Controlling bacterial spot of stone fruit disease has been a key target in peach planting areas throughout the world. Accurate warning of the risks of infection is crucial for determining spraying time. A bacterial spot model applicable to peach planting areas in China has not yet been built. We optimized and evaluated a model developed for bacterial spot of stone fruit disease in Spain, adapting it for two cultivars and locations in China. Both the original and optimized models performed well in estimating the incidence of bacterial spot in both cultivars and two locations during the eight evaluated years, obtaining a correlation coefficient (R2) of 0.88, an average mean absolute error of 3.19, an average root mean square error of 3.34, and a slight overestimation (coefficient of residual mass = 0.098). Wetness duration and mean temperature during the period play significant roles in the model; a shorter wetness duration resulted in a lower incidence in Beijing in 2023 compared with other years. This study demonstrates that the model can be an effective tool for determining the warning of the incidence of bacterial spot of stone fruit disease and helping peach growers in China control this disease.

Grapevine Botryosphaeria dieback (GBD), caused by Botryosphaeriaceae species, is an important grapevine trunk disease that poses a threat to grape yield and quality in global viticultural regions. Pathogen diagnosis at the species level using morphological methods is difficult and time-consuming. Therefore, this study aimed to develop a rapid and accurate detection method for the pathogens causing GBD. Recombinase polymerase amplification (RPA) with CRISPR/Cas12a cleavage was combined for detecting pathogens associated with GBD, and lateral flow dipsticks were employed to monitor the outcomes. Based on the beta-tubulin sequences of Botryosphaeriaceae and their related species, specific RPA primers and CRISPR/Cas12a CrRNA were designed and subsequently selected for specifically detecting pathogens associated with GBD. Under optimized reaction conditions and systems, the developed RPA/CRISPR-Cas12a detection system specifically detected Botryosphaeriaceae species within 30 min of RPA and 25 min of CRISPR/Cas12a reactions at 37 degrees C. Specificity tests showed that specific fragments were amplified with the RPA primers in the DNA of six Botryosphaeriaceae species found in China, while none of the fragments were amplified in the other 22 nontarget fungal pathogen species of grapevine. The detection sensitivity of this method was 1 pg/mu l, which is equal to that of real-time PCR. In summary, our method is simple to perform, produces visual results, does not rely on expensive equipment, and therefore possesses high practical value, providing an efficient and robust detection platform to accelerate the field detection of pathogens associated with GBD.

Endophytic bacteria within plant tissues play crucial roles in plant health, stress tolerance, and contribute to the metabolite diversity of host plants. Cannabis sativa L. is an economically significant plant, with industrial hemp (IH) and medicinal Cannabis (MC) being the two main cultivars. However, the composition and functional traits of their endophytic bacterial communities in roots and leaves are not well understood. In this study, DNA metabarcode sequencing were employed to compare the bacterial communities between IH and MC. Significant differences were observed in the root and leaf niches. IH roots were enriched with stress-tolerant bacteria, while MC roots showed higher levels of biofilm-forming bacteria. In leaves, differences were even more pronounced, particularly in the abundance of Gram-negative bacteria, potential pathogens, stress-tolerant bacteria, and biofilm-forming bacteria. PICRUSt2 functional predictions revealed differences in nitrogen metabolism and secondary metabolite biosynthesis pathways in different cultivars and niches, while FAPROTAX analysis highlighted variations in carbon, nitrogen, and sulfur cycling functions. These findings underscore the distinct roles of bacterial communities in regulating plant health, stress responses, and metabolic processes in different niches and cultivars, providing insights for improving cultivation practices and plant resilience.

A new species of false truffle was discovered in Zixishan Mountain, Yunnan Province, China. Through morphological examination and multigene phylogenetic analysis based on ITS and nrLSU sequences of the genus Gautieria, the species is described as Gautieria zixishanensis sp. nov., belonging to Gautieria sect. Hymenogastroides. This new species is characterized by its pseudoperidial basidiomata, with a basal depression connected to abundant white basal rhizomorphs, an intact tomentose pseudoperidium that remains attached when mature, the absence of foveate-porate structures and ridges, and light golden-brown basidiospores with longitudinal ridges, measuring 17–22 μm in length.

