In this investigation, 396 endophytic bacterial strains from six indigenous medicinal plant species within the Xinjiang Tumor Peak National Nature Reserve were subjected to screening. The strain MR4 emerged as a noteworthy contender, demonstrating pronounced biocontrol capabilities coupled with exceptional cold tolerance. Through morphological scrutiny and comprehensive genomic sequencing, MR4 was identified as Bacillus amyloliquefaciens. Antagonistic assays revealed MR4’s efficacy in suppressing the causative agents of cotton wilt and verticillium wilt, achieving inhibition rates surpassing 50%. Analyses, underpinned by PCR methodologies, indicated MR4’s capacity to biosynthesize a minimum of eight distinct antimicrobial agents. The whole-genome sequencing data indicated that B. amyloliquefaciens MR4 had the genome size and GC content of 4,017,872 bp and 47.14%, respectively, and 4191 coding genes were identified. The genome consists of a single chromosome and one plasmid. Moreover, it was augmented by annotations from various databases, including GO, KEGG, and COG. The pathogenicity of MR4 undergoes evaluation, while predictions concerning MR4’s secondary metabolites have disclosed gene clusters for 13 varieties of these compounds, with particular emphasis on surfactins and fengycin. Comparative analyses with four paradigmatic strains shed light on MR4’s genomic composition and its phylogenetic lineage within the Bacillus genus. The genomic data pertaining to MR4 have been duly submitted to the NCBI GenBank, bearing the accession numbers CP146236 (Chr1) and CP146237 (plas1). This study endeavors to furnish potent microbial resources for the biocontrol and enhancement of plant growth, thereby providing a theoretical groundwork for MR4’s agronomic utilization. Graphical Abstract

The plant pathogenic fungus Cytospora is notoriously known for causing woody plant canker diseases, resulting in substantial economic losses to biological forests and fruit trees worldwide. Despite their strong negative ecological impact, the existing and prospective distribution patterns of these plant pathogens in China, according to climate change, have received little attention. In this study, we chose three widely dispersed and seriously damaging species, namely, Cytospora chrysosperma, Cytospora mali, and Cytospora nivea, which are the most common species that damage the Juglans regia, Malus domestica, Eucalyptus, Pyrus sinkiangensis, Populus spp., and Salix spp. in China. We utilized ecological niche modeling to forecast their regional distribution in China under four climate change scenarios (present, SSP 126, SSP 370, and SSP 585). The results show that temperature-related climate factors limit the current distribution ranges of the three species. Currently, the three studied species are highly suitable for northeast, northwest, north, and southwest China. Under future climate scenarios, the distribution ranges of the three species are projected to increase, and the centers of the adequate distribution areas of the three species are expected to shift to high-latitude regions. The three species coexist in China, primarily in the northwest and north regions. The ecological niches of C. chrysosperma and C. nivea are more similar. The distribution range of C. mali can reach the warmer and wetter eastern region, whereas C. chrysosperma and C. nivea are primarily found in drought-prone areas with little rainfall. Our findings can help farmers and planners develop methods to avoid the spread of Cytospora spp. and calculate the costs of applying pesticides to reduce contamination and boost yields.

Years of outbreaks of woody canker (Cryptosphaeria pullmanensis) in the United States, Iran, and China have resulted in massive economic losses to biological forests and fruit trees. However, only limited information is available on their distribution, and their habitat requirements have not been well evaluated due to a lack of research. In recent years, scientists have utilized the MaxEnt model to estimate the effect of global temperature and specific environmental conditions on species distribution. Using occurrence and high resolution ecological data, we predicted the spatiotemporal distribution of C. pullmanensis under twelve climate change scenarios by applying the MaxEnt model. We identified climatic factors, geography, soil, and land cover that shape their distribution range and determined shifts in their habitat range. Then, we measured the suitable habitat area, the ratio of change in the area of suitable habitat, the expansion and shrinkage of maps under climate change, the direction and distance of range changes from the present to the end of the twenty-first century, and the effect of environmental variables. C. pullmanensis is mostly widespread in high-suitability regions in northwestern China, the majority of Iran, Afghanistan, and Turkey, northern Chile, southwestern Argentina, and the west coast of California in the United States. Under future climatic conditions, climate changes of varied intensities favored the expansion of suitable habitats for C. pullmanensis in China. However, appropriate land areas are diminishing globally. The trend in migration is toward latitudes and elevations that are higher. The estimated area of possible suitability shifted eastward in China. The results of the present study are valuable not only for countries such as Morocco, Spain, Chile, Turkey, Kazakhstan, etc., where the infection has not yet fully spread or been established, but also for nations where the species has been discovered. Authorities should take steps to reduce greenhouse gas emissions in order to restrict the spread of C. pullmanensis. Countries with highly appropriate locations should increase their surveillance, risk assessment, and response capabilities.

