Biotrophic pathogens depend on host carbon sources for proliferation. Here, we identified BnaA07.SUC2 in oilseed rape (Brassica napus cv. Westar), which encodes a plasma membrane-localized proton-dependent sucrose transporter. Its expression is markedly induced in roots during the late stages of Plasmodiophora brassicae infection. The Arabidopsis thaliana suc2 mutant exhibited a strong clubroot-resistant phenotype, and functional complementation with BnaA07.SUC2 restored susceptibility to P. brassicae. Overexpression of BnaA07.SUC2 in oilseed rape significantly increased sucrose accumulation and disease susceptibility, whereas CRISPR/Cas9-mediated knockout of BnaA07.SUC2 enhanced clubroot resistance. Furthermore, yeast one-hybrid, dual-luciferase, and electrophoretic mobility shift assays showed that BnaA05.MYC2 directly binds to the BnaA07.SUC2 promoter and represses its expression. Overexpression of BnaA05.MYC2 in oilseed rape enhanced clubroot resistance, which was accompanied by reduced BnaA07.SUC2 transcript levels. Conversely, co-overexpression of BnaA07.SUC2 in the BnaA05.MYC2-overexpressing oilseed rape background restored susceptibility, indicating that BnaA05.MYC2 promotes clubroot resistance by repressing BnaA07.SUC2. BnaA05.MYC2 expression is induced by jasmonate (JA) signaling. JA signaling is activated during early infection but suppressed in later stages, and accordingly, BnaA05.MYC2 expression is upregulated initially but downregulated later. This downregulation relieves the repression of BnaA07.SUC2, thereby enhancing sucrose supply to the pathogen. Our study identifies the SUC transporter BnaA07.SUC2 and its regulator BnaA05.MYC2 as key susceptibility components in P. brassicae pathogenesis, providing important insights into the interaction between P. brassicae and its host plant.

Plasmodiophora brassicae poses a severe threat to rapeseed (Brassica napus) production worldwide. As an obligate biotrophic pathogen, it deploys effectors to suppress host immunity, yet how these effectors manipulate plant defence, particularly salicylic acid (SA)-b-mediated immunity, remains largely unknown. In this study, a CBM1 (carbohydrate-binding module)-containing effector, PbCBM1, from P. brassicae was identified, which is secreted and suppresses INF1/BAX-induced cell death. PbCBM1-overexpressing Arabidopsis showed significantly elevated susceptibility to P. brassicae. AtPHB3 (Prohibitin 3), a key regulator of SA biosynthesis, was identified as the interactor of PbCBM1 both in vivo and in vitro. The phb3 mutant also exhibited increased susceptibility, suggesting that PbCBM1 may promote plant susceptibility by targeting AtPHB3 during pathogen infection. The subsequent results showed that PbCBM1-overexpressing plants reduced SA pathway gene expression and isochorismate/SA accumulation upon chitin treatment. Furthermore, LUC and competitive Co-IP assays revealed that PbCBM1 competes with AtICS1 (Isochorismate synthase 1) for AtPHB3 binding. Collectively, P. brassicae secretes the effector PbCBM1 to competitively target AtPHB3, disrupting AtPHB3-AtICS1 complex integrity, thereby suppressing SA biosynthesis and immunity. This study reveals a novel molecular mechanism by which a biotrophic pathogen subverts plant defence and provides potential targets for breeding clubroot-resistant rapeseed varieties.

Brassica napus, one of the most important oil crops cultivated globally, is severely impacted by prolonged soil contamination with cadmium (Cd), resulting in decreased yields and poor seed quality. This crop exhibits a high adsorption capacity for Cd, making creating seed resources with low Cd accumulation an essential strategy to alleviate this challenge. To address this issue, we genetically edited BnaNRAMP1 in B. napus by targeting three different exon regions, resulting in new germplasm resources with significant differences in Cd accumulation capacity and unaffected yield. Among these, the mutant K140-22, specifically targeting the 7th exon, is distinguished by its substantially reduced Cd accumulation. Further, enzyme assays of the antioxidant defense system in both roots and shoots of K140-22 revealed its enhanced antioxidant activity, which contributes to elucidating the molecular mechanisms of plant tolerance to heavy metal stress. Remarkably, this mutant also maintained equivalent agronomic traits and seed quality, which highlights its potential as a germplasm resource for rapeseed breeding for low Cd accumulation and elevating rapeseed economic value in Cd-contaminated soil.

