Figure 6.

Effects of inhibitors and inducers of ET synthesis and perception on the induction of PGE and IR by harpin in wild-type Arabidopsis and ein mutants. A, Assays of wild-type plants in response to different treatments. Subsection a, Fresh weight of plants grown in pots. Subsection b, Numbers of aphids on leaves of plants grown in pots. Subsection c, Length of roots grown on the agar medium. B, Assays of ein2-1 plants grown on the medium. Subsection a, ET levels from roots. Subsection b, Root length. C, Assays of ein5-1 plants grown in pots. Subsection a, ET levels from leaves. Subsection b, Numbers of aphids on leaves. Solutions that contained the indicated compounds were applied separately by spraying 20-d-old potted plants or soaking seeds for 6 h before germination. Soaked seeds were placed on the agar medium for root growth. AOA and AgNO₃ (Ag) were applied together with harpin and labeled as H + AOA and H + Ag, respectively. Fresh weight of potted plants was determined at 20 dpt and is shown as weight per plant. Nymphs present on each plant were counted at 7 dpt and are shown as the number of nymphs per plant. Lengths of roots grown on medium were measured at 10 dpt. At 12 hpt, ET was quantified with fresh weight (FW) of leaves. Bars in the histograms represent sd.