Plant immunity frequently incurs growth penalties, which known as the trade-off between
immunity and growth. Heterosis, the phenotypic superiority of a hybrid over its parents, has
been demonstrated for many traits but rarely for disease resistance. Here, we report that the
central circadian oscillator, CCA1, confers heterosis for bacterial defense in hybrids without
growth vigor costs, and it even significantly enhances the growth heterosis of hybrids under
pathogen infection. The genetic perturbation of CCA1 abrogated heterosis for both defense …