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BACKGROUND: The pinewood nematode (Bursaphelenchus xylophilus) causes severe damage to pine trees. The nematophagous fungus, Esteya vermicola, exhibits considerable promise in the biological control of Bursaphelenchus xylophilus due to its infectivity. Notably, the lunate conidia produced by E. vermicola can infect Bursaphelenchus xylophilus. In the study, we aim to investigate the genes involved in the formation of the lunate conidia of E. vermicola CBS115803. RESULTS: Esteya vermicola CBS115803 yielded 95% lunate conidia on the complete medium (CM) and 86% bacilloid conidia on the minimal medium (MM). Transcriptomic analysis of conidia from both media revealed a significant enrichment of differentially expressed genes in the pathway related to 'cellular amino acid biosynthesis and metabolism'. Functional assessment showed that the knockout of two arginine biosynthesis genes (EV232 and EV289) resulted in defects in conidia germination, mycelial growth, lunate conidia formation, and virulence of E. vermicola CBS115803 in Bursaphelenchus xylophilus. Remarkably, the addition of arginine to the MM improved mycelial growth, conidiation and lunate conidia formation in the mutants and notably increased conidia yield and the lunate conidia ratio in the wild‐type E. vermicola CBS115803. CONCLUSION: This investigation confirms the essential role of two arginine biosynthesis genes in lunate conidia formation in E. vermicola CBS115803. The findings also suggest that the supplementation of arginine to the culture medium can enhance the lunate conidia yield. These insights contribute significantly to the application of E. vermicola CBS115803 in managing Bursaphelenchus xylophilus infections. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

An efficient protein extraction method to ensure successful separation by two-dimensional electrophoresis (2-DE) is a critical step for any proteomics study. The objective of this study was to compare four previously published protein extraction protocols to identify a suitable protein extraction method to extract total proteins from cotton (Gossypium hirsutum L.) seedlings, a recalcitrant plant tissue. The results suggested that trichloroacetic acid/acetone precipitation combined with phenol extraction method (Method D) produced the purest sample and the most proteins spots (321), particularly basic proteins in the 2-DE image. The extraction method combining acetone precipitation and phenol (Method B) gave 216 spots in the 2-DE image. The trichloroacetic acid/acetone precipitation method (Method A) is not suitable for the cotton seedlings because only small molecular weight proteins were visualized in the 2-DE image. The phenol extraction method (Method C) showed 240 spots in the 2-DE gel but gave higher gel background. We subsequently selected and optimized Method D to extract protein from cotton seedlings. After optimization, more than 900 spots were detected on the 2-DE gel with pH 3-10 nonlinear gradient strip and 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel using Coomassie brilliant blue G-250 staining. Our results suggest that the optimized Method D is expected to have excellent applications in proteomic studies of cotton seedlings.

State-to-state differential cross sections for rotationally inelastic collisions of vibrationally excited NO with Ar have been measured in a near-copropagating crossed beam experiment at collision energies of 530 and 30 cm -1 . Stimulated emission pumping (SEP) to prepare NO in specific rovibrational levels is coupled with direct-current slice velocity map imaging to obtain a direct measurement of the differential cross sections. The use of nearly copropagating beams to achieve low NO-Ar collision energies and broad collision energy tuning capability are also demonstrated. The experimental differential cross sections (DCSs) for NO in v = 10 in specific rotational and parity states are compared with the corresponding DCSs predicted for NO in v = 0 obtained from quantum mechanical close coupling calculations to highlight the differences between the NO( v = 10)-Ar and NO( v = 0)-Ar interaction potentials.

Verticillium dahliae is a soil-borne, hemibiotrophic phytopathogenic fungus that causes wilting in crop plants. Here, we constructed a random insertional mutant library using Agrobacterium tumefaciens-mediated transformation to study the pathogenicity and regulatory mechanisms of V. dahliae. The fungal-specific transcription factor-encoding gene Vdpf was shown to be associated with vegetative growth and virulence, with the highest transcript expression occurring during conidia formation in the V991 strain. The deletion mutants (ΔVdpf) and insertion mutants (IMΔVdpf) produced fewer conidia than did the wild-type (WT) fungi, which contributed to the reduced virulence. Unlike the WT, the complemented strains and IMΔVdpf, ΔVdpf formed swollen, thick-walled and hyaline mycelium rather than melanized microsclerotia. The ΔVdpf mutants were melanin deficient, with undetectable expression of melanin biosynthesis-related genes (Brn1, Brn2 and Scd1). The melanin deficiency was related to cyclic adenosine monophosphate (cAMP) and the G-protein-coupled signalling pathways in this study. Similar to the WT and complemented strains, the ΔVdpf and IMΔVdpf mutants could also successfully penetrate into cotton and tobacco roots, but displayed reduced virulence because of lower biomass in the plant roots and significantly reduced expression of pathogenicity-related genes in V. dahliae. In conclusion, these results provide insights into the role of Vdpf in melanized microsclerotia formation, conidia production and pathogenicity., (© 2016 BSPP and John Wiley & Sons Ltd.)