Protection against tobacco mosaic virus in transgenic plants that express tobacco mosaic virus antisense RNA.

Abstract

Transgenic tobacco plants that express RNA sequences complementary to the tobacco mosaic virus (TMV) coat protein (CP) coding sequence with or without the tRNAlike structure at the 3' end of the TMV RNA were produced. Progeny of self-pollinated plants were challenged with TMV to determine their resistance to infection. Plants that expressed RNA sequences complementary to the CP coding region and the 3' untranslated region, including the tRNA-like sequences, were protected from infection by TMV at low levels of inocu- (6) and the expression of the insertion element ISJO (7). In these examples the antisense RNA presumably anneals with its corresponding mRNA and prevents translation (7,8).It has been shown that replication ofthe RNA coliphage SP can be inhibited by antisense RNA by expressing various antisense viral sequences in the host (9, 10). The antisense RNA for the maturase gene was the most effective molecule in these replication inhibition assays, and antisense RNA complementary to sequences at the 3' end of the viral RNA had a lesser effect. Since the latter region contained only the 3' one-third ofthe replicase gene and the 3' noncoding region, the result indicates that antisense RNA may be effective at blocking replication in RNA viruses independent of its ability to block translation. (Fig. 1B)

6 Manipulation of Plant Gene Expression by Antisense RNA

“…However, in each case the antisense RNA strategy was found to be considerably less effective than expression of the coat protein. A similar result was obtained for tobacco plants expressing tobacco mosaic virus antisense RNA (Powell et al, 1989). In this case, plants expressing antisense RNA to the coat protein coding region and the 3' untranslated region were protected from infection by TMV at low levels of inoculum.…”

Interference with brome mosaic virus replication by targeting the minus strand promoter

“…Experiments by Powell et al (1989) using antisense RNAs to inhibit the replication of tobacco mosaic virus revealed that these RNAs were effective only when sequences complementary to the 3' tRNA-like structure were present. Rezaian et al (1988) obtained only weak protection against cucumber mosaic virus (CMV) using sequences complementary to the 5' translational start site of CMV RNA-1, and antisense transcripts directed against the 3' non-coding region that did not include the terminal 135 bases were ineffective.…”

“…Ahlquist et al (1984) made use of a hybrid arrest strategy to localize the site of BMV replicase recognition by use of cDNAs complementary to the 3' ends of viral RNAs. Recently there have been a number of attempts to apply the antisense strategy both to gene expression in plants (Delauney et at., 1988;teller et al, 1991) and to interfere with virus replication (Rezaian et al, 1988;Cuozzo et al, 1988;Hemenway et al, 1988;Powell et al, 1989).…”

Characterization of Antisense Transformed Plants Deficient in the Tobacco Anionic Peroxidase

“…In most cases the predicted phenotype is observed in transformed plants harboring the antisense gene, e.g. virus resistance (Powell et al, 1989), delayed senescence (Picton et al, 1993), and altered partitioning of sugar (Kuipers et al, 1995). However, there are some notable exceptions in which the antisense RNA suppression of gene expression produces unexpected results.…”