Glycinebetaine-Induced Alteration in Gaseous Exchange Capacity and Osmoprotective Phenomena in Safflower (Carthamus tinctorius L.) under Water Deficit Conditions

Abstract

Several inorganic and organic compounds including glycine betaine (GB) are presently being used as an exogenous application to enhance tolerance in plants to different environmental stresses. The current study assessed to what extent exogenously applied GB could improve the gaseous exchange capacity and primary and secondary metabolites in two accessions (16178 and 16180) of safflower (Carthamus tinctorius L.) plants under drought stress. Three-week-old plants of both safflower accessions were subjected to well-watered (control) or water-deficit conditions (60% field capacity (FC)). Three levels of GB (control, 50 mM and 100 mM) were sprayed to the foliage of the control and stressed plants after one month of drought application. After two weeks of foliar application of GB, gas exchange characteristics and other biochemical parameters were determined. The results showed that water deficiency markedly suppressed plant biomass, chlorophyll contents, photosynthesis rate (A), water use efficiency (A/E), stomatal conductance (gs) and relative water contents (RWC) of both accessions of safflower, while it enhanced the levels of osmolytes (GB and proline), hydrogen peroxide (H2O2) and total phenolics. Foliar application of GB was effective in enhancing the plant biomass, chlorophyll contents, gs, sub-stomatal CO2 concentration (Ci), Ci/Ca ratio, osmolytes, H2O2, ascorbic acid (AsA), total phenolics and RWC in safflower plants under water shortage. Thus, exogenous application of GB could be used as an effective strategy to improve plant growth, photosynthetic attributes and secondary metabolites in safflower plants under water deficit conditions.

Influence of Glycine Betaine (Natural and Synthetic) on Growth, Metabolism and Yield Production of Drought-Stressed Maize (Zea mays L.) Plants

“…In the current experiment, both maize cultivars showed increased levels of leaf proline and glycine betaine under drought stress conditions. Generally, a high accumulation of GB or proline is considered as a prospective indicator of stress tolerance [9,10,53]. Moreover, in this experiment, foliar application of SBE and GB increased the concentration of these osmolytes in both maize cultivars under drought conditions.…”

“…[7,8]. Glycine betaine is a quaternary ammonium compound endogenously synthesized in chloroplasts in response to abiotic stressors, such as drought and salinity [9,10]. Glycine betaine not only acts as an osmoregulator but also stabilizes the structures and activities of enzymes and protein complexes and maintains the integrity of membranes against the damaging effects of drought [11].…”

Foliar application of ascorbic acid enhances salinity stress tolerance in barley (Hordeum vulgare L.) through modulation of morpho-physio-biochemical attributes, ions uptake, osmo-protectants and stress response genes expression

“…Stress is characterized as any external limitation of abiotic (salinity, heat, water, etc.) or biotic (herbivore) that limits the photosynthesis rate and decreases the ability of a plant to convert energy into biomass ( Alam et al, 2020 , Ali et al, 2020 , Nazar et al, 2020 , Zaheer et al, 2020b ). World agriculture faces many problems, such as the production of 70% more food for the increasing population, and crop productivity does not increase in tandem with food demand ( Ali et al, 2021 , Parihar et al, 2015 , Saleem et al, 2020b , Zaheer et al, 2020d ).…”

Effect of Foliar Application of Various Nitrogen Forms on Starch Accumulation and Grain Filling of Wheat (Triticum aestivum L.) Under Drought Stress

“…N and water interact in significant ways that affect wheat growth. Water deficit impedes plant N uptake, causing a nitrogen deficiency which aggravates the damage caused by drought stress (Gonzalez-Dugo et al, 2010;Alam et al, 2020;Nazar et al, 2020). Efficacious N fertilizer management attenuates the effects of drought on wheat by maintaining normal crop physiology and scavenging reactive oxygen species (ROS) formed in response to drought stress (Agami et al, 2018;Guo et al, 2019).…”