Fungicidal and plant growth-promoting traits of Lasiodiplodia pseudotheobromae, an endophyte from Andrographis paniculata

Abstract

IntrodutionFungal endophytes are widespread and dwell inside plant cells for at least part of their life without producing any symptoms of infection. Distinct host plants may have different fungal endophyte rates and community compositions. Despite this, the endophytic fungi connected with the host plant and their hostile behaviors, remain unknown.MethodsThe objective of the current research was to isolate and identify endophytic fungal species from the root of Andrographis paniculata. The effects of fungal isolate APR5 on the mycelial growth of phytopathogens and the production of plant-promoting traits were assessed. Results and discussionEndophytic fungal isolate APR5 showed higher inhibitory efficacy in dual and double plate assay against the tested phytopathogenic fungi. The scanning electron microscope analysis demonstrated that the phytopathogenic fungal hyphae were coiled by endophytes which makes them shrink and disintegrate. Further, an ethyl acetate crude extract effectively suppressed the mycelium growth of Rhizoctonia solani by 75 ± 0.1% in an agar well diffusion assay. The fungal isolate APR5 was identified as Lasiodiplodia pseudotheobromae using the nuclear ribosomal DNA internal transcribed spacer (ITS) region and qualitatively evaluated for their capacity to produce plant growth-promoting hormones. Gas chromatography-mass spectrometry was implemented to acquire a preliminary understanding of the secondary metabolic profile of ethyl acetate crude extract. 1-octadecene, erythritol, niacin, oleic acid, phenol, pantolactone, phenyl ethyl alcohol, p-cresol, and tbutyl hydroquinone are the metabolites analyzed in a crude extract of APR5 isolate and are reported to have antimicrobial properties.

Chemical Constituents and Biological Activities of Bruguiera Genus and Its Endophytes: A Review

“…Dahibhate et al [74] discovered that a mixture of brugierol and isobrugierol exhibited inhibitory activity against Pseudomonas aeruginosa by reducing the formation of virulence biofilms controlled by the quorum sensing system, lowering the level of virulence factors, thereby attenuating the pathogenicity of the bacterium against Bruguiera plants. Simultaneously, Zhang et al [21,75] cultured and isolated the endophytic fungus C. cladosporioides MA-299 from the leaves of B. gymnorrhiza, obtaining seven sulfur-containing 12-membered macrocyclic lactones (179)(180)(181)(182)(183)(184)(185). The potential biosynthetic pathway of these compounds is illustrated in Figure 9, with the precursor cladocladosin A featuring the bicyclo 5/9 ring system.…”

“…The compound erythritol (491) with antibacterial activity, is one of the main chemical components of the endophytic fungus Lasiodiplodia pseudotheobromae APR5 [179], and it is also produced by the endophytic fungus P. citrinum ZD6 within the stems of the Chinese medicinal plant B. gymnorrhiza [92]. The endophytic fungus L. pseudotheobromae APR5, originating from the host plant Andrographis paniculata, effectively inhibits the growth of plant pathogenic fungi [179]. Moreover, it produces the plant hormone IAA (indole-3acetic acid) and iron carrier, promoting the growth and development of the host plant and enhancing its resistance to adverse environmental conditions [179].…”

“…The endophytic fungus L. pseudotheobromae APR5, originating from the host plant Andrographis paniculata, effectively inhibits the growth of plant pathogenic fungi [179]. Moreover, it produces the plant hormone IAA (indole-3acetic acid) and iron carrier, promoting the growth and development of the host plant and enhancing its resistance to adverse environmental conditions [179]. Furthermore, the genus Penicillium has been confirmed to enhance the resistance of host plants to both biotic and abiotic stresses [180].…”

“…Some of these compounds exhibit rare structural features and demonstrate significant bioactivity. For example, in the study by Zhang et al [21], four novel 12-membered macrocyclic lactone compounds (179)(180)(181)(182) with sulfur substitution at C-2 were obtained from the endophytic fungus Cladosporium cladosporioides MA-299, isolated from the leaves of B. gymnorrhiza, and the compounds exhibited notable antimicrobial activity against aquatic bacteria (Edwardsiella tarda and Edwardsiella ictarda) and plant pathogens (Bipolaris sorokiniana, Colletotrichum glecosporioides, Fusarium oxysporum f. sp. cucumerinum, and Physalospora piricola Nose).…”