Endophytic fungus Falciphora oryzae promotes lateral root growth by producing indole derivatives after sensing plant signals

Abstract

The endophytic fungus Falciphora oryzae was initially isolated from wild rice (Oryza granulata) and colonizes many crop species and promotes plant growth. However, the molecular mechanisms underlying F. oryzae‐mediated growth promotion are still unknown. We found that F. oryzae was able to colonize Arabidopsis thaliana. The most dramatic change after F. oryzae inoculation was observed in the root architecture, as evidenced by increased lateral root growth but reduced primary root length, similar to the effect of auxin, a significant plant growth hormone. The expression of genes responsible for auxin biosynthesis, transport, and signalling was regulated in Arabidopsis roots after F. oryzae cocultivation. Indole derivatives were detected at significantly higher levels in liquid media after cocultivation compared with separate cultivation of Arabidopsis and F. oryzae. Consistently, the expression of indole biosynthetic genes was highly upregulated in F. oryzae upon treatment with Arabidopsis exudates. Global analysis of Arabidopsis gene expression at the early stage after F. oryzae cocultivation suggested that signals were exchanged to initiate Arabidopsis–F. oryzae interactions. All these results suggest that signalling molecules from Arabidopsis roots are perceived by F. oryzae and induce the biosynthesis of indole derivatives in F. oryzae, consequently stimulating Arabidopsis lateral root growth.

Endophyte roles in nutrient acquisition, root system architecture development and oxidative stress tolerance

“…that modulation in RSA was accompanied by regulation of the hormonal (indole acetic acid, abscisic acid, gibberellic acid) balance in roots (Liu and Wei 2019). Sun et al (2019) demonstrated the role of the endophytic fungus Falciphora oryzae in RSA development (enhanced lateral root formation) and suggested that endophytes up regulate the genes responsible for auxin synthesis and signaling.…”

Insights Into the Mechanism of Rhizosphere Microorganisms Effecting on Quality Formation of Authentic Angelica Sinensis Under Different Soil Microenvironments

“…The small moleculars secreted by roots such as amino acids, organic acids, sugars and secondary metabolites can specifically promote the growth of some soil microorganisms, causing the migration of soil microbial communities [47]. For instance, Falciphora oryzae colonized Arabidopsis roots by sensing signalling molecules from its roots, and then promoted the lateral root growth of Arabidopsis through biosynthesis of indole derivatives [48]. We speculated that rhizosphere microbes can also directly or indirectly envolved in and influence the growth and metabolism process of hosts.…”

Comparative Proteomic Analysis of Pleurotus ostreatus Reveals Great Metabolic Differences in the Cap and Stipe Development and the Potential Role of Ca2+ in the Primordium Differentiation

“…These results suggested that the exogenous application of CaCl 2 and IAA in the early developmental stage of fruiting body can affect the primordium differentiation and stipe development, especially the effect of CaCl 2 on inhibiting the stipe development. There are also reports about the effects of plant hormones on fungi development [34][35][36][37]. Considering the above analysis, we chose 1 mM of calcium chloride (CaCl2), 1 mM of sodium bicarbonate (NaHCO3), 0.01 mM of Indole-3-acetic acid (IAA), and 0.01 mM of gibberellin 3 (GA3) as the exogenous inducer to apply on the primordium of the fruiting body.…”