Interactive Effects of Lanthanum and Calcium on Cadmium Accumulation in Wheat with Special Reference to TaNramp5 Expression Regulated by Calmodulin

Abstract

Lanthanum (La), calcium (Ca), and cadmium (Cd) have similar physical and chemical properties because of their similar ionic radius. Although the interactions between La, Ca, and Cd have been frequently reported in plants, few studies have investigated the interactive effects of La and Ca on the growth and Cd accumulation in plants. Therefore, we investigated the interactive effects of La and Ca on the growth and Cd accumulation in wheat under Cd exposure by a hydroponic experiment. The results indicated that wheat growth was significantly affected by La−Cd and La−Ca interactions. The accumulation of Cd in wheat was significantly affected by La−Ca and La−Cd interactions and La−Ca−Cd interplay. Correlation analysis indicated that Ca deficiency stimulated La to promote wheat growth and mitigate Cd toxicity. Simultaneously, a low Ca supply stimulated La to decrease Cd accumulation in wheat and induce TaNramp5 expression. In addition, Cd accumulation in wheat was significantly affected by the W7−La interaction and W7−La−Ca interplay. All of the results suggested that La, Ca, and Cd probably share the same binding sites in calmodulin (TaCaM) and La could affect Cd accumulation in wheat by interacting with TaCaM and then downregulating the expression of TaNramp5.

Nanomaterial Size and Surface Modification Mediate Disease Resistance Activation in Cucumber (Cucumis sativus)

“…42 Yang et al (2021) reported that La could share the same binding site in calmodulin with Ca and thereby reduce the accumulation of Cd in wheat. 16 Moreover, calmodulin and calmodulin-like proteins are important regulators against plant disease and after binding Ca 2+ ; they regulate the expression of pathogenesis-related genes and improve plant resistance. 43 Hence, we hypothesized that La 2 O 3 NMs could interact with calmodulin, thereby regulating plant defense.…”

“…15 More importantly, La has a higher binding affinity to protein than Ca due to its stronger electropositivity. 16 Therefore, we hypothesized that La 2 O 3 NMs could sustainably supplement La ions in plants to activate CaM functions, subsequently increasing SA content and promoting SAR. Additionally, research has demonstrated that the bioavailability of NMs is closely related to its surface properties (e.g., hydrophobicity and surface charge) and size.…”

“…The ionic radius of La ion (1.06 Å) is similar to that of Ca (0.99 Å), which can make La ion also bind with CaM to activate its functions . More importantly, La has a higher binding affinity to protein than Ca due to its stronger electropositivity . Therefore, we hypothesized that La 2 O 3 NMs could sustainably supplement La ions in plants to activate CaM functions, subsequently increasing SA content and promoting SAR.…”

Lanthanum-based nanomaterials suppress bacterial wilt in tomato: importance of particle morphology and dissolution profiles

“…Rare earth elements have been used as agricultural amendments to promote plant growth and suppress disease occurrence. [10][11][12] After amendment with rare earth elements, more than 100 crops exhibited 5-15% increases in production over untreated controls. 13 Lanthanum (La), one of the most commonly used rare earth elements, has similar properties to calcium (Ca) due to its similar ionic radius (1.06 Å) to that of Ca (0.99 Å).…”

“…[15][16][17] Importantly, La has a stronger binding affinity to CAM than Ca due to its greater electropositivity. 11 Wang et al (2016) reported that foliar application with low concentration (30 μM) La ions could enhance the CAM levels and function in Arabidopsis leaves, while higher concentrations (80 μM) inhibited the activity due to disrupted protein structure. 18 NMs have been shown to sustainably deliver nutrients or active compounds for plant growth or to effectively convey resistance due to their high bioavailability and tunable-release profiles.…”