Promotion of the growth and yield of Zea mays by synthetic microbial communities from Jala maize

Abstract

Plant growth-promoting bacteria (PGPB) are a source of nutrient supply, stimulate plant growth, and even act in the biocontrol of phytopathogens. However, these phenotypic traits have rarely been explored in culturable bacteria from native maize landraces. In this study, synthetic microbial communities (SynCom) were assembled with a set of PGPB isolated from the Jala maize landrace, some of them with additional abilities for the biocontrol of phytopathogenic fungi and the stimulation of plant-induced systemic resistance (ISR). Three SynCom were designed considering the phenotypic traits of bacterial strains, including Achromobacter xylosoxidans Z2K8, Burkholderia sp. Z1AL11, Klebsiella variicola R3J3HD7, Kosakonia pseudosacchari Z2WD1, Pantoea ananatis E2HD8, Pantoea sp. E2AD2, Phytobacter diazotrophicus Z2WL1, Pseudomonas protegens E1BL2, and P. protegens E2HL9. Plant growth promotion in gnotobiotic and greenhouse seedlings assays was performed with Conejo landrace; meanwhile, open field tests were carried out on hybrid CPL9105W maize. In all experimental models, a significant promotion of plant growth was observed. In gnotobiotic assays, the roots and shoot length of the maize seedlings increased 4.2 and 3.0 times, respectively, compared to the untreated control. Similarly, the sizes and weights of the roots and shoots of the plants increased significantly in the greenhouse assays. In the open field assay performed with hybrid CPL9105W maize, the yield increased from 11 tons/ha for the control to 16 tons/ha inoculated with SynCom 3. In addition, the incidence of rust fungal infections decreased significantly from 12.5% in the control to 8% in the treatment with SynCom 3. All SynCom designs promoted the growth of maize in all assays. However, SynCom 3 formulated with A. xylosoxidans Z2K8, Burkholderia sp. Z1AL11, K. variicola R3J3HD7, P. ananatis E2HD8, P. diazotrophicus Z2WL1, and P. protegens E1BL2 displayed the best results for promoting plant growth, their yield, and the inhibition of fungal rust. This study demonstrated the biotechnological eco-friendly plant growth-promoting potential of SynCom assemblies with culturable bacteria from native maize landraces for more sustainable and economic agriculture.

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

“…Additionally, the study of microbial interactions and their impact on community functions are generally neglected. Instead, it is assumed that mixing 'biocompatible' PGPB strains (i.e., strains lacking antagonistic interactions in the spot-onlawn method), or strains presenting complementary functions will ultimately result in additive or synergistic traits (27)(28)(29)(30)(31)(32)(33)(34)(35)(36). However, community functions cannot be predicted as the sum of its parts (84) and, moreover, negative interactions are common in community assembly and stability (66,85).…”

“…However, scaling to field applications is still a limiting step (21)(22)(23)(24) probably due to the deficient incorporation of microbial ecology approaches in the development of multistrain products (25,26). In the formulation of microbial consortia, the typical approach involves mixing 'biocompatible' strains, which entails selecting microbes based on complementary functions identified through the study of strains in isolation, and including only those that do not demonstrate antagonism when paired together (27)(28)(29)(30)(31)(32)(33)(34)(35)(36).…”

Beneficial endophytic fungi improve the yield and quality of Salvia miltiorrhiza by performing different ecological functions

“…In addition, endophytic fungi can induce systemic resistance (SR) in host plants by triggering the transmission of signaling molecules such as jasmonic acid (JA) and ethylene (ET) ( De Lamo & Takken, 2020 ). SR induced by endophytic fungi was significant in enhancing plant resistance to environmental stress and pathogen invasion, as well as promoting plant growth and yield ( De la Vega-Camarillo et al, 2023 ). The endophytic fungus Piriformospora indica induces plant stress tolerance by enhancing the activity of antioxidant enzymes and the expression levels of defense- and stress-related genes( Khalid, Rahman & Huang, 2019 ).…”

Conserved patterns of sequence diversification provide insight into the evolution of two-component systems in Enterobacteriaceae

“…2b, c). Little is known about the natural ecology of these lineages, however they can be isolated from various environmental niches such as soil or water, and strains amongst these genera have been identified as plant-associated or as plant pathogens [29,[63][64][65][66][67][68][69]. The overall trend, therefore, was that TCS were more divergent than expected when comparing species adapted to animal hosts to those adapted to environmental niches/plant hosts, but less divergent than expected when comparing within those groups; the TCS of the ecologically flexible Klebsiella lineage was divergent from both groups.…”