Morphological Responses and Gene Expression of Grain Amaranth (Amaranthus spp.) Growing under Cd

Abstract

Phytoremediation efficiency depends on the ability of plants to accumulate, translocate and resist high levels of metals without symptoms of toxicity. This study was conducted to evaluate the potential of grain amaranth for remediation of soils contