First de novo Transcriptome Assembly of Litylenchus crenatae, the Causal Agent of Beech Leaf Disease

The lack of genomic resources needed to support molecular and functional experiments can be a significant bottleneck for the understanding of how plant-pathogenic nematodes infect their hosts and progress through their life cycles. Fourteen years after the initial discovery of beech leaf disease (BLD), no studies have been published that explore gene expression in either the pathogen or its host during disease development. BLD is caused by the plant-parasitic nematode Litylenchus crenatae (LC), an invasive, migratory foliar nematode responsible for the widespread decline and mortality of American beech ( Fagus grandifolia ) throughout the eastern United States. Here, we present the first de novo transcriptome assembly for LC, generated from seven RNA-seq libraries comprising 264.9 million paired-end reads. The resulting 286.00 Mb assembly contained 211,841 transcripts representing 106,173 Trinity genes and 128,837 protein-coding ORFs, of which 87.3% were supported by Swiss-Prot sequence similarity and/or Pfam protein domains. Overall, 96.76% of processed read pairs mapped back to the assembly, while BUSCO assessment against the Nematoda lineage recovered 79.9% complete BUSCOs. This publicly available transcriptome (TSA Project Accession: GLPY01000000), together with its annotation (DOI: 10.5061/dryad.x69p8d01c), provides a foundational genomic resource to support future investigations into the molecular basis of parasitism, host-pathogen interactions, and other aspects of the biology of this emerging forest pathogen and other similar systems.