Endophytic Bacteria from Elephant Grass Improves Growth and Salt Tolerance of Hybrid Pennisetum

Elephant grass (Pennisetum purpureum) and hybrid pennisetum (Pennisetum americanum × P. purpureum) are perennial C4 grasses that are potential biomass feedstock. However, increasing biomass yield and stress tolerance of these two crops is required for them to be considered for commercial production. Previously, bacterial endophytes have been used as biofertilizers to improve biomass yield of energy crops.

Jiangsu University's Xia Li and Xiaoyan Geng isolated endophytic bacteria strains from the roots of elephant grass and classified them into four genera: Sphingomonas, Pantoea, Bacillus, and Enterobacter. The team then selected four representative strains from each genus and tested their effects on plant growth and salt stress tolerance of hybrid pennisetum.

Inoculation with the mixture the four bacteria induced a significant plant growth increase of hybrid pennisetum under normal and salt stress conditions. All strains were found to solubilize phosphate, fix nitrogen, produce indole acetic acid and ammonia. The availability of phosphate, nitrogen, IAA and ammonia resulted in the improved growth and salt tolerance of hybrid pennisetum.

These results suggest that inoculants can be exploited to establish large-scale feedstock production for hybrid pennisetum even on saline marginal lands.