Use of lanthanides to alleviate the effects of metal ion-deficiency in Desmodesmus quadricauda (Sphaeropleales, Chlorophyta)

Abstract

Lanthanides are biologically non-essential elements with wide applications in technology and industry. Their concentration as environmental contaminants is, therefore, increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants, even though their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements. We tested the effect of low concentrations of lanthanides on the common freshwater microalga Desmodesmus quadricauda, grown under conditions of metal ion-deficiency (lower calcium or manganese concentrations). Our goal was to test if lanthanides can replace essential metals in their functions. Physiological stress was recorded by studying growth and photosynthetic activity using a pulse amplitude modulation (PAM) fluorimeter. We found that nutrient stress reduced parameters of growth and photosynthesis, such as maximal quantum yield, relative electron transport rate, photon capturing efficiency and light saturation irradiance. After adding low concentrations of five lanthanides, we confirmed that they can produce a stimulatory effect on microalgae, depending on the nutrient (metal) deprivation. In the case of a calcium deficit, the addition of lanthanides partly alleviated the adverse effects, probably by a partial substitution of the element. In contrast, with manganese deprivation (and at even lower concentrations), lanthanides enhanced the deleterious effect on cellular growth and photosynthetic competence. These results show that lanthanides can replace essential elements, but their effects on microalgae depend on stress and the nutritional state of the microalgae, raising the possibility of environmental impacts at even low concentrations.

In Vivo Shaping of Inorganic Functional Devices using Microalgae

“…Very recently, a vacuole‐like compartment was identified in E. huxleyi , where Ca 2+ and Sr 2+ are stored before being dispatched to build the coccoliths in the coccolith vesicle 14,42. If the terbium ions used in our study also take this pathway into the coccolith is speculative, but seems likely since the Tb 3+ are regarded as substitutes for Ca 2+ in the metabolism of microalgae as previously reported 16,30. Further investigations on the underlying biomineralization process in E. huxleyi for generating calcite coccoliths with incorporated Tb 3+ are needed.…”

“…Even though lanthanides are nonessential elements, they are taken up by microalgae and can have stimulatory effects 30. They can replace Ca 2+ in the cells and it was suggested that Ca 2+ transporters play a role in the internalization of these elements into microalgae 30,31. Different lanthanides accumulate in different parts of the cells 32.…”

Lanthanum Affects Bell Pepper Seedling Quality Depending on the Genotype and Time of Exposure by Differentially Modifying Plant Height, Stem Diameter and Concentrations of Chlorophylls, Sugars, Amino Acids, and Proteins

“…According to Chaturvedi et al (2014), the application of 5–50 μM La in Vigna radiata, V. mungo , and maize increased the concentrations of chlorophylls a, b and total. This response is explained by the fact that La may substitute Mg 2+ during the formation of chlorophyll molecules (Hong et al, 2002; Goecke et al, 2015) and therefore more atoms for the formation of the chlorophyll molecule could be available in the growth medium. Furthermore, La may change the morphology of the external membrane of the chloroplast, which improves the structure of the organelle and leads to a higher concentration of functional nutrients such as N in the chloroplast (Hu et al, 2016b).…”

Evaluation of Rare Earths viewed from the Occupational Health

“…랫드에 34 mg/kg으로 기관내 투여한 결과에서는 산화란탄 > 산화네오디뮴 > 산화 세륨의 순으로 독성이 높게 나타났고 (Takaya et al, 2005), 마우스에 희토류를 30일간 반복 경구 투여하였 을 때에는 염화세륨 > 염화네오디뮴 > 염화란탄의 순 으로 독성이 높게 나타났다 (Cheng et al, 2014). 해조류 및 식물성장에 있어 희토류의 생체축적 및 부작용이 보고된 반면 (Carpenter et al, 2015), 몇몇 연구에서는 포유동물세포, 해조류 및 미세소기관에 서 희토류와 관련한 촉진 효과가 보고되고 있다 (Jenkins et al, 2011;Liu et al, 2012;Pol et al, 2014;Goecke et al, 2015). …”