Constitutive activation of defence‐related genes in GRAIN INCOMPLETE FILLING 1‐overexpressing (GIF1‐OE) plants. The transcript levels of the rice defence‐related genes, PATHOGENESIS‐RELATED 1a (PR1a), PR1b, PR3, PR10, WRKY45 and NONEXPRESSOR OF PATHOGENESIS‐RELATED 1 (NPR1), were assayed by quantitative real‐time polymerase chain reaction (qRT‐PCR) in gif1, GIF‐OE and wild‐type (WT) controls (gif1‐WT for gif1 and GIF1‐OE‐WT for the overexpression lines). The data are given as means ± standard error (SE) (n = 3). Significant differences in comparison with the WT control: *P ≤ 0.01; **P ≤ 0.001.