Overexpression of a sorghum SnRK1βγ2 gene increases the biomass in Setaria viridis but not in rice

Sorghum asaC4crop has been shown tobe both drought tolerant and photosynthetically productive. Inthis study, wedemonstrated that sorghum SbSnRK1βγ2 (SbSNF4-2), the γ subunit ofthe sucrose non-fermenting 1 (SNF1)/SNF1-related protein kinase 1 (SnRK1) heterotrimeric complex, increased the plant height and biomass inSetaria viridis, aC4 relative ofsorghum, but not inrice, aC3 relative, when overexpressed driven bythe maize ubiquitin promoter. However, the overexpression did not increase the tiller number inS. viridis, although itcaused modest increases inthe tiller number inboth sorghum and rice. Inaddition, SbSnRK1βγ2 did not affect the panicle weight insorghum, but its overexpression doubled the panicle weight inS. viridis inall four evaluated transgenic lines. Overall, the overexpression ofSbSnRK1βγ2 tripled the biomass production inS. viridis, indicating SbSnRK1βγ2’s potential inany future cellulosic biofuel production and S. viridis’ utility as an alternative genetic vehicle to functionally characterise sorghum genes.