Effects of extended growth periods on subcellular distribution, chemical forms, and the translocation of cadmium inImpatiens walleriana

Abstract

Impatiens walleriana plants accumulate sufficiently high concentrations of cadmium (Cd) for this species to be considered a potential Cd hyperaccumulator. Rooted cuttings were grown hydroponically for 25 and 50 days in solutions spiked with various Cd concentrations. The subcellular distribution and chemical forms of Cd in different organs were analyzed, and its upward translocation was also assessed. The plants accumulated large amounts of Cd; the Cd concentration in the roots and shoots reached 120-1900 and 60-1600 mg/kg, respectively. Regardless of the growth period, the Cd accumulated in the roots was primarily compartmentalized in the soluble fraction or ethanol and deionized water extractable chemical forms with high migration abilities. Translocation to the shoots was followed by an association of Cd mainly in the cell wall or with pectate and protein. The roots' Cd showed a high migration capacity for predicting the shoots' Cd concentrations. Different exposure periods significantly affected the subcellular distribution of Cd in the stems, and thus the upward translocation.

Comparative Chloroplast Genome Analysis of Impatiens Species (Balsaminaceae) in the Karst Area of China: Insights Into Genome Evolution and Phylogenomic Implications.

“…. Additionally, high levels of metals such as copper, zinc, chromium, and nickel can be accumulated by the Impatiens species based on the previous research [ 21 ].…”

Cadmium Hyperaccumulation and Translocation in Impatiens Glandulifera: From Foe to Friend?

“…The highest Cd concentration was observed in the roots of plants in Cd-90 (14,361 ± 6164 mg/kg, Table 2). The roots of I. glandulifera were able to hyperaccumulate impressive concentrations of Cd (822 to 14,361 mg/kg Cd) far exceeding those observed in I. walleriana (29.5 to 1900 mg/kg Cd; [20,31]) and other phytoaccumulator species, e.g., Tagetes patula (273.77 mg/kg) and Eichhornia crassipes (6103 mg/kg); see Sun et al [65] and Zhu et al [66], respectively. There was no difference observed in accumulation by nodes and internodes, and therefore these results were averaged and presented as stems.…”

“…Most plants compartmentalize Cd in the cell wall or the vacuole of the roots as a method of tolerating the toxicity of the heavy metal, i.e., to sequester it from the root cytoplasm, preventing Sustainability 2019, 11, 5018 6 of 17 translocation to the shoots and thereby protecting photosynthesis apparatus [17,57]. In I. glandulifera, the Cd was compartmentalized primarily in the cell wall and was translocated and stored in all plant parts-similar to I. walleriana and other phytoaccumulator plants [28,31]. translocation to the shoots and thereby protecting photosynthesis apparatus [17,57].…”

“…translocation to the shoots and thereby protecting photosynthesis apparatus [17,57]. In I. glandulifera, the Cd was compartmentalized primarily in the cell wall and was translocated and stored in all plant parts-similar to I. walleriana and other phytoaccumulator plants [28,31].…”

“…However, some ornamental species have been identified as promising sources of new potential phytoremediators [24,25]. For example, recent research has highlighted I. walleriana, the common busy lizzie, as a promising hyperaccumulator of Cd, capable of tolerating up to 120 mg/kg of Cd [20,31,32]. Impatiens glandulifera was originally introduced as an ornamental species and is now a widespread invasive across Europe and North America.…”