Figure 1.

Silencing phytoene desaturase (PDS) in the leaves of hexaploid wheat by barley stripe mosaic virus–virus-induced gene silencing (BSMV-VIGS). The first and second leaves of wheat plants were inoculated with a control construct BSMV:00, which carries no plant gene sequence, and BSMV:PDS, which carries a 185-bp fragment of the PDS gene. The white photobleached areas result from degradation of chlorophyll when PDS expression is silenced. (A higher-magnification image of photobleaching can be seen at the bottom left image in Fig. 2.)


Figure 2.

Using barley stripe mosaic virus–virus-induced gene silencing (BSMV-VIGS) to identify genes functioning in Lr21-mediated resistance to leaf rust. All plants were infected with the indicated BSMV constructs 7 d after germination and then spray-inoculated with the leaf rust fungus Puccinia triticina 8 d after viral infection. The photographs were taken 10 d after inoculation with the leaf rust fungus. R, WGRC7 genotype expressing Lr21-mediated resistance; S, the susceptible genotype Wichita, which lacks Lr21 Left column photographs: Infection with control constructs does not alter resistance or susceptibility. Right column photographs: BSMV constructs silencing Lr21, RAR1, SGT1, and HSP90 abrogate Lr21-mediated resistance. (Scofield et al., 2005).