ABRE BINDING FACTOR 4 (ABF4) is a pivotal regulatory gene in the abscisic acid (ABA) signaling pathway, and changes in its expression levels can modulate the plant's stress resistance. To further explore the specific regulatory mechanisms of alternative splicing (AS) in the ABA signaling pathway and to identify new breakthroughs for breeding high stress-resistant varieties of Brassica napus, we identified 17 homologous genes of ABF4 in the genome. Utilizing bioinformatics techniques, we analyzed their motifs, conserved domains, and cis-acting elements of their promoters. Through transcriptome data from the stress-tolerant dwarf strain ndf2 and its parental line 3529, we uncovered a significantly differentially expressed ABF4 gene, which we named BnABF4L. Subsequently, we analyzed the AS events of BnABF4L under normal growth conditions and different abiotic stresses, as well as the impact of different transcript variants' 5’ untranslated region (5'UTR) on gene translation. BnABF4L undergoes alternative 3' splice site (A3SS) selection to produce three transcripts (V1-V3) with divergent 5'UTRs. While V1 translation is suppressed by upstream ORFs (uORFs), V2/V3 exhibit enhanced translational efficiency. Under stress, ndf2 shifts splicing toward V3, circumventing uORF-mediated repression to upregulate stress-adapted isoforms. We validated the inhibitory effect of upstream open reading frames (uORFs) on protein-coding open reading frame (pORFs) and, based on the collective experimental results, proposed the flexible regulatory mechanism of AS events of BnABF4L in response to stress. Our findings provide new insights for future studies on stress resistance in rapeseed as well as for research on the regulation of alternative splicing mechanisms in the ABA signaling pathway.

Plasmodiophora brassicae is a devastating intracellular pathogen that causes clubroot disease in Brassicaceae plants, leading to significant economic losses in agriculture. Enhancing plant resistance against P. brassicae has become a crucial global challenge. In this study, we report a new secreted protein, PbEL04, which can trigger cell death associated with H2O2 accumulation and electrolyte leakage in the non-host plant Nicotiana benthamiana but enhances the resistance to P. brassicae when overexpressed in Arabidopsis thaliana. Subsequently, AtSAMS2, which interacts with PbEL04, was identified in a screen of a Y2H library and confirmed by Co-IP as well as BiFC, and the expression of AtSAMS2 was significantly increased during the cortical infection stage. Furthermore, overexpressing AtSAMS2 in Arabidopsis exhibited higher susceptibility to P. brassicae than the wild type, while the mutant showed significantly elevated resistance without affecting plant growth and development, suggesting that AtSAMS2 could be a negative factor in resistance to P. brassicae infection. Taken together, our results suggest that P. brassicae infection secretes an effector protein, PbEL04, which could interact with AtSAMS2 and affect the hormone signaling pathways to influence the formation of root swelling. Here, we discovered a new effector protein, PbEL04, and identified its host interactor, AtSAMS2, which holds great potential in plant breeding as a key genetic target for clubroot resistance.

Rapeseed (Brassica napus) is a globally significant oilseed crop with strong heterosis performance. Recessive genic male sterility (RGMS) is one of the key approaches for utilizing heterosis in B. napus. However, this method faces the inherent challenge of being time-consuming and labour-intensive for removing fertile plants during seed production. Here, we report a hypocotyl length-regulated gene, BnHL, which is closely linked to a known fertility gene, BnMs2, serving as a seedling morphology marker. This marker could be used to identify fertile plants in the breeding of RGMS lines based on hypocotyl traits. By targeting the BnHL gene, both homozygous and heterozygous edited mutants exhibited significantly longer hypocotyls than the wild type (WT). Furthermore, germination experiments revealed that 7 days after seed germination, the difference in hypocotyl length between the mutant and the WT seedlings reached its maximum, effectively distinguishing fertile plants under both white (W) and red/far-red (R/FR) light. Mutations in BnHL did not result in significant changes in main agronomic traits. Thus, this study provides a comprehensive strategy for screening and identifying a new morphological marker gene for early screening in RGMS hybrid breeding with completely non-transgene during the whole production.

