Fig. 1

Expression partitioning of duplicate genes among tissues in newly synthetic rice allotetraploids. a Sampling method for different tissues and growth stages. Leaves and roots of each individual were sampled at the tillering stage, and then the sampled plants were still continuously cultivated through the booting stage. At the booting stage, the plants were sampled again, and a mature leaf, root, flag leaf and young spike were collected. L1, R1 represent expression of the mature leaf and root, respectively, at the tillering stage; L2, R2, F and S represent the expression of the mature leaf, root, flag leaf and young spike, respectively, at the booting stage. b Mean percentages of tissues showing tissue-specific silence (TSS) of alleles/homeologs for 30 genes at same growth stage (gene × tissue), in “in vitro hybrids” (2X, n = 6), F1 hybrids (2X, n = 6) and synthetic rice tetraploids (4X; NN99, n = 7 and 99NN, n = 7). Reciprocal synthetic tetraploids (99NN and NN99) were constructed from subspecies japonica (cv. Nipponbare, labelled as “N”) and indica (cv. 9311, labelled as “9”) rice. The maternal parents of 99NN and NN99 are cv. 9311 and cv. Nipponbare, respectively. The values are means of TSS (%) of six to seven biological replicates (individuals) ± standard error. * indicates a significant difference between both stages within a rice line, according to a Mann–Whitney test (P < 0.05)