TRNT1 and infection: These results suggested that the above-high parent expression pattern of CCA1 at 21 hpi might be responsible for significant heterosis for defense in FCS hybrids, and CCA1 tends to activate defense responses before dawn of the first infection day (21 hpi) more strongly in FCS hybrids than in their parents; this time precisely precedes the peak of expression of SA biosynthetic genes at 24 hpi in the FCS hybrids10.