Fragrant pear canker, caused by Cytospora pyri, is a major branch disease that reduces the productivity and longevity of Korla fragrant pear orchards in Xinjiang, China. During infection and lesion expansion in woody tissues, C. pyri must breach the host cell wall barrier, in which pectin degradation plays a central role by weakening intercellular adhesion and disrupting tissue integrity. Members of glycoside hydrolase family 28 (GH28), represented mainly by polygalacturonases and other pectin-degrading enzymes, are closely involved in fungal invasion and colonization. However, the composition and virulence-related functions of this gene family encoding for these enzymes in C. pyri remain unclear. In this study, GH28 genes were systematically identified and comparatively analyzed in C. pyri and closely related Cytospora species. Infection-stage expression profiling and functional validation were then performed to assess their roles in pathogenicity. A total of 73 GH28 genes were identified across five Cytospora species, including 15 in C. pyri. Most C. pyri GH28 proteins were predicted to be acidic, hydrophilic, extracellularly secreted proteins carrying conserved motifs. Phylogenetic analysis showed that C. pyri GH28 members were closely related to homologs from C. mali. Genomic distribution analysis revealed that these genes were dispersed across multiple scaffolds, with no obvious tandem duplication events. RT-qPCR analysis showed that all seven candidate GH28 genes were induced during infection of fragrant pear branches, with VP1G_08835 and VP1G_03209 exhibiting strong expression responses at 6 dpi. Functional validation further showed that deletion of VP1G_08835 impaired vegetative growth and reduced lesion length on detached pear branches by 26.62% compared with the wild type, whereas complementation restored these phenotypes. These findings demonstrate that GH28 genes participate in C. pyri infection and identify VP1G_08835 as an important GH28 member required for normal growth and contributing to virulence.

Fragrant pear canker, caused by Cytospora pyri, is a major branch disease that reduces the productivity and longevity of Korla fragrant pear orchards in Xinjiang, China. During infection and lesion expansion in woody tissues, C. pyri must breach the host cell wall barrier, in which pectin degradation plays a central role by weakening intercellular adhesion and disrupting tissue integrity. Members of glycoside hydrolase family 28 (GH28), represented mainly by polygalacturonases and other pectin-degrading enzymes, are closely involved in fungal invasion and colonization. However, the composition and virulence-related functions of this gene family in C. pyri remain unclear. In this study, GH28 genes were systematically identified and comparatively analyzed in C. pyri and closely related Cytospora species. Infection-stage expression profiling and functional validation were then performed to assess their roles in pathogenicity. A total of 73 GH28 genes were identified across five Cytospora species, including 15 in C. pyri. Most C. pyri GH28 proteins were predicted to be acidic, hydrophilic, extracellularly secreted proteins carrying conserved motifs. Phylogenetic analysis showed that C. pyri GH28 members were closely related to homologs from C. mali. Genomic distribution analysis revealed that these genes were dispersed across multiple scaffolds, with no obvious tandem duplication events. RT-qPCR analysis showed that all seven candidate GH28 genes were induced during infection of fragrant pear branches, with VP1G_08835 and VP1G_03209 exhibiting strong expression responses at 6 dpi. Functional validation further showed that deletion of VP1G_08835 impaired vegetative growth and reduced lesion length on detached pear branches by 26.62% compared with the wild type, whereas complementation restored these phenotypes. These findings demonstrate that GH28 genes participate in C. pyri infection and identify VP1G_08835 as an important GH28 member required for normal growth and full virulence.