Complete genome sequencing and the mitochondrial genome analysis of Tylenchulus semipenetrans, an important Tylenchulidae nematode causing citrus slow decline disease

Le résumé fourni par la source

Abstract Tylenchulus semipenetrans is considered the most devastating nematode pest of citrus, causing significant damage to all citrus-producing regions worldwide. The present study, the T. semipenetrans from the rhizosphere of Citrus grandis was sequenced using Illumina and Oxford Nanopore technologies, yielding a high-contiguity 68.9 Mb assembly (N50 = 670.6 kb). Gene prediction based on RNA-seq data led to the annotation of 11,068 protein-coding genes. This assembly represents the first long-read assembled genome for the Criconematoidea superfamily. A total of 291 genes were identified as horizontal gene transfer (HGT) candidates, with 192 from bacteria, 66 from archaea, 20 from other eukaryota, and 13 from varidnaviria. We identified two GH5_2 cellulase paralogs that were clustered with insects but distinct from those of other nematodes. The GH18 chitinase gene g7408.t1 was placed within an early-diverging Tylenchida clade, supporting its vertical inheritance from a common Tylenchida ancestor. Spanning 23,157 bp, the T. semipenetrans mitochondrial genome is among the largest known in the phylum Nematoda. This genome contains 56% non-coding regions, limiting protein-coding sequences to 44% yet encoding 12 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), and 2 ribosomal RNAs (rRNAs). The genome highlights evolutionary adaptations driven by horizontally acquired CAZymes, such as GH5-family cellulases, that facilitate parasitic success by degrading the plant cell wall.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.