A collective synthesis of the C7 epoxyquinones has been achieved by a concise and flexible strategy, in which the employment of (–)-shikimic acid as starting material permits the rapid preparation of the polyhydroxylated bromocyclohexene intermediate. (–)-Parasitenone, (+)-epoxydon and its monoactate, (–)-phyllostine and its acetate were readily synthesized via the oxirane ring closure of bromohydrin precursors. Moreover, the key intermediate was successfully extended for the synthesis of the epoxyquinones with a methyl group including (+)-epoformin, (+)-epiepoformin and (−)-theobroxide by sulfonate reduction method for the first time

Background Photosynthesis is a fundamental process that underlies the formation of crop yield, wherein light serves as the driving force and carbon dioxide (CO 2 ) as the raw material. These two factors have a direct influence on the progress and efficiency of photosynthesis in crops. Rapeseed is one of the four major oilseed crops worldwide. Plateau rapeseed has now become a research hotspot. However, the lack of high-yielding rapeseed germplasm resources on the plateau and the highly efficient strategy for screening them severely affect the development of rapeseed industry in plateau. Results In the rapeseed experimental fields located on the plateau (Lhasa, Tibet), we measured abundant sunlight, characterized by an average daily photosynthetically active radiation (PAR) of 1413 μmol m −2 s −1 . In addition, the atmospheric CO 2 concentrations range from 300 to 400 ppm, which is only two-thirds of that in the plain (Chengdu, Sichuan). We found that under different measurement conditions of light intensity and CO 2 concentration, different rapeseed genotypes showed significant differences in leaf photosynthetic efficiency during the seedling stage. Moreover, the rapeseed materials with high photosynthetic efficiency under low CO 2 concentrations rather than high light intensity, exhibited significant advantages in biomass, yield, and oil content when cultivated on the plateau, indicating that the CO 2 is the key environmental factor which limited rapeseed production in plateau. Based on photosynthetic efficiency screening under low CO 2 concentrations, six rapeseed varieties SC3, SC10, SC25, SC27, SC29 and SC37, shown significantly higher yields in plateau environment compared to local control variety were obtained. In addition, the adaptability of rapeseed to plateau was found to be related to the activities of key Calvin cycle enzymes and the accumulation of photosynthetic products. Conclusions This study established a screening strategy for plateau high-yielding rapeseed materials, obtained six varieties which were suitable for plateau cultivation, explored the mechanism of rapeseed response to the plateau environment, and thus provides a feasible strategy for plateau-adapted rapeseed breeding.

BACKGROUND:The transposons of the hAT superfamily are the most widespread transposons ever known. SLEEPER genes encode domesticated transposases from the hAT superfamily, which may have lost their transposable functions during long-term evolution and transformed into host proteins that regulate plant growth and development. RESULTS:This study identified 162 members of the SLEEPER gene family from Brassica napus. These members are widely distributed on 19 chromosomes, mainly in the Cn subgenome, and have promoters with various cis-acting elements related to hormone regulation, abiotic stress, and growth and development regulation. Most of the genes in this family contain similar conserved domains and motifs, and the closer the genes are distributed on evolutionary branches, the more similar their structures are. Transcriptome sequencing performed on tissues at different growth stages from B. napus line 3529 indicated that these genes had different expression patterns, and nearly half of the genes were not detectably expressed in all samples. CONCLUSIONS:This study investigated the gene structure, expression patterns, evolutionary features, and gene localization of the SLEEPER family members to confirm the significance of these genes in the growth of B. napus, providing a reference for the study of transposon domestication and outstanding genetic resources for the genetic improvement of B. napus.

During the COVID-19 pandemic, a significant increased number of masks were used and improperly disposed of. For example, the global monthly consumption of approximately 129 billion masks. Masks, composed of fibrous materials, can readily release microplastics, which may threaten various soil ecosystem components such as plants, animals, microbes, and soil properties. However, the specific effects of mask-derived microplastics on these components remain largely unexplored. Here, we investigated the effects of mask-derived microplastics (grouped by different concentrations: 0, 0.25, 0.5, and 1 % w/w) on soil physicochemical properties, microbial communities, growth performance of lettuce (Lactuca sativa L. var. ramosa Hort.) and earthworm (Eisenia fetida) under laboratory conditions for 80 days. Our findings suggest that mask-derived microplastics reduced soil bulk density while increasing the mean weight diameter of soil aggregates and modifying nutrient levels, including organic matter, potassium, nitrogen, and phosphorus. An increase in the abundance of denitrification bacteria (Rhodanobacteraceae) was also observed. Mask-derived microplastics were found to reduce lettuce germination, and a hormesis effect of low-concentration stimulation and high-concentration inhibition was observed on biomass, chlorophyll, and root activity. While the mortality of earthworms was not significantly affected by the mask-derived microplastics, but their growth was inhibited. Collectively, our results indicate that mask-derived microplastics can substantially impact soil properties, plant growth, and earthworm health, with potential implications for soil ecosystem functionality.

