Journal of Plant Pathology最新文献

An effective tool for discovering differentially expressed genes (DEGs) related to late blight (LB) resistance is the transcriptome sequencing of potatoes. The aim of this study was to compare transcriptome expression analysis in incompatible and compatible interactions via high-throughput sequencing. Furthermore, we performed a bioinformatics analysis to screen a large number of specific transcription factors (TFs) and DEGs linked to Phytophthora infestans infection. Two locally cultivated potato varieties were chosen from evaluation assays conducted in two consecutive seasons and based on the disease severity (DS) values. These varieties were the highly resistant Jelly (HR) to P. infestans and the moderately susceptible Annabelle (MS). Ribonucleic acid-sequencing (RNA-seq) was achieved for the two varieties with their controls through the BGISEQ-500 sequencing platform. The RNA-seq analysis identified P. infestans-responsive genes and their expression in potatoes. The mechanism of the response of these cultivars to the P. infestans pathogen by TFs and DEG genes, which play an important role in defense response, was investigated. The Gene Ontology (GO) analysis classified 46,248 unigenes in the HR and 26,921 unigenes in MS into the following three categories: biological process, cellular component, and molecular functions. More genes were responsible for the cellular component category, biological process, and molecular functions in HR compared to MS. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the significantly enriched DEGs were included in the plant–pathogen interaction, biosynthesis of secondary metabolites, and ribosome. In addition, 1874 transcription factor genes belonging to 85 families were indicated in the DEGs, of which MYB and AP2-EREBP genes were the most abundant. Besides, multiple genes related to LB resistance showed differential expression during infection. It also sheds light on the molecular mechanisms behind potato resistance to P. infestans infection.

The genetic diversity of 52 Erwinia amylovora isolates from pome fruit trees with fire blight in Central and Eastern Georgia from the years 2020–2022 was examined using specific PCR and genotyping of CRISPR repeat regions 1 and 2. The analysis identified three distinct genotypes: (A, a, α), matching historical Western European strains; (A, z, α), distinctive for Georgia and differing by a three-spacer deletion in CRR2 (2034–2036); as well as novel genotype (A, ä, α), which was not observed previously. Genotypes (A, a, α) and (A, z, α) were found to coexist geographically in all four regions investigated, whereas genotype (A, ä, α) was reported only in one case in the region of Kvemo Kartli. On separate instances, multiple genotypes were detected even within the same orchard or tree, illustrating the complex genetic landscape of E. amylovora in the country.

The connection between the traditional Chinese medicinal herb Bletilla striata and microorganisms is still not well understood. Our study aimed to uncover the structure and diversity of the fungal and bacterial communities associated with B. striata. Bioinformatics, biocontrol and biochemical experiments were carried out. In terms of relative abundance of the top 15 phyla of microbial species, tenericutes in stems (58.74%) and roots (39.36%) showed the highest relative abundance, while cyanobacteria in leaves presented the most (64.53%). At the genus level, there were 32 genera of bacteria detected in three tissues. Sphingomonas showed relative abundances in leaves (41.54%) and stems (22.68%), while Paraburkholderia showed the highest relative abundance in roots (20.87%). In contrast, the dominant genera of the fungi were Melampsora (28.55–43.61%) and Cryptococcus (6.1-25.56%) among the top 15 genera of fungi species. Twenty microorganisms were obtained from roots, stems, and leaves and isolated, which also confirmed the results of the bioinformatics analysis. The isolated Bacillus velezensis exhibits the capability to enhance both the growth and nutrient accumulation of B. striata. Additionally, B. velezensis, along with its fermentation products, contributes to the improvement of antioxidant enzyme activity. Notably, there are variations in the species and abundance of microflora present in the leaves, stems, and roots of B. striata at both the phylum and genus levels. The components of the microbial flora that were isolated and identified align with the results obtained from bioinformatic analyses. It is noteworthy that B. velezensis exerts a positive impact on the increase in yield of B. striata. This work provides important insights into B. striata-associated microorganisms that are essential for promoting growth and disease resistance by revealing the complex structure and variety of fungal and bacterial communities.

In this study, the chemical compositions of rosemary (Rosmarinus officinalis Spenn.) and sweet marjoram (Origanum majorana L.) essential oils, both individually and in various blend ratios, were investigated by using Gas Chromatography-Mass Spectrometry. Their antifungal activities were also determined against the potato rubbery rot disease agent, Geotrichum candidum, under in vitro and in vivo conditions. Camphor (20.69%) and terpinen-4-ol (35.13%) were determined as primary constituents in rosemary and sweet marjoram essential oils, respectively. Sweet marjoram and rosemary essential oils completely inhibited mycelial growth of G. candidum at 55.0 and 65.0 µL/Petri concentrations, respectively. Essential oils at these concentrations were found as fungicidal. Notably, a synergistic fungicidal antifungal effects were also observed in essential oil blends. Blend of sweet marjoram and rosemary essential oil in a 3:1 ratio (O₇₅R₂₅) significantly enhanced antifungal activity at the relatively lower concentration (45.0 µL/Petri). Microscopic observations revealed structural deformations in exposed hyphae, including cytoplasmic coagulation and vacuolization. Essential oil blend (O₇₅R₂₅), sweet marjoram and rosemary essential oils completely inhibited the disease lesion caused by G. candidum on potato tubers at concentrations of 100.0, 125.0, and 150.0 µL/L air, respectively. These findings emphasized that essential oil blends of rosemary and sweet marjoram have synergistic antifungal potential and can be used as effective biofungicides against plant fungal diseases.