Publications

4535

An anaerobic, salt-tolerant, rod-shaped bacterium, strain JL216-2 T , was isolated from the shell of the hydrothermal gastropod Alviniconcha marisindica in the Tianxiu hydrothermal field on the Carlsberg Ridge, Indian Ocean. Cells of strain JL216-2 T were motile and 0.5×3–6 µm in size. Strain JL216-2 T grew at 10–32 °C (optimal 28 °C), pH 6.0–9.0 (optimal pH 7.0) and 0.5–12.0% (w/v) sodium chloride(NaCl, optimal 2.5%). Strain JL216-2 T exhibited metabolic versatility, being capable of heterotrophic growth on complex organic compounds. It also performed autotrophic growth by utilizing carbon dioxide (CO₂) fixation or sodium bicarbonate (NaHCO 3 ) as the sole carbon source, driven by hydrogen oxidation coupled with Fe(III) reduction. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain was most closely related to Helicovermis profundi S502 T (90.43% sequence similarity). The genome size of strain JL216-2 T was 4.91 Mb, with a G+C content of 39.54 mol%. Phylogenomic analysis and overall genome relatedness indices values indicated a close relatedness of strain JL216-2 T to H. profundi S502 T and Fusibacter spp. The combined genotypic and phenotypic data showed that strain JL216-2 T represents a novel genus within the order Eubacteriales . The type strain is JL216-2 T (=MCCC M30262 T =KACC 23553 T ).

First sugar beet varieties with reasonable yield stability under infection with Candidatus Arsenophonus phytopathogenicus (ARSEPH), the causal agent of the syndrome “Basses Richesses” (SBR), were discovered, but the mechanisms behind this have not been described yet. Thus, this research aimed at analyzing different morphological, physiological and quality related traits of ARSEPH infected sugar beet taproots to identify methods for SBR variety screening. In a greenhouse experiment, one susceptible and two tolerant varieties were infected with ARSEPH via the vector Pentastiridius leporinus (reed glass-winged cicada) under controlled conditions. In the susceptible variety, an infection with ARSEPH caused an average reduction in volume (~40%), length (~6%), width (~21%), fresh mass (~41%) and an increase in dry matter content (~5%). The tolerant varieties exhibited a lower effect on these parameters but showed a greater increase in alcohol insoluble residues (cellulose, hemicellulose, pectin, lignin) and marc content. The significant enhancement in flexural taproot tissue strength observed in the tolerant varieties may be linked to increased levels of structural cell components. The susceptible and one tolerant variety exhibited reduced periderm puncture resistance after infection. This first study of physiological and morphological traits provides deeper insights into host-pathogen interaction and potential variety response. To confirm the relevance and implications of the results as new parameters for screening of SBR-tolerant varieties, further analysis with additional varieties across a larger number of samples is necessary.