Despite numerous reports on phytoremediation of heavy metals contaminated soil, there are few reports on plant retention of heavy metals in the mining area slope. This study was the first of its kind to explore the cadmium (Cd) retention capacity of the blueberry (Vaccinium ashei Reade). Firstly, we investigated the stress response of blueberry to different soil Cd concentrations (1, 5, 10, 15, 20 mg/kg) to assess its potential for phytoremediation by pot experiments. The results showed that the blueberry biomass exposed to 10 and 15 mg/kg Cd was significantly increased compared with the control (1 mg/kg Cd); the blueberry crown increased by 0.40% and 0.34% in 10 and 15 mg/kg Cd-contaminated soil, respectively, compared with control; the blueberry heigh did not even change significantly in each treatment group; the total chlorophyll content, peroxidase and catalase activity of blueberry were enhanced in 5-20 mg/kg Cd treatments. Furthermore, the Cd contents of blueberry in the root, stem and leaf increased significantly as the Cd concentration of soil increased. We found that more Cd accumulated in blueberry root: the bioaccumulation concentration factor was root > stem > leaf for all groups; the residual-Cd (Cd speciation) in soil increased by 3.83%-411.11% in blueberry-planted versus unplanted groups; blueberry improved the Cd-contaminated soil micro-ecological environment including soil organic matter, available K and P, as well as microbial communities. Then, to investigate the effect of blueberry cultivation on Cd migration, we developed a bioretention model and revealed that soil Cd transport along the model slope was significantly weakened by blueberry cultivation, especially at the bottom of the model. In a word, this research suggests a promising method for the phytoremediation of Cd-contaminated soil and the reduction of Cd migration in mining areas.

生物学实践教学在培养具有创新能力的一流本科人才中起着关键作用.该成果依托"拔尖计划"、生物科学国家级一流本科专业和生物学国家级教学团队,以培养具有家国情怀与科学精神的"创新型生物学一流本科人才"为目标,践行实践育人理念,将川大特色"红色文化"和求真务实、批判创新的科学精神融入实践教学,强化学生思想价值引领和使命担当,加强文献阅读与实验设计训练,开设探究式和开放性实验项目以及多学科交叉和创新创业实践模块,改革实践教学学业评价,构建了厚基础、强综合、促创新的生物学一流本科进阶式实践育人体系,有效引导学生主动性、自主性、创新性实践,学生的创新意识与潜力得到了极大激发.

Abstract Plasmodiophora brassicae is a devastating intracellular pathogen that causes clubroot disease in Brassicaceae plants, which also secrete various effector proteins promoting pathogen colonization and reprogramming host developmental processes. During screening for candidate effector proteins from the Proteome of P. brassicae, we identified a small secreted protein, PbEL04, which can trigger cell death associated with H2O2 accumulation and electrolyte leakage in the nonhost plant Nicotiana benthamiana. This ability to induce cell death was further validated using the recombinant protein produced by Escherichia coli. Moreover, PbEL04-triggered cell death did not require a signal peptide. Structural analysis showed that PbEL04 is a cysteine-rich protein consisting of four tandem EGF-like domains, few of which were homologous to other pathogens. In host plants, PbEL04 could induce cell death in Arabidopsis thaliana protoplasts, and was highly expressed in the process of gall formation. Furthermore, the severity of clubroot disease was greatly reduced in the transgenic lines of PBRA_004448 compared with wild-type Arabidopsis Col-0 after being infected by P. brassicae. Taken together, our study identifies a new secretory protein involved in plant immune response in nonhost and host plants.

Sclerotinia sclerotiorum, a worldwide distributed fungal pathogen, causes serious adverse effects on the yield and seed quality of rapeseed. Polygalacturonase-inhibiting proteins (PGIPs) can protect the cell wall from degradation by pathogen-secreted polygalacturonases (PGs). The present study found several PGIPs from Oryza sativa, especially OsPGIP6 and 3 have much higher inhibitory activities to SsPGs than BnPGIP2 from Brassica napus. Among them, OsPGIP1, 4, 6 can significantly elevate the resistance of transgenic Arabidopsis to S. sclerotiorum. Subsequently, OsPGIP1, 3, 4, 6 were subjected to SSR resistance assay in transgenic rapeseed plants. Among which, OsPGIP6 showed the highest resistance to S. sclerotiorum. At 48 h after detached leaves inoculation, the lesion area of OE-OsPGIP6 rapeseed plants is only 17.93% of the non-transgenic line, and 22.17, 21.32, 52.78, 56.47%, compared to OE-BnPGIP2, OE-OsPGIP1, OE-OsPGIP2, OE-OsPGIP4, respectively. Furthermore, the lesion area of OE-OsPGIP6 reached 10.11% compared to WT at 72 hpi. Also, the lesion length on the stem of OE-OsPGIP6 plants was reduced by 36.83% compared to WT. These results reveal that OsPGIP family, especially OsPGIP6, has a great potential in rapeseed S. sclerotiorum-resistance breeding.

