Contribution of seed-endophytic bacteria to drought tolerance in early developmental stages of native maize landraces from arid milpas

Harnessing Emergent Properties of Microbial Consortia: Assembly of the Xilonen SynCom

“…strains (Supplementary Table S1). These bacterial taxonomic groups have been previously found to be relevant for the fertility of native maize varieties (16–18). It is important to note that a bottom-up approach testing all combinations of size k = {2, 3, 4} from 27 strains would entail preparing and screening 20,826 co-cultures.…”

“…Our recent studies in native maize from milpa traditional agroecosystems revealed that seed-endophytic bacteria that remain on the seedling root upon germination appear to be particularly important for the fertility of these plants (16–18). In this fraction of the bacteriome, Bacilli strains are highly diverse and abundant, and are capable of colonizing the seedling root (16).…”

“…can be highly antagonistic and could mediate community assembly and biocontrol (17). Finally, Pseudomonas spp., contribute to drought tolerance in landraces from arid milpas (18). Since the functions attributed to these bacterial genera were described for axenic cultures, it is still necessary to generate more complex experimental systems that allow 1) grasping community-level functions and 2) understanding the basis of community assembly.…”

Biofilm formation and maize root-colonization of seed-endophytic Bacilli isolated from native maize landraces

“…Milpas are low-input traditional agroecosystems found in Mesoamerica where native maize landraces are cultivated in polyculture with other crops and wild plants (Gutiérrez and Gómez 2011). The soil and plant-associated microbiome from milpas is highly complex and diverse (Aguirre-Von-Wobeser et al 2018; Van Deynze et al 2018; Rebollar et al 2017); specifically, seed-endophytic bacterial communities of native maize are more abundant and diverse when compared to hybrid varieties, and include strains that could contribute to biotic and abiotic stress alleviation (Arellano-Wattenbarger et al 2023; Gastélum et al 2022). From this fraction of the bacteriome, the class Bacilli appears particularly important, since they are a dominant taxon in these communities; however, their contribution to plant fitness remains elusive.…”

“…While exploring bacterial communities associated to native maize landraces from traditional milpa agroecosystems (Gutiérrez and Gómez 2011), we found that the seed-endophytic bacteriome of these plants is dominated by strains from the class Bacilli ( i.e ., Bacillus spp. and closely related sporulating bacteria) (Arellano-Wattenbarger et al 2023; Gastélum et al 2022). These bacteria are tightly associated with the plant, and we expect that they should be able to colonize the maize rhizosphere as a first step for their internalization into the endosphere and/or for establishing symbiotic interactions with the plant.…”