3.9 BPH infestation altered the expression and
m6A modification of cellulose synthesis-related genes
Both Bph30 and Bph40genes were significantly upregulated upon BPH infestation (Figure 4a).
Therefore, the potential correlation between m6A
levels and the expression of rice genes involved in cellulose and
hemicellulose synthesis was analyzed. Among thirteen candidate cellulose
synthesis genes which containing m6A modification
sites, eight genes were upregulated
in BPH-infested plants (Figure 4b).
Moreover, there were total 39 up- and 23
down-directed differential
m6A modification positions among the 13 cellulose
synthesis genes, 5 of which showed up-trending m6A
methylation, that is, the number of
up-directed m6A sites was higher than that of
down-directed m6A sites
(Supporting Information: Table S11,
S13). m6A modifications and the relative expression of
genes in cellulose synthesis were positively correlated, suggesting that
m6A modification is largely involved in the synthesis
of cellulose. Additionally, four of the six hemicellulose synthesis
(CSLF4 , CSLHl ,IRX10 , and IRX14 ) were upregulated, while IRX9 was
downregulated in BPH-infested plants (Figure 4c). However, only four
genes (CSLF2 , CSLHl , IRX9 , and IRX14 ) were
detected with m6A positions (Supporting Information:
Table S11, S14) and no fixed regular patterns were found.
Moreover, the contents of cellulose and hemicellulose were measured. BPH
infestation induced cellulose and hemicellulose
accumulation in rice. This degree
of induction was more pronounced for cellulose accumulation than for
hemicellulose (Figure 4d,e), which were validated the RT-qPCR and
transcriptome data. Taken together, BPH infestation activated the
expression and m6A modification of cellulose but not
apparent in hemicellulose synthesis-related genes, and was more
prominent in cellulose synthesis.