Sequence similarity between the viral cp gene and the transgene in transgenic papayas

Pesquisa Agropecuária Brasileira

Manoel Teixeira Souza Júnior²  Dennis Gonsalves¹ 

[1] ,Embrapa Recursos Genéticos e BiotecnologiaBrasília DF ,Brazil

关键词: Carica papaya;    potyvirus;    resistance;    breeding;    virus;    Carica papaya;    potyvirus;    resistência;    melhoramento;    vírus;   

DOI  :  10.1590/S0100-204X2005000500009

来源: SciELO

【 摘 要 】

The Papaya ringspot virus (PRSV) coat protein transgene present in 'Rainbow' and 'SunUp' papayas disclose high sequence similarity (>89%) to the cp gene from PRSV BR and TH. Despite this, both isolates are able to break down the resistance in 'Rainbow', while only the latter is able to do so in 'SunUp'. The objective of this work was to evaluate the degree of sequence similarity between the cp gene in the challenge isolate and the cp transgene in transgenic papayas resistant to PRSV. The production of a hybrid virus containing the genome backbone of PRSV HA up to the Apa I site in the NIb gene, and downstream from there, the sequence of PRSV TH was undertaken. This hybrid virus, PRSV HA/TH, was obtained and used to challenge 'Rainbow', 'SunUp', and an R2 population derived from line 63-1, all resistant to PRSV HA. PRSV HA/TH broke down the resistance in both papaya varieties and in the 63-1 population, demonstrating that sequence similarity is a major factor in the mechanism of resistance used by transgenic papayas expressing the cp gene. A comparative analysis of the cp gene present in line 55-1 and 63-1-derived transgenic plants and in PRSV HA, BR, and TH was also performed.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License