期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1991
卷号:88
期号:6
页码:2331-2335
DOI:10.1073/pnas.88.6.2331
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Transgenic plants expressing the coat protein (CP) of alfalfa mosaic virus (AIMV) are resistant to infection by AIMV. A mutation was introduced into the second amino acid of the cDNA for the CP of AIMV. Three different transgenic tobacco lines expressing the mutant CP and two different transgenic tobacco lines expressing the wild-type CP at similar levels were challenged with AIMV virions and viral RNA. Whereas the lines expressing the wild-type CP were highly resistant to infection by AIMV virions and viral RNA, the lines expressing the mutant CP were susceptible to infection by both. The binding affinity of the mutant and the wild-type CPs for the 3' terminal protein binding site on AIMV RNAs was similar, as determined by electrophoretic mobility shift assay. A mixture of AIMV genomic RNAs 1-3 was infectious on the plants expressing the mutant CP but not on vector control plants or plants expressing the wild-type CP, indicating that the mutant CP can activate the AIMV genomic RNAs for infection. These results demonstrate that the second amino acid of the AIMV CP is critical for protection from AIMV but not for the initial interaction between the AIMV RNA and CP, suggesting that this initial interaction does not play a major role in CP-mediated protection.