As　an　important　mangrove　species,　Kandelia　obovata　plays　an　irreplaceable　role　in　the　coastal　ecosystem.　However,　due　to　a　lack　of　genetic　technology,　there　is　limited　research　on　its　functional　genes.　As　such,　establishing　an　efficient　and　rapid　functional　verification　system　is　particularly　important.　In　this　study,tobacco　rattle　virus　(TRV)　and　the　phytoene　desaturase　gene　KoPDS　were　used　as　the　vector　and　target　gene,　respectively,　to　establish　a　virus-induced　gene　silencing　system　(VIGS)　in　K.　obovata.　Besides,　the　system　was　also　used　to　verify　the　role　of　a　Chlorophyll　a/b　binding　protein　(Cab)　gene　KoCAB　in　leaf　carbon　sequestration　of　K.　obovata.RNA-Seq　and　qRT-PCR　showed　that　the　highest　gene-silencing　efficiency　could　reach　90%　after　10　days　of　inoculation　and　maintain　above　80%　after　15　days,　which　was　achieved　with　resuspension　buffer　at　pH　5.8　and　Agrobacterium　culture　at　OD600　of　0.4-0.6.　Taken　together,　the　TRV-mediated　VIGS　system　established　herein　is　the　first　genetic　analysis　tool　for　mangroves,　which　may　greatly　impel　functional　genomics　studies　in　mangrove　plants.