Calcium Application Enhances Drought Stress Tolerance in Sugar Beet and Promotes Plant Biomass and Beetroot Sucrose Concentration

Abstract

Numerous studies have demonstrated the potential of sugar beet to lose the final sugar yield under water limiting regime. Ample evidences have revealed the important role of mineral nutrition in increasing plant tolerance to abiotic stresses. Despite the vital role of calcium (Ca2+) in plant growth and development, as well as in stress responses as an intracellular messenger, its role in alleviating drought stress in sugar beet has been rarely addressed. Here, an attempt was undertaken to investigate whether, and to what extent, foliar application of Ca2+ confers drought stress tolerance in sugar beet plants exposed to drought stress. To achieve this goal, sugar beet plants, which were grown in a high throughput phenotyping platform, were sprayed with Ca2+ and submitted to drought stress. The results showed that foliar application of Ca2+ increased the level of magnesium and silicon in the leaves, promoted plant growth, height, and leaf coverage area as well as chlorophyll level. Ca2+, in turn, increased the carbohydrate levels in leaves under drought condition and regulated transcriptionally the genes involved in sucrose transport (BvSUC3 and BvTST3). Subsequently, Ca2+ enhanced the root biomass and simultaneously led to induction of root (BvSUC3 and BvTST1) sucrose transporters which eventually supported the loading of more sucrose into beetroot under drought stress. Metabolite analysis revealed that the beneficial effect of Ca2+ in tolerance to drought induced-oxidative stress is most likely mediated by higher glutathione pools, increased levels of free polyamine putrescine (Put), and lower levels of amino acid gamma-aminobutyric acid (GABA). Taken together, this work demonstrates that foliar application of Ca2+ is a promising fertilization strategy to improve mineral nutrition efficiency, sugar metabolism, redox state, and thus, drought stress tolerance.

Ameliorative Effects of Calcium Sprays on Yield and Grain Nutritional Composition of Maize (Zea mays L.) Cultivars under Drought Stress

“…The biosynthesis of ABA has improved water use efficiency and confer drought tolerance in plants [28]. Calcium foliar application improved drought tolerance in maize [29], sugar beet [30], wheat [31], and tea [32]. Fan [33] indicated that Ca concentration of 10 mM achieves the highest maize grain yield under both normal and drought conditions.…”

Responses of Moringa oleifera to alteration in soil properties induced by calcium nanoparticles (CaNPs) on mineral absorption, physiological indices and photosynthetic indicators

“…Salinity reduces plant growth, creates an imbalance in soilwater, disrupts plant cell functions and induces metabolic disorders in plants. Nanoparticles such as nitric oxide are reportedly efficient in reducing salinity, and similarly, Ca is known to regulate the salinity of soil [3,40,[58][59][60]. Correspondingly, CaNPs would be efficiently better as a soil conditioner to reduce salinity stress and provide essential minerals by maintaining K concentration.…”

Application of beet sugar byproducts improves sugar beet biofortification in saline soils and reduces sugar losses in beet sugar processing

“…This could be resulted from the high calcium content of the applied soil amendments which is antagonized with sodium ions and improves soil aggregation and hence improves the chemical and physical soil characteristics and ultimately enhances plant growth and yield (Miller &Smith 2010). Moreover, the high sucrose content resulted from the control treatment might be due to that the partitioning of photoassimilates was in favor of increasing sucrose content in the control treatment where root yield was decreased (Hosseini et al 2019, Koch et al 2019, Lemoine et al 2013, Sowiński 1999). In addition, sucrose content has been reported to be reduced in response to increasing beet root yield by the dilution effect (Shaheen et al 2017).…”