AUTHOR]