Biotech Updates

Emerging Threat to Virus Resistant Transgenic Papaya

July 18, 2008

Researchers at the Transworld Institute of Technology and the National Chung Hsing University in Taiwan reported that they have isolated a strain of papaya leaf distortion mosaic virus (PLDMV) named P-TW-WF that infects transgenic papaya resistant to papaya ring spot virus (PRSV). The P-TW-WF strain believed to be a new pathotype of PLDMV causing vein-clearing, mosaic on leaves of infected papaya seedlings, and water-soaking streaks on the petioles and stems - disease symptoms that are similar to that caused by PRSV.

Taiwan's PRSV resistant papayas have been proven resistant to PRSV for several years of field trial. The PLDMV P-TW-WF strain was isolated during their fourth field trial. The researchers have now generated transgenic papaya lines resistant to PLDMV using the PLDMV coat protein (CP) and among their future endeavors include generation of PRSV-PLDMV double transgenic lines by crossing the PLDMV resistant lines with the existing PRSV-resistant transgenic lines and also by generating resistant plants using chimeric constructs comprising (full or parts of) PRSV and PLDMV P-TW-WF CP genes.

The full report published in Phytopathology journal can be accessed by subscribers at http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-98-7-0848