In search of biomarkers and the ideotype of barley tolerant to water scarcity

TL;DR

This study integrates phenotypic, proteomic, and metabolomic data to identify traits and potential biomarkers associated with barley's tolerance to water scarcity, aiming to inform breeding of drought-resistant varieties.

Contribution

It introduces a multi-omic approach to identify proteomic and metabolomic traits linked to drought tolerance in barley, proposing an ideotype for water scarcity resilience.

Findings

Six leaf proteins and five root proteins are linked to grain weight under drought.

Aspartic and Glutamic acids significantly influence grain weight.

Proteomic and metabolomic traits can serve as biomarkers for drought tolerance.

Abstract

In barley plants, water shortage causes many changes on the morphological, physiological and biochemical levels resulting in the reduction of grain yield. In the present study the results of various experiments on the response of the same barley recombinant inbred lines to water shortage, including phenotypic, proteomic and metabolomic traits were integrated. Obtained results suggest that by a multi-omic approach it is possible to indicate proteomic and metabolomic traits important for reaction of barley plants to reduced water availability. Analysis of regression of drought effect (DE) for grain weight per plant on DE of proteomic and metabolomic traits allowed us to suggest ideotype of barley plants tolerant to water shortage. It was shown that grain weight under drought was determined significantly by six proteins in leaves and five in roots, the function of which were connected with defence mechanisms, ion/electron transport, carbon (in leaves) and nitrogen (in roots) metabolism, and in leaves additionally by two proteins of unknown function. Out of numerous metabolites detected in roots only Aspartic and Glutamic acids and one metabolite of unknown function, were found to have significant influence on grain weight per plant. The role of these traits as biomarkers, and especially as suggested targets of ideotype breeding, has to be further studied. One of the direction to be followed is genetic co-localization of proteomic, metabolomic and phenotypic traits in the genetic and physical maps of barley genome that can describe putative functional associations between traits; this is the next step of our analysis that is in progress.