Piriformospora indica employs host’s putrescine for growth promotion in plants

Abstract

Growth promotion by endosymbiont Piriformospora indica has been observed in various plants; however, specific functional metabolites involved in P. indica mediated growth promotion are unknown. A GC-MS based untargeted metabolite analysis was used to identify Solanum lycopersicum metabolites altered during P. indica mediated growth promotion. Metabolomic analysis showed primary metabolites altered and specifically putrescine to be maximally induced in roots during the interaction. P. indica induced putrescine biosynthetic gene SlADC1 in S. lycopersicum and acts via arginine decarboxylase (ADC) mediated pathway. P. indica did not promote growth in Sladc-VIGS (virus induced gene silencing of SlADC gene) lines of S. lycopersicum and when the ADC enzyme was inhibited with an inhibitor, DL-α-(Difluoromethyl) arginine. In Arabidopsis adc knock-out mutants, P. indica do not promote growth and this response was rescued upon exogenous application of putrescine. Putrescine promoted growth by elevation of auxin (indole-3-acetic acid) and gibberellin (GA4, GA7) levels in S. lycopersicum. Putrescine is also important for P. indica hyphal growth indicating that it is co-adapted by both host and microbe. Hence, we conclude that putrescine is an essential metabolite and its biosynthesis in plants is crucial for P. indica mediated growth promotion and fungal growth.

Endophytic Klebsiella aerogenes HGG15 stimulates mulberry growth in hydro-fluctuation belt and the potential mechanisms as revealed by microbiome and metabolomics

“…Metabolites in plant roots usually exert a variety of functions, such as facilitating primary metabolism and root growth, rhizosphere communication, and plant defense (Doell et al, 2021). Mutualistic interactions of plant with endophyte can facilitate plant growth promotion through the accumulation of beneficial plant metabolites (Kundu et al, 2021), as in the case of fungus Piriformospora indica that colonize in Chinese cabbage, which stimulated plant synthesis of metabolites involved in the tryptophan and phenylalanine metabolism as well as γ-aminobutyrate (Hua et al, 2017). Furthermore, Bacillus amyloliquefaciens enhanced maize growth by improving nutrient uptake and influencing plant primary metabolism, especially glucose, fructose, alanine and γ-aminobutyric acid metabolism (Vinci et al, 2018).…”

Plant microbiomes as contributors to agricultural terroir

“…In an example of a growth promoting endophyte influencing the plant metabolome, inoculation of grape roots with endophytic Paraburkholderia phytofirmans PsJN, triggered the overexpression of all phenylpropanoid and flavonoid pathway genes, as well as increasing the relative amounts of 32 and 17 different compounds in roots and leaves respectively (Miotto-Vilanova et al, 2019). The root endophyte Piriformospora indica stimulates tomato and Arabidopsis growth by upregulating host production of putrescine; a polyamine so named for smelling like rotting meat (Kundu et al, 2022). Inoculating pot grown apple trees with a blend of 9 different plant growth-promoting bacterial endophytes isolated from wild black cottonwood and willow trees, increased root growth, delayed leaf senescence, and significantly increased fruit mass and soluble sugar content (Rho et al, 2020).…”

A thermoresponsive CA-PNIPAM-based electrospun nanofibrous membrane for oil/water separation

“…However, these technologies have major shortcomings, mainly low selectivity, high operating cost, long separation time together with the energy requirement, and generation of secondary pollution. [5][6][7] Among them, the membrane separation process aided the advantage for the oil/water separation process due to low synthesis cost and simple and high efficiency environmentally benign process, urgently needed for oil/water separation and recovery. 8,9 Recently, several exciting or intelligent materials have been discovered to synthesize polymeric membranes highlighting their flexibility and tunable reactive surfaces for achieving controllable and switchable surface hydrophilicity and hydrophobicity for oil/water separation applications.…”