Abscisic acid, cold and salt stimulate conserved metabolic regulation in the moss Physcomitrella patens

Abstract

Salt and cold are major abiotic stresses that have adverse effects on plant growth and development. To cope with these stresses and their detrimental effects plants have evolved several metabolic, biochemical and physiological processes that are mainly triggered and mediated by the plant hormone abscisic acid (ABA). To elucidate the metabolic responses of the moss Physcomitrella patens, which serves as a model plant for abiotic stress adaptation, we performed GC-MS-based metabolic profiling of plants challenged for 5 and 28 h with either salt, cold or ABA. Our results indicate significant changes in the accumulation of several sugars including maltose, isomaltose and trehalose, amino acids including arginine, histidine, ornithine, tryptophan and tyrosine, and organic acids mainly citric acid and malonic acid. The metabolic responses provoked by ABA, cold and salt show considerable similarities. The accumulation of certain metabolites positively correlates with gene expression data whereas some metabolites do not show correlation with cognate transcript abundance. To place our results into an evolutionary context we compared the ABA- and stress-induced metabolic changes in moss to available metabolic profiles of the seed plant Arabidopsis thaliana. We detected considerable conservation between the species, indicating early evolution of stress-associated metabolic adaptations that probably occurred at the plant water-to-land transition.

ABA-Induced Vegetative Diaspore Formation in Physcomitrella patens

“…Osmoregulation seems to be a major process mediated by ABA. In P. patens genes encoding for alpha/beta amylases, sugar transporters, dehydrins, osmosensor histidine kinases and early-responsive to dehydration stress proteins are induced by ABA with a most probable function in osmoregulation (Cuming et al, 2007; Arif et al, 2018). Group I LEA proteins can be activated in angiosperms by exogenously applied ABA (Kamisugi and Cuming, 2005) and are involved in the regulatory period of dehydration at the end of seed development.…”

A Chloroplast COR413 Protein From Physcomitrella patens Is Required for Growth Regulation Under High Light and ABA Responses

“…This hypothesis is supported by the knowledge that ABA contributes to stress-induced metabolic reprogramming in P. patens, by regulating the accumulation of a large number of metabolites, including sugars, amino acids and organic acids (Arif et al, 2018).…”

“…Concerning sugar metabolites, P. patens suffers important changes in starch and soluble sugar content under a variety of abiotic stresses and in response to ABA (Bhyan et al, 2012;Takezawa et al, 2015;Gao et al, 2016;Arif et al, 2018). Sucrose is the main product of photosynthesis and a dominant regulator of plant growth.…”

From reproduction to production, stomata are the master regulators

“…The phenotypes of bryophyte mutants/overexpression lines for ABA biosynthesis and signalling components, including ABA receptors from the PYRABACTIN RESISTANCE 1 (PYR)/PYR1‐LIKE (PYL)/REGULATORY COMPONENT OF ABA RECEPTOR (RCAR) family, OST1‐like SnRK2 signalling kinases, and protein phosphatase type 2C (PP2C) proteins in mosses reveal an older role for ABA in promoting desiccation tolerance and dormancy (Komatsu et al , ; Sakata et al , ; Tougane et al , ; Komatsu et al , ; Takezawa et al , ; Eklund et al , ; Shinozawa et al , ; Jahan et al , ; Arif et al , ). This role in desiccation tolerance is also seen in lycophytes and seed plants, and involves regulation of metabolism and the biosynthesis of osmoprotectants (Cuming et al , ; Liu et al , ; Urano et al , ; Khandelwal et al , ; Arif et al , ; Jahan et al , ). In accordance with an ancient role in desiccation tolerance, ABA biosynthesis is induced by dehydration stress in all land plant groups from bryophytes to angiosperms (McAdam and Brodribb, ; e.g.…”