Wheat growth, applied water use efficiency and flag leaf metabolome under continuous and pulsed deficit irrigation

Abstract

The intensity and frequency of precipitation events are predicted to change over the coming decades. For many areas, longer periods without rainfall are expected. We investigated the importance of irrigation frequency under water deficit conditions for growth, physiology and chemistry of wheat (Triticum aestivum). Drought-stressed plants received 40% of the water provided for control plants and were either watered every other day (continuous drought, cd) or every eight days (pulsed drought, pd). Maximum quantum yield of photosystem II (F v /f m), aboveground biomass, applied water use efficiency (WUE apl) and the flag leaf metabolome were assessed twice during development. F v /f m was not affected by irrigation. Drought-exposed plants produced less biomass, but had higher WUE apl than control plants. More metabolic features responded to the pd compared to the cd treatment and more features were increased than decreased in pool size in flag leaves. Salicylic acid glucoside was generally decreased under drought. In pd plants, two benzoxazinoid glucosides were enhanced at the first time point and concentrations of several flavonoid glycosides were modulated. This study extends our knowledge about drought effects on wheat; it highlights that the frequency of watering determines how plant growth, physiology and metabolism are affected by drought.

Phytochemical Analysis of Phenolics, Sterols, and Terpenes in Colored Wheat Grains by Liquid Chromatography with Tandem Mass Spectrometry

“…In this study, 125 biologically active compounds of a phenolic and nonphenolic nature were identified in differently pigmented wheat grains by HPLC coupled with Bruker Daltonics ion trap MS/MS (Table 1). Our annotation results are consistent with the extensive mass-spectrometric literature data on the wheat T. aestivum [27][28][29][30][31][32][33] and other plant matrices, e.g., Passiflora incarnate [34], Bituminaria [35], Phyllostachys nigra [36], Carpobrotus edulis [37], and Vaccinium macrocarpon [38]. For example, the collision-induced dissociation spectrum (in negative ion mode) of a flavone called apigenin 2 -O-sinapoyl, C-hexosyl, C-pentosyl from extracts of T. aestivum grains [line S29 BLUE (4Th-4D)] is given in Figure 7.…”

Effects of drought and mycorrhiza on wheat and aphid infestation

“…To maintain the turgor, osmolytes such as sugars and amino acids, in particular proline, are accumulated in plant cells (Singh, Kumar, Singh, Singh, & Prasad, 2015; Tatar & Gevrek, 2008). In flag leaves of wheat, various metabolites respond in distinct directions to different drought scenarios (Stallmann, Schweiger, Pons, & Müller, 2020). These changes emphasize that drought also has an impact on plant chemistry.…”

Time point- and plant part-specific changes in phloem exudate metabolites of leaves and ears of wheat in response to drought and effects on aphids

“…This herbivore proliferates particularly on the inflorescences and can cause severe yield losses by impacting grain filling and by transmitting plant viruses [ 30 ]. In a previous publication, we demonstrated that the biomass of wheat plants was lower for drought-exposed plants than for well-watered plants, indicating that drought caused some stress, whereas the applied water use efficiency was higher in drought-stressed plants [ 31 ]. Furthermore, the metabolome of wheat flag leaves differed between drought-exposed and well-watered plants, measured at two different time points [ 31 ].…”

“…In a previous publication, we demonstrated that the biomass of wheat plants was lower for drought-exposed plants than for well-watered plants, indicating that drought caused some stress, whereas the applied water use efficiency was higher in drought-stressed plants [ 31 ]. Furthermore, the metabolome of wheat flag leaves differed between drought-exposed and well-watered plants, measured at two different time points [ 31 ]. Changes in the leaf metabolome were more pronounced in plants exposed to pulsed drought stress compared to continuously drought-stressed plants, although all drought-stressed plants received the same cumulative amount of water [ 31 ].…”