Fig. 4

Decrease in X. fastidiosa transmission to grape plants by paratransgenic GWSSs. P. agglomerans were painted on grape stems after mixing with guar gum. PA(WT) - wild type P. agglomerans; PA(HlyA) - P. agglomerans expressing HlyA secretion signal only; PA(Melittin) - P. agglomerans expressing melittin conjugated to HlyA; PA(SLM) - P. agglomerans expressing SLM conjugated to HlyA. The GWSSs were allowed to acquire P. agglomerans from P. agglomerans-painted plants for 48 h before an acquisition access period of 48 h on X. fastidiosa-infected grape plants. Subsequently the GWSSs were collected and two GWSSs were then confined per naive grape plant. After 24 h of inoculation access, the insects were removed and the plants were kept in a greenhouse for 30 weeks before testing them for presence of X. fastidiosa using rt-PCR. GWSSs that acquired P. agglomerans expressing HlyA secretion signal, melittin conjugated to HlyA secretion signal and SLM conjugated to HlyA secretion signal did not transmit X. fastidiosa. These are pooled results from two independent experiments