Comparative transcriptome and DNA methylation analyses of Phytoplasma
infection Responses in Mulberry (Morus multicaulis Perr.)
Abstract
To reveal whether the response of mulberry to phytoplasma infection is
associated with DNA methylation changes, the methylome and transcriptome
patterns of mulberry leaves in response to phytoplasma infection were
explored. Though the average methylation level of infected leaves showed
no significant difference with that of healthy leaves, there were 1253
differentially methylated genes and 1168 differentially expressed genes
found in the infected leaves, and 215 genes were found simultaneously to
be differently methylated and expressed. It was found that the
expression of G-type lectin S-receptor-like serine/threonine protein
kinase gene (Mu-GsSRK) was increased, but its methylation level was
decreased in the infected leaves. Moreover, the expression of Mu-GsSRK
was increased while its methylation level was reduced in mulberry
treated with pathogen and SA. Expression of Mu-GsSRK in Arabidopsis
enhanced transgenic plant disease resistance and the expressions of some
defense genes when plants were inoculated with pathogens. In addition,
the DNA methylation dynamic patterns and the roles of the differentially
expressed and methylated genes were discussed. Our results suggested
that DNA methylation has important roles in mulberry responses to
phytoplasma infection, and the information provided there will
facilitate to elucidate the epigenetic mechanisms underlying mulberry
responses to phytoplasma infection.