Peach (Prunus persica L.) is one of the most important and oldest stone fruits grown in China. Even though P. persica is one of the most commonly grown stone fruits in China, little is known about the biodiversity of microfungi associated with peach branch diseases. In the present study, samples were collected from a wide range of peach growing areas in China, and fungal pathogens associated with peach branch diseases were isolated. In total, 85 isolates were obtained and further classified into nine genera and 10 species. Most of the isolates belonged to Botryosphaeriaceae (46), including Botryosphaeria, Diplodia, Neofusicoccum, Phaeobotryon, and Lasiodiplodia species; Ascochyta, Didymella, and Nothophoma species representing Didymellaceae were also identified. Herein, we introduce Ascochyta prunus and Lasiodiplodia pruni as novel species. In addition, we report the first records of Nothophoma pruni, Neofusicoccum occulatum, and Phaeobotryon rhois on peach worldwide, and Didymella glomerata, Nothophoma quercina, and Phaeoacremonium scolyti are the first records from China. This research is the first comprehensive investigation to explore the microfungi associated with peach branch disease in China. Future studies are necessary to understand the pathogenicity and disease epidemiology of these identified species.

Peach (Prunus persica) is widely cultivated in China, but fungal diseases, particularly Cytospora canker, significantly impact tree health, reducing fruit yield and economic value. This disease mainly weakens tree branches and trunks, sometimes leading to tree death. There are no updated studies on the diversity of Cytospora species associated with peach Cytospora canker in northern China. To determine the Cytospora species associated with this disease, we surveyed five provinces from 2022 to 2023, collecting 72 disease samples with symptoms including branches with black fruiting bodies, cankers, cracking, dieback, and gummosis. Through morphology and multi-loci phylogeny, 127 isolates were identified into four known (C. ailanthicola, C. erumpens, C. leucostoma, and C. leucosperma) and two previously undescribed species (C. gansuensis sp. nov. and C. qinanensis sp. nov.). Cytospora leucostoma (73.60%) was the most abundant. Pathogenicity tests indicated that except for C. ailanthicola, all other species were pathogenic to peach, with C. erumpens being the most aggressive. This study is the first to report the novel host association of C. erumpens on peaches globally and represents the first comprehensive investigation of Cytospora species associated with canker diseases in the main peach production area in northern China, offering a foundation for developing effective disease management strategies.

Peach (Prunus persica L.) is one of the most important and oldest stone fruits grown in China. Though Diaporthe species have more commonly been reported as plant pathogens, endophytes and saprophytes with a wide range of plant hosts, little is known about the Diaporthe species associated with peach trunk diseases in China. In the present study, forty-four Diaporthe isolates were obtained from trees with peach branch canker, shoot blight and gummosis symptoms in four provinces in China. Based on a combination of morphology and multi-locus sequence analysis of the rDNA internal transcribed spacer region (ITS), calmodulin (cal), translation elongation factor 1-α (tef1) and β-tubulin (tub2), these Diaporthe isolates were assigned to four species. Detailed descriptions and illustrations of all of the species, D. arecae, D. caulivora, D. discoidispora and D. eres, are provided. This study further reports the first host association of D. caulivora and D. discoidispora on peaches worldwide. The pathogenicity experiment results revealed that D. arecae was the most aggressive species, whereas D. discoidispora was the least aggressive on detached peach shoots. This study provides new insights into the fungi associated with peach trunk diseases in China, and the results of this study may help to facilitate routine diagnosis and planning of suitable plant disease management strategies.

Fusarium oxysporum f. sp. cucumerinum (Foc) is a prominent pathogen that adversely affects cucumber (Cucumis sativus) production. In the pathogen's parasitic lifestyle, the pathogenesis and virulence evolution may be regulated by lysine acetylation, as demonstrated in many living organisms. However, its specific function in Foc remains poorly understood. In this study, the acetylome profiles of a mild virulence strain (foc-3b) and its derived virulence-enhanced strain (Ra-4) were analyzed before and post-inoculation on cucumber plants. In total, 10,664 acetylation sites were identified corresponding to 3874 proteins, and 45 conserved acetylation motifs were detected. Through comparison of the acetylomes, numerous differentially lysine-acetylated proteins were enriched in energy metabolism and protein processing processes, indicating the critical role of lysine acetylation during the transition from the saprotrophic lifestyle to the parasitic lifestyle. Comparative acetylome analyses on the two virulence-differentiated strains revealed that several differentially lysine-acetylated proteins were involved in pathways of defense response and energy metabolism. Ra-4 showed enhanced energy metabolism compared to foc-3b. This indicates that robust metabolic activity is required to achieve high virulence and facilitating adaptive evolution. Additionally, faster host responses are supported by an ample energy supply enhancing virulence. Thus, lysine acetylation plays a crucial role in the pathogenesis and virulence evolution of Foc.

