Polyols as biomarkers and bioindicators for 21st century plant breeding

Abstract

Abstract. Characterising changes in the plant metabolome is central to understanding adaptive responses to environmental change. New and improved quantitative and qualitative technologies have enabled the characterisation of plant metabolism at unprecedented scales and precision. New frontiers have therefore emerged for improving our understanding of the adaptability of plant metabolic networks. However, despite these advances, outcomes for 'in field' plant management remain largely based on subsets of plant metabolism due to broader scale network complexity. The synthesis and occurrence of polyols offer considerable promise as bioindicators of plant health and biomarkers for use as selective traits for plant improvement. Polyols are polyohydroxy compounds that may be either open chain (acyclic) alditols or cyclic compounds (cyclohexan-hexols), usually termed cyclitols or inositols. Here we highlight the functions of polyols in stress acclimation or amelioration and as sinks for carbon and indicate their potential for the development of integrated measures of plant function using new technologies in 21st century plant breeding.

Diversity of the composition and content of soluble carbohydrates in seeds of the genus Vicia (Leguminosae)

“…The primitive ancestors accumulated RFOs in seeds, whereas the ability to synthesize galactosides of myo-inositol methyl derivatives (D-ononitol, D-pinitol, D-bornesitol) developed later, as a result of the synthesis of different cyclitols in vegetative tissues, presumably due to the pressure of unfavorable environmental conditions. The accumulation of methyl derivatives of myo-inositol can be an element of mechanisms ensuring tolerance to abiotic stresses such as: salinity, drought and cold (Merchant and Richter, 2011). Developing embryos are unable to convert myo-inositol into methyl derivatives, or even to epimerize of D-ononitol to D-pinitol (Obendorf and Górecki 2012).…”

The Relationship Between Bound Water and Carbohydrate Reserves in Association with Cellular Integrity in Fragaria vesca Stored Under Different Conditions

“…Consequently, variations in the levels of sucrose, glucose, and fructose are thought to be linked to the changes in FOS. Sugar alcohols, or polyols, are also closely associated with hexose metabolism, and they act as compatible solutes in response to salt and drought stress, playing multiple roles in plant protection (Williamson et al 2002;Merchant and Richter 2011). However, the mechanism by which polyhydroxyalcohols could protect fruits under changing environmental conditions is less well understood.…”

The occurrence and accumulation of d-pinitol in fenugreek (Trigonella foenum graecum L.)

“…Pinitol can be translocated through both phloem (Kordan et al 2011) and xylem (Krishnan et al 2011), and diurnal changes in its concentration were detected (Krishnan et al 2011). Thus, it is most likely that an important role of d-pinitol is to act as a carbon sink, enabling the allocation of carbon from carbohydrates and supporting primary metabolism during changes in resource availability at changing environmental conditions (Merchant and Richter 2011). Indeed, the differences in the concentrations of d-pinitol between organs of juvenile fenugreek plants (higher in stems, leaves and the apical bud − 20-26 mg g −1 DW, than in cotyledons − 12.29 mg g −1 DW, Online Resources, Table 2) seem to provide confirmation of the upward transport of d-pinitol from sources (leaves, cotyledons) to growing tissues (apical bud), as it was suggested by Kawai et al (1985).…”

“…Moreover, cyclitols can regulate the antioxidant systems activity Zhang et al 2017) and facilitate ion transport under salinity stress (Sengupta et al 2008). However, under stress conditions affecting osmotic potential in cells, the short-term turnover of cyclitols is very low (Smith and Philips 1982;Merchant and Richter 2011). In leaves and stems of different plant species, both herbaceous (Bieleski 1994;Streeter et al 2001) and woody plants (Adams et al 2010;Warren et al 2011;Dauwe et al 2012;Lintunen et al 2016), the concentration of d-pinitol (or other species-specific cyclitols) is as high or higher than that of sucrose, the main photoassimilate transported from sources to sink tissues.…”