The recruitment of specific rhizospheric bacteria facilitates Stevia rebaudiana salvation under nitrogen and/or water deficit stresses

Rhizosphere microbiomes contribute considerably to host‐plant fitness; however, limited information is available on their responses to abiotic stresses. Stevia (Stevia rebaudiana Bertoni) is a crop sensitive to both nitrogen and water limitations; thus, stevia was employed to explore plant and rhizobacteria responses to nitrogen and/or water stresses. Water stress specifically enhanced root biomass, whereas nitrogen deficiency caused a general plant growth inhibition and foliar steviol glycosides content surge. In contrast, the quantitative abundances of overall rhizobacteria were more sensitive to water than nitrogen deficiency. Furthermore, 128 responsive bacterial taxa within four discrete ecological categories were screened, mainly members of Proteobacteria, Bacteroidetes, and Chloroflexi phyla. Bacterial taxa motivated by nitrogen/water stress prevailingly displayed a random phylogenetic distribution, while those suppressed taxa exhibited a phylogenetically conserved ecological strategy. Moreover, the quantitative abundance of some water stress-motivated genera, such as Labilithrix and Myxobacterium, were actively correlated with stimulated root growth, while others, such as Steroidobacter and Chthonomonas, which were co-motivated by nitrogen and water stress, were positively linked to steviol glycoside synthesis. This study unveiled the adaptive assembly of rhizobacterial communities to nitrogen and/or water stresses and identified the potential core microorganisms regulating steviol glycoside synthesis and stevia tolerance.