2019年—2020年在北京地区桃园病害调研普查时发现一种桃树病害的新发症状-新叶坏死,主要症状表现为当年新生枝条顶端新叶和生长点腐烂坏死.为明确这种新叶坏死症状是否由病原菌侵染引起,从北京平谷2个乡镇3个桃园采集35份病梢样品,经病样组织分离和菌株纯化,选取12个代表性菌株进行形态学鉴定、系统进化分析以及致病性测定.结果显示,通过形态学鉴定和多基因(ITS,Alta1,gpd)系统发育分析,以上分离株均鉴定为链格孢Alternaria alternata;3株代表性菌株的致病性测定验证了 A.altemata是引起新叶坏死症状的病原菌,并且该病原菌也能导致桃枝条和果实发病,产生黑斑病症状.这是首次报道A.altemata除了引起桃果实黑斑症状之外,还可以引起桃树新叶坏死症状,结果进一步丰富了链格孢侵染桃树的症状多样性,为链格孢引起的病害的整体防控提供了理论基础.

葡萄顶枯病(Eutypa dieback)是世界各地许多葡萄生产地区发生最具破坏性的病害之一,目前广泛分布在美国、澳大利亚、加拿大、中国等28个国家.葡萄顶枯病由多种病原菌侵染引起,防治难度较大.目前,文献主要报道了该病害的发生规律,以及针对致病性最强、也是最常见的致病菌Eutypa lata的防治研究.通过综述该病害的症状、病原、发生规律和防治措施,为国内该病害的防治提供新思路.

Botrytis cinerea, the causal agent of gray mold, is one of the most destructive pathogens of cherry tomatoes, causing fruit decay and economic loss. Fludioxonil is an effective fungicide widely used for crop protection and is effective against tomato gray mold. The emergence of fungicide-resistant strains has made the control of B. cinerea more difficult. While the genome of B. cinerea is available, there are few reports regarding the large-scale functional annotation of the genome using expressed genes derived from transcriptomes, and the mechanism(s) underlying such fludioxonil resistance remain unclear. The present study prepared RNA-sequencing (RNA-seq) libraries for three B. cinerea strains (two highly resistant (LR and FR) versus one highly sensitive (S) to fludioxonil), with and without fludioxonil treatment, to identify fludioxonil responsive genes that associated to fungicide resistance. Functional enrichment analysis identified nine resistance related DEGs in the fludioxonil-induced LR and FR transcriptome that were simultaneously up-regulated, and seven resistance related DEGs down-regulated. These included adenosine triphosphate (ATP)-binding cassette (ABC) transporter-encoding genes, major facilitator superfamily (MFS) transporter-encoding genes, and the high-osmolarity glycerol (HOG) pathway homologues or related genes. The expression patterns of twelve out of the sixteen fludioxonil-responsive genes, obtained from the RNA-sequence data sets, were validated using quantitative real-time PCR (qRT-PCR). Based on RNA-sequence analysis, it was found that hybrid histidine kinase, fungal HHKs, such as BOS1, BcHHK2, and BcHHK17, probably involved in the fludioxonil resistance of B. cinerea, in addition, a number of ABC and MFS transporter genes that were not reported before, such as BcATRO, BMR1, BMR3, BcNMT1, BcAMF1, BcTOP1, BcVBA2, and BcYHK8, were differentially expressed in the fludioxonil-resistant strains, indicating that overexpression of these efflux transporters located in the plasma membranes may associate with the fludioxonil resistance mechanism of B. cinerea. All together, these lines of evidence allowed us to draw a general portrait of the anti-fludioxonil mechanisms for B. cinerea, and the assembled and annotated transcriptome data provide valuable genomic resources for further study of the molecular mechanisms of B. cinerea resistance to fludioxonil.

