At the molecular level, defence gene expression was analysed in the upper leaves of wild-type plants following the infection of lower leaves with avirulent PstAvrB, confirming the significant induction of the expression of the SA-dependent genes PR-1 and PR-5 at 48 and 72 hpi, but only weak induction of the ethylene-dependent gene ERF1 and no change in the jasmonate-dependent gene PDF1.2, in each case compared to the mock infiltration controls (Fig. 9). The gene discussed is TMEM37; the disease is infection.