The papaya (Carica papaya L.) is a popular tropical fruit crop across the world, however it is plagued by the papaya ringspot virus type P. (PRSV-P). Previous genetic study revealed a functional PRSV-P resistance marker in a mapping population of F2 plants of Vasconcellea pubescens (resistant to PRSV-P) and Vasconcellea parviflora (sensitive to PRSV-P), and demonstrated that the marker had similarity to the STK gene. The sensitivity of Carica and Vasconcellea to Papaya Ringspot Virus type P (PRSV-P) was investigated in this work using structural variations in the STK gene. Full-length cDNAs of the potential PRSV-P resistance genes CP STK and VP STK1 and VP STK2 from C. papaya and V. papaya, respectively. fast amplification of cDNA ends was used to clone pubescens (RACE). The two homologous sequences in V. pubescens are transcribed and processed differently due to a frame-shift mutation, resulting in two separate transcripts in V. pubescens, whereas they are fused into a single message in C. papaya. A peroxisomal targeting signal (PTS2) discovered in VP STK2 but not in the other transcripts might be the functional source of PRSV resistance in V. pubescens. Resistance-inducing alternative splicing may have produced the STK gene in V. pubescens. The potential resistance gene VP STK2, which was found in this study, might be a new source of PRSV-P resistance for papaya genotypes.

Author(s) Details:

M. R. Razean Haireen,
Malaysian Agricultural Research and Development Institute, Persiaran MARDI-UPM, 43400 Serdang, Selangor, Malaysia and Griffith University, Nathan Campus, 170 Kessels Road, QLD 4111, Australia.

R. A. Drew,
Griffith University, Nathan Campus, 170 Kessels Road, QLD 4111, Australia.

Please see the link here: https://stm.bookpi.org/RABS-V3/article/view/7054