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

Jana Stallmann,Caroline A A Pons,Caroline Müller,Rabea Schweiger

doi:10.1038/s41598-020-66812-1

Jana Stallmann, Caroline A A Pons + Show 2 more

Open Access

https://doi.org/10.1038/s41598-020-66812-1

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Journal: Scientific Reports	Publication Date: Jun 22, 2020
Citations: 30	License type: open-access

Affiliation: Bielefeld University

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 (Fv/Fm), aboveground biomass, applied water use efficiency (WUEapl) and the flag leaf metabolome were assessed twice during development. Fv/Fm was not affected by irrigation. Drought-exposed plants produced less biomass, but had higher WUEapl 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.

Highlights

The intensity and frequency of precipitation events are predicted to change over the coming decades
At T1, the total aboveground plant dry mass was influenced by the irrigation treatment, being significantly lower in cd compared to ctr plants and slightly higher in cd compared to pd plants (Fig. 2A, Table 2)
This study revealed that deficit irrigation affects wheat growth and WUEapl as well as thepolar metabolome of flag leaves, providing novel insights into the importance of irrigation frequency next to irrigation volume

Summary

Introduction

The intensity and frequency of precipitation events are predicted to change over the coming decades. We investigated the importance of irrigation frequency under water deficit conditions for growth, physiology and chemistry of wheat (Triticum aestivum). 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. Studies on the effects of continuous vs pulsed water availability on the phytometabolome are lacking but may reveal a deeper understanding of plant responses to climate change events important for crop breeding. Several primary metabolites accumulate under drought[9], leading to a decreased plant osmotic potential that facilitates the uptake of water from the soil[10]. Apart from changes in target primary and specialised metabolites, little is known about the magnitude and direction of overall metabolic changes in response to continuous and pulsed drought stress. For maize plants subjected to salt and drought stress, evidence was found for a relationship between physiological and metabolic changes19. (Eco-)metabolomics is an effective approach to investigate plant responses to diverse stresses[20], whereby untargeted metabolic fingerprinting can reveal shifts in large parts of the phytometabolome[21]

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