Fig. 6.

The DNA sequence, methylation ratio, expression patterns of gene PPR in six rice germplasms. (a) The nucleotide sequence 1495–1577 bp upstream from the TSS of gene PPR in the typical heat-sensitive (Labelle, Kashihikari and OM997) and heat-tolerant (Huazhan, Qiyinzhan and Simiao) rice germplasms. (b) The methylation rates of the cytosines 1495–1577 bp upstream of gene PPR in the heat-sensitive and heat-tolerant rice germplasms under high nighttime temperature and normal temperature conditions. (c) The gene expression patterns of PPR in the typical heat-sensitive and heat-tolerant rice germplasms under high nighttime temperature and normal temperature conditions (original full length gel images are presented in Additional file 2: Figure S4–S9); the rice Actin1 (LOC_Os03g50885) gene was used as an internal control. T1, T2, and T3 indicate replicates exposed to high nighttime temperatures; CK1, CK2, and CK3 indicate control replicates kept at normal temperatures. (d) Weights of the rice grains produced by heat-sensitive and heat-tolerant germplasms exposed to either high nighttime temperatures or normal temperatures