Abstract
Punch holes on peach leaves caused by Cu treatment is similar to the lesion spots on a leaf exposed to Xanthomonas campestris pv. pruni . We hypothesized that Cu treatment caused programmed cell death (PCD). First, we investigated the relation between Cu concentration and an aria of lesion on a leaf after Cu treatment. The lesion was not observed with Cu below 200 μ M but the aria of lesion spot was constant when leaf was treated with over 300 μ M Cu. Second, we tested whether Cu affected PCD or not. It is known that VPE (vacuolar processing enzyme) has caspes1 activity and plays an important roll as a determinant of PCD. We treated leaf with 500 μ M Cu with/without caspase-1 inhibitor. The lesion was almost never seen on the leaf with caspase-1 inhibitor. These results suggest Cu treatment causes hyper sensitive reaction on the peach leaves.
