International Conference on Agriculture, Forest, Food Sciences and Technologies (ICAFOF 2017 Cappadocia / Turkey), Nevşehir, Turkey, 15 - 17 May 2017, pp.200
Pokeweed antiviral protein (PAP) of Phytolacca americana L. (Pokeweed) is a single-chain
ribosome-inactivating protein (RIP) characterized by its ability to depurinate plant ribosomes. Here, we isolated, cloned and expressed the ribosome inactivating protein (RIP) gene, designated as pokeweed antiviral protein type 1 (PAP-I) from the summer leaves of pokeweed collected from Black Sea region (Turkey). Our findings presented here provide direct evidence that exogenous application of PAP I cause concentration-dependent inhibition of Zucchini yellow mosaic virus (ZYMV) infection on squash plants. Squash plants were exposed to PAP I protein with and without DMSO for four consecutive days. Regular spraying of approx 30 kDa recombinant PAPI at 2 μg mL-1 concentration prevented treated plants from mechanical virus infection. PAP I showed antiviral activity in 9 plants out of 15 inoculated plants. Remarkably, simultaneous application of PAP, DMSO, and ZYMV did not prevent virus infection suggesting that PAP did not have any effect on viral RNA. In the absence of ZYMV the purified peptide was not cytotoxic for squash plants although a reduction of plant size, possibly caused by host ribosome depurination was observed.