Clubroot disease, caused by Plasmodiophora brassicae, is a devastating disease that results in substantial yield loss in Brassicaceae crops worldwide. In this study, we identified a clubroot disease resistance (CR) Brassica napus, “Kc84R,” which was obtained by mutation breeding. Genetic analysis revealed that the CR trait of “Kc84R” was controlled by a single dominant locus. We used the bulked segregant analysis sequencing (BSA-seq) approach, combined with genetic mapping based on single nucleotide polymorphism (SNP) markers to identify CR loci from the F2 population derived from crossing CR “Kc84R” and clubroot susceptible “855S.” The CR locus was mapped to a region between markers BnSNP14198336 and BnSNP14462201 on the A03 chromosome, and this fragment of 267 kb contained 68 annotated candidate genes. Furthermore, we performed the CR relation screening of candidate genes with the model species Arabidopsis. An ERF family transcriptional activator, BnERF034, was identified to be associated with the CR, and the corresponding Arabidopsis homozygous knockout mutants exhibited more pronounced resistance compared with the wild-type Col-0 and the transgenic lines of BnERF034 in response to P. brassicae infection. Additionally, the expression analysis between resistant and susceptible materials indicated that BnERF034 was identified to be the most likely CR candidate for the resistance in Kc84R. To conclude, this study reveals a novel gene responsible for CR. Further analysis of BnERF034 may reveal the molecular mechanisms underlying the CR of plants and provide a theoretical basis for Brassicaceae resistance breeding.

An efficient synthesis of ECH, epoxyquinols A and B, and two bioactive analogs EqM and RKTS-33 has been completed starting from (-)-shikimic acid. Rapid establishment of the desired epoxyquinol core is facilitated through a key allylic oxidation with high stereoselectivity, which is achieved by fine tuning the cyclohexene substrate structure and reaction conditions.

为了探究寄主根系分泌物中对根肿菌休眠孢子萌发具有重要作用的代谢物，本研究首先测试了甘蓝型油菜不同根肿病抗性材料的根系分泌物对休眠孢子萌发的诱导能力，发现易感材料根系分泌物处理组的萌发率显著高于抗性材料处理组.进一步采用非靶向液相色谱-质谱联用代谢物分析法检测了抗病材料和易感材料的根系分泌物，在负离子（ESI-）模式下鉴定出次级代谢产物1079个，在正离子（ESI+）模式下鉴定出次级代谢产物1257个，其中差异代谢物分别为662和722个.选取部分差异较大的代谢物进行验证，结果表明，胸腺嘧啶，2′-脱氧尿苷，L-异亮氨酸，葫芦巴碱，磷酸吡哆醛，香豆素，D-来苏糖和穗花杉双黄酮等对休眠孢子萌发具有显著促进作用，继而影响根肿病的发生.

A new synthetic strategy for C7-carbasugars is developed via an intramolecular Morita-Baylis-Hillman reaction, in which a substituted dial precursor prepared from D-mannose cyclizes smoothly in the presence of DMAP to afford polyhydroxylated cyclohex-1-enecarbaldehyde with good yield. By employment of the cyclization products as key intermediates, the first syntheses of carbasugar ester 1 and epicorepoxydon A, as well as practical syntheses of epoxydines B and C, (-)-MK7607, (-)-streptol, and (-)-gabosine E are achieved.

In this study, we aimed to investigate the biopesticide activity of a novel fungal strain Bjerkandera adusta BK-1. The in vitro inhibitory potential of BK-1 against six species of identified phytopathogenic fungi was evaluated using a dual culture assay. In addition, in-planta treatment with BK-1 as a fungicide significantly reduced plant disease symptoms, such as grey mould, brown spot, and early blight disease. Furthermore, the colonisation ability of BK-1 in soil and leaves was also found to be stable. Overall, BK-1 has practical value as a novel, promising broad-spectrum biocontrol agent against multiple plant fungal diseases.