Mechanism for Down-Regulating Gene Expression in Tropical Monocots

ABSTRACT Virus-induced gene silencing (VIGS) has been shown to be effective for transient knockdown of gene expres-sion in plants to analyze the effects of specific genes in development and stress-related responses. VIGS is well established for studies ofmodel systems and cropswithin the Solanaceae, Brassicaceae, Leguminaceae, and Poaceae, but only recently has been applied to plants residing outside these families. Here, we have demonstrated that barley stripe mosaic virus (BSMV) can infect two species within the Zingiberaceae, and that BSMV–VIGS can be applied to specifically down-regulate phytoene desaturase in the culinary ginger Zingiber officinale. These results suggest that extension of BSMV–VIGS to monocots other than cereals has the potential for directed genetic analyses of many important temperate and tropical crop species. Key words: Barley stripe mosaic virus; virus-induced gene silencing; VIGS; Zingiber officinale; Monocot