Opposite metabolic responses of shoots and roots to drought

Abstract

Shoots and roots are autotrophic and heterotrophic organs of plants with different physiological functions. Do they have different metabolomes? Do their metabolisms respond differently to environmental changes such as drought? We used metabolomics and elemental analyses to answer these questions. First, we show that shoots and roots have different metabolomes and nutrient and elemental stoichiometries. Second, we show that the shoot metabolome is much more variable among species and seasons than is the root metabolome. Third, we show that the metabolic response of shoots to drought contrasts with that of roots; shoots decrease their growth metabolism (lower concentrations of sugars, amino acids, nucleosides, N, P, and K), and roots increase it in a mirrored response. Shoots are metabolically deactivated during drought to reduce the consumption of water and nutrients, whereas roots are metabolically activated to enhance the uptake of water and nutrients, together buffering the effects of drought, at least at the short term.

Effects of temperature on growth and photosynthesis in the seedling stage of the sheath blight-resistant rice genotype 32R

“…Thus, shoots and roots may vie and collaborate for the functions that a plant requirement. A decrease in roots growth often precedes the decrease of shoots growth (Huang et al, 2012;Gargallo-Garriga et al, 2014). This is reason to explain why total dry weight responses of LAR was identified between rice and wheat.…”

Impacts of Global Change on Mediterranean Forests and Their Services

“…These changes in metabolomic profiles were associated with changes in the elemental composition and stoichiometry of the organisms [32,35]. Changes in the chemical composition of plants under drought and/or warming affect the palatability of plants and therefore the frequency of herbivorous attack [33,36,37]. Aerial organs and roots of the same plant can also respond oppositely to drought and warming [36,37].…”

“…Changes in the chemical composition of plants under drought and/or warming affect the palatability of plants and therefore the frequency of herbivorous attack [33,36,37]. Aerial organs and roots of the same plant can also respond oppositely to drought and warming [36,37]. The concentration of primary metabolites associated with protein synthesis and energy production, such as amino acids and sugars, and N, P and K concentrations increased in roots, whereas activities of the primary metabolic pathways associated with growth and N, P and K concentrations decreased in the aerial organs.…”

Evaluating Water Controls on Vegetation Growth in the Semi-Arid Sahel Using Field and Earth Observation Data

“…The dry season is characterized by high VPD (>2 kPa), which is linked to the reduction in evapotranspiration due to low PAW. With the reduction/closure of stomatal conductance, plants deactivate metabolic activity in the shoots to reduce consumption of water (and subsequent transpiration) while simultaneously enhancing uptake of water and nutrients by the roots to mitigate the effect of the dry season [75]. In the wetter savanna systems of the humid region (>750 mm of mean annual precipitation, MAP), it has been shown that a considerable amount of C is stored in the roots at the start of the dry season and is subsequently used by the herbaceous vegetation to re-sprout at the start of the next growing season [76].…”