Differential transcriptome analysis and identification of genes related to resistance to blight in three varieties of Bambusa pervariabilis x Dendrocalamopsis grandis

Background. Bambusa pervariabilis x Dendrocalamopsis grandis is a fast-growing bamboo that is widely introduced in southern China and has great economic and ecological benefits. In recent years, a blight of B. pervariabilis x D. grandis caused by Arthrinium phaeospermum has led to much branch damage and even death of entire bamboo forests. Methods. To screen for resistance genes in B. pervariabilis x D. grandis, transcriptome sequencing technology was used to compare the gene expression profiles of different varieties of B. pervariabilis x D. grandis with variable resistance and the same varieties under different treatments. The Clusters of Orthologous Groups of Proteins (COG) database; the Gene Ontology (GO) database; and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to annotate and analyse the differentially expressed genes. Results. A total of 26,157 and 11,648 differentially expressed genes were obtained in the different varieties after inoculation with A. phaeospermum and the same varieties after inoculation A. phaeospermum or sterile water, respectively. There were 23 co-upregulated DGEs and 143 co-downregulated DEGs in #3 and #8, #6 and #8, #6 and #3. There were 50 co-upregulated DGEs and 24 co-downregulated DEGs in the same varieties after inoculation A. phaeospermum or sterile water. The results showed that many genes involved in cell wall composition synthesis, redox reactions and signal transduction were significantly different after pathogen infection. Twenty-one candidate genes for blight resistance, such as pme53, cad5, pod, gdsl-ll and Myb4l, were found. The qRT-PCR results were consistent with the sequencing results, verifying their authenticity. These results provide a foundation for the further exploration of resistance genes and their functions.