The mechanical properties of guard cells have major effects on stomatal functioning. Reinforced stiffness in the stomatal polar regions was recently proposed to play an important role in stomatal function, but the underlying molecular mechanisms remain elusive. Here, we used genetic and biochemical approaches in poplar (Populus spp.) to show that the transcription factor MYB156 controls pectic homogalacturonan-based polar stiffening through the downregulation of the gene encoding pectin methylesterase 6 (PME6). Loss of MYB156 increased the polar stiffness of stomata, thereby enhancing stomatal dynamics and response speed to various stimuli. In contrast, overexpression of MYB156 resulted in decreased polar stiffness and impaired stomatal dynamics, accompanied by smaller leaves. Polar stiffening functions in guard cell dynamics in response to changing environmental conditions by maintaining normal stomatal morphology during stomatal movement. Our study revealed the structure-function relationship of the cell wall of guard cells in stomatal dynamics, providing an important means for improving the stomatal performance and drought tolerance of plants.

The LysM proteins have been reported to be important for the virulence and host immunity suppression in herbaceous plant pathogens, whereas far less information is documented in the woody plant pathogen Lasiodiplodia theobromae. To investigate the functional mechanism of LysM protein in L. theobromae, one gene LtScp1 was cloned and characterized detailedly in the current study. Transcription profiling revealed that LtScp1 was highly expressed at the infectious stages. Compared to wild type, overexpression and silencing of LtScp1 in L. theobromae led to significantly increased and decreased lesion areas, respectively. Moreover, LtScp1 was determined to be a secreted protein via a yeast signal peptide trapping system. Interestingly, LtScp1 was confirmed to be modified by the N-glycosylation, which is necessary for the homodimerization of LtScp1 molecules. Furthermore, it was found that LtScp1 interacted with the grapevine chitinase VvChi4 and interfered the ability of VvChi4 to bind chitin. Collectively, these results suggest that LtScp1 functions as a virulence factor to protect the fungus from degradation during the infection.

Dendrobium officinale is an important traditional Chinese medicinal herb, and the stem tissue is the main medicinal that is harvested from D. officinale. Recently, the first viroid was identified from D. officinale in China, and it has been named Dendrobium viroid (DVd). Whether DVd interferes with metabolic pathways in dendrobium plants and affects the medicinal value of the host is unknown. In this study, metabolomics data from stem tissues supported by transcriptome studies were used to investigate how metabolism modulate of D. officinale is altered by DVd infection. Our results show that metabolism of D. officinale is reprogrammed in many ways during DVd infection, and this is reflected by significant changes in the levels of flavonoids, alkaloids, and phenolic acids. Furthermore, we found that DVd infection significantly decreased the accumulation of flavonoids and alkaloid metabolites in infected stems, and the decreases in these metabolites appears to affect the medicinal components of the infected plants, weakening the host antiviral immune response as well. Conversely, phenolic acids occupy a larger proportion of the up-regulated metabolites from DVd infection in comparison with the mock-inoculated control, and the increase in the total phenolic acids may reflect the activation of the pathogen defense response in D. officinale. Taken together, our results provide an interesting overview and give a better understanding of the relationship between metabolism and DVd infection in the orchid D. officinale.

Objective Porphyromonas gingivalis ( Pg ) plays a critical role in the occurrence and development of atherosclerosis. Lipopolysaccharide from Pg ( Pg -LPS) could lead to pyroptosis of vascular smooth muscle cells (VSMCs) and induce instability of atherosclerotic plaque. Therefore, pyroptosis of VSMCs could promote the process of atherosclerosis. However, the exact mechanism of Pg -LPS-induced pyroptosis of VSMCs is unclear. Methods We determined pyroptosis and expression of interleukin (IL)-1β and IL-18 in VSMCs using 4′,6-diamidino-2-phenylindole staining and ELISA after stimulation by Pg -LPS. We established a knockdown plasmid containing the circular (circ)RNA PPP1CC and transfected it into VSMCs. Luciferase assays were performed to reveal the association between microRNAs miR-103a-3p and miR-107 and circRNA PPP1CC. Results Stimulation of Pg -LPS led to pyroptosis of VSMCs. Knockdown of circRNA PPP1CC relieved the Pg -LPS-induced pyroptosis of VSMCs and suppressed the expression of HMGB1 , TLR9 , AIM2 , and cleaved caspase-1. Luciferase assays showed that PPP1CC directly targeted and competitively adsorbed miR-103a-3p and miR-107, weakening the inhibitory effect of these microRNAs on the expression of HMGB1 . Conclusion Knockdown of circRNA PPP1CC relieved Pg -LPS-induced pyroptosis of VSMCs. Pyroptosis of VSMCs appears to promote atherosclerosis and may represent a novel therapeutic target for its treatment. Keywords Pyroptosis , , , lipopolysaccharide , -LPS , vascular smooth muscle cells , circRNA PPP1CC , HMGB1/TLR9/AIM2 pathway

