<p>Using Barley stripe mosaic virus (BSMV) as a vector and the phytoene desaturase gene of <i>pennisetum purpureum</i> (<i>PpPDS</i>) as a reporter gene, we constructed a recombinant virus-induced gene silencing (VIGS) vector, pCaBS-γbLIC-<i>PpPDS</i>. We assessed the efficacy of this method at three stages of plant growth—stem nodes, young buds, and seedlings—and three modes of infiltration: rub inoculation, 30-min vacuum, and 60-min vacuum. The results showed that the effects of infection on the stem nodes and seedling tissues were not efficient. However, in young bud tissues, leaf whitening was observed under both 30- and 60-min vacuum infiltration, with 60% of the new leaves showing albinism under 60-min vacuum infiltration. This indicates that optimal infection efficiency was achieved under the conditions of a young bud stage and 60-min vacuum infiltration. In the absence of a stable genetic transformation system for elephant grass, the virus-induced gene silencing by barley stripe mosaic virus (BSMV-VIGS) system constructed in this study enables silencing and identification of candidate genes within 30 days, significantly shortening the screening time and accelerating the identification process. The accelerated gene functional validation capability of this system is expected to provide significant support for the functional verification of elephant grass gene resources and the breeding of new varieties.</p> Graphic Abstract <p></p>