Plant growth-promoting endophytes (PGPE) are microorganisms which reside in plant tissues and are beneficial to the host in plant growth promotion and pathogen resistance. They are the eco-friendly and sustainable alternative to chemical fertilizers and pesticides. This study aimed to analyze the plant growth-promoting properties of the five endophytic fungal strains from the medicinal plant Aegle marmelos Corr. and evaluate their effects on Oryza sativa plants. Firstly, endophytes were isolated from the different parts of A. marmelos and identified by ITS sequencing. Phosphate solubilization ability was checked in Pikovskaya's agar medium, IAA secretion was measured by the Salkowski colourimetric method, and ACC deaminase activity was checked by Penrose's method. Four endophytic fungal strains with promising PGP activities were inoculated into rice seeds to check their growth promotion in rice. The strain Purpureocillium lilacinum (AMR2) enhanced the seed vigour of rice seeds and demonstrated excellent root colonization ability. Periconia byssoides (AML2) and Medicopsis romeroi (AMS3) were the most effective plant growth-promoting agents, leading to both crop yield improvement and enhanced plant morphological growth due to their great ability to solubilize inorganic phosphate, ACC deaminase activity and production of IAA and Gibberellin A3 (GA3). These endophytic strains could serve as microbial inoculants to enhance crop production, offering an eco-friendly alternative.

• Klíčová slova
• Periconia sp., ACC deaminase, Enzyme production, Gibberellin A3, IAA, Plant growth-promoting endophytes,
• Publikační typ
• časopisecké články MeSH

Endophytic microbes are plant-associated microorganisms that reside in the interior tissue of plants without causing damage to the host plant. Endophytic microbes can boost the availability of nutrient for plant by using a variety of mechanisms such as fixing nitrogen, solubilizing phosphorus, potassium, and zinc, and producing siderophores, ammonia, hydrogen cyanide, and phytohormones that help plant for growth and protection against various abiotic and biotic stresses. The microbial endophytes have attained the mechanism of producing various hydrolytic enzymes such as cellulase, pectinase, xylanase, amylase, gelatinase, and bioactive compounds for plant growth promotion and protection. The efficient plant growth promoting endophytic microbes could be used as an alternative of chemical fertilizers for agro-environmental sustainability. Endophytic microbes belong to different phyla including Euryarchaeota, Ascomycota, Basidiomycota, Mucoromycota, Firmicutes, Proteobacteria, and Actinobacteria. The most pre-dominant group of bacteria belongs to Proteobacteria including α-, β-, γ-, and δ-Proteobacteria. The least diversity of the endophytic microbes have been revealed from Bacteroidetes, Deinococcus-Thermus, and Acidobacteria. Among reported genera, Achromobacter, Burkholderia, Bacillus, Enterobacter, Herbaspirillum, Pseudomonas, Pantoea, Rhizobium, and Streptomyces were dominant in most host plants. The present review deals with plant endophytic diversity, mechanisms of plant growth promotion, protection, and their role for agro-environmental sustainability. In the future, application of endophytic microbes have potential role in enhancement of crop productivity and maintaining the soil health in sustainable manner.

• Klíčová slova
• Abiotic stress, Agricultural sustainability, Endophytes, Plant growth promotion,
• MeSH
• Ascomycota * MeSH
• Bacillus * MeSH
• Bacteria genetika   MeSH
• Basidiomycota * MeSH
• endofyty MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Endophytes are primarily endosymbiotic bacteria and fungi that colonize the interior tissues of their host plant. They enhance the host plant's growth and attenuate adverse effects of biological stress. Endophytic species of many indigenous plants are an untapped resource of plant growth-promoting microorganisms that can mitigate abiotic stress effects. Thus, this study aimed to isolate endophytes from the roots and leaves of the medicinal plant Endostemon obtusifolius to evaluate their in vitro growth-promoting capacities and drought tolerance and to characterize the most promising species. Twenty-six endophytes (fourteen bacteria and twelve fungi) were isolated and cultured from the roots and leaves of E. obtusifolius. All 26 endophytes produced flavonoids, and 14 strains produced phenolic compounds. Of the 11 strains that displayed good free radical scavenging capability (low IC50) in the 1-1-diphenyl-1-picryhydrazyl radical scavenging assay, only three strains could not survive the highest drought stress treatment (40% polyethylene glycol). These 11 strains were all positive for ammonia and siderophore production and only one strain failed to produce hydrogen cyanide and solubilize phosphate. Seven isolates showed aminocyclopropane-1-carboxylate deaminase activity and differentially synthesized indole-3-acetic acid. Using molecular tools, two promising symbiotic, drought stress tolerant, and plant growth-enhancing endophytic species (EORB-2 and EOLF-5) were identified as Paenibacillus polymyxa and Fusarium oxysporum. The results of this study demonstrate that P. polymyxa and F. oxysporum should be further investigated for their drought stress mitigation and plant growth enhancement effects as they have the potential to be developed for use in sustainable agricultural practices.

• Klíčová slova
• Lamiaceae, abiotic stress, medicinal plant, microbes, secondary metabolite,
• Publikační typ
• časopisecké články MeSH