为筛选生产中防治韭菜灰霉病的适用药剂,采用菌丝生长速率法测定了9种非化学杀菌剂对韭菜灰霉病病菌的室内毒力,发现10％多抗霉素B可湿性粉剂和100亿CFU/g枯草芽孢杆菌可湿性粉剂的毒力最强,EC50值分别为0.004 1、0.007 6 μg/mL;0.5％大黄素甲醚水剂和3亿CFU/g哈茨木霉菌可湿性粉剂的毒力较弱.田间药效试验验证,10％多抗霉素B可湿性粉剂、100亿CFU/g枯草芽孢杆菌可湿性粉剂常规用量处理的防效分别为67.60％和61.01％,适用于田间韭菜灰霉病的防治.

重组酶介导的等温扩增技术(Recombinase polymerase amplification,RPA)是一种新型的恒温核酸体外扩增技术,与传统PCR和其他等温扩增技术相比较,具有对仪器依赖性低、核酸扩增效率高的优势,适合于现场快速检测,已在微生物检测领域有了较广泛的应用.本文介绍了RPA的技术原理、产物检测方法以及技术条件的摸索优化,并概述了近年来此技术在植物病原检测领域的应用情况,展望了今后RPA技术的发展方向,以期为新兴技术在植物病原检测中的进一步应用与改进研究提供参考.

[目的]由葡萄座腔菌属(Botryosphaeria)真菌引起的溃疡病是葡萄生产上的重要病害之一,在国内多个葡萄产区发生,严重威胁葡萄的产量及品质.本研究对葡萄溃疡病菌(Lasiodiplodia theobromae)中一个假定外泌蛋白LtGH61A进行功能分析,为进一步解析葡萄溃疡病菌的致病机理及病害防控提供理论依据.[方法]通过Signa1P 4.0预测LtGH61A蛋白的信号肽;氨基酸序列同源比对结合基因功能注释,预测LtGH61A蛋白的功能;通过酵母互补试验分析LtGH61A蛋白的外泌特性;采用实时荧光定量PCR (qRT-PCR)分析LtGH61A在病原菌营养菌丝及侵染寄主不同阶段的表达量;借助RNA干涉(RNAi)对LtGH61A进行表达抑制;通过葡萄枝干离体接种试验,分析LtGH61A蛋白对葡萄溃疡病菌致病力的影响.通过比较菌落直径,分析LtGH61A蛋白对葡萄溃疡病菌菌丝生长速率的影响.[结果]信号肽预测表明LtGH61A蛋白N端具有一个长度为1 8个氨基酸的信号肽;基因功能注释推定LtGH61A的编码产物属于糖苷水解酶61 (GH61)家族,能酶解纤维素类物质;互补蔗糖酶外泌缺陷型酵母YTK12结果表明,LtGH61A蛋白的信号肽具有外泌活性,能够引导酵母YTK12蔗糖酶的外泌;与营养菌丝阶段相比,LtGH61A的表达量在病原菌侵染阶段显著升高,并且在接种后48 h高达营养菌丝阶段的19倍;通过RNAi试验及qRT-PCR验证,获得了2个LtGH61A表达量明显降低的阳性转化子,分别命名为RNAi-LtGH61A1和RNAi-LtGH61A2;葡萄枝干离体接种试验结果显示,与野生型CSS-01s相比,RNAi-LtGH61A1和RNAi-LtGH61A2转化子在葡萄枝干形成的病斑长度显著变短,约为野生型CSS-01s的55％,表明LtGH61A影响葡萄溃疡病菌的致病力;菌落直径比较显示,与野生型CSS-01s相比,RNAi-LtGH61A1和RNAi-LtGH61A2转化子的菌落直径变小,约为野生型85％,表明LtGH61A影响葡萄溃疡病菌的菌丝生长速率.[结论]LtGH61A影响葡萄溃疡病菌的致病力及生长速率;LtGH61A蛋白能够分泌至胞外;LtGH61A在病原菌侵染阶段的表达量显著升高,推测其通过发挥自身酶活功能,破坏寄主植物组织,从而促进病原菌的侵染.