Comparative Molecular and Metabolic Profiling of Two Contrasting Wheat Cultivars under Drought Stress

Abstract

Drought is one of the most important threats to plants and agriculture; therefore, understanding of the mechanisms of drought tolerance is crucial for breeding of new tolerant varieties. Here, we assessed the effects of a long-term water deficit stress simulated on a precision phenotyping system on some morphological criteria and metabolite traits, as well as the expression of drought associated transcriptional factors of two contrasting drought-responsive African wheat cultivars, Condor and Wadielniel. The current study showed that under drought stress Wadielniel exhibits significant higher tillering and height compared to Condor. Further, we used gas chromatography and ultra-high performance liquid chromatography mass-spectrometry to identify compounds that change between the two cultivars upon drought. Partial least square discriminant analysis (PLS-DA) revealed that 50 metabolites with a possible role in drought stress regulation were significantly changed in both cultivars under water deficit stress. These metabolites included several amino acids, most notably proline, some organic acids, and lipid classes PC 36:3 and TAG 56:9, which were significantly altered under drought stress. Here, the results discussed in the context of understanding the mechanisms involved in the drought response of wheat cultivars, as the phenotype parameters, metabolite content and expression of drought associated transcriptional factors could also be used for potential crop improvement under drought stress.

Precision phenotyping across the life cycle to validate and decipher drought-adaptive QTLs of wild emmer wheat (Triticum turgidum ssp. dicoccoides) introduced into elite wheat varieties

“…As drought in our study started at the tillering stage and lasted until maturity, all these components were affected by progressing drought stress. Similar observations were made in a recent study in spring wheat ( Fadoul et al, 2021 ).…”

Comparative metabolomics of root-tips reveals distinct metabolic pathways conferring drought tolerance in contrasting genotypes of rice

“…Proline was the most significantly altered metabolite among all common metabolites. Proline behaves as an osmolyte for osmotic adjustment and helps in stabilization of subcellular structures, prevention of oxidative burst and is the explanation for increased drought tolerance [ 73 ]. Proline was found in higher concentrations in the roots of Azucena under stress conditions than in IR64 (39% more).…”

Editorial: Identification and characterization of contrasting genotypes/cultivars to discover novel players in crop responses to abiotic/biotic stresses, volume II

“…Among the abiotic stresses that affect plants, drought is one of the main factors which reduces growth and yield, with an estimated third of the total cultivated area affected by water deficit. Therefore, we need to improve our knowledge of the molecular mechanisms underlying drought tolerance in order to develop new drought tolerant genotypes (Fadoul et al, 2021). In light of ever increasing climate change and the new agricultural challenges this brings, A ́lvarez-Maldini et al emphasized the importance of identifying and selecting anisohydric woody plants that are able to withstand cavitation better than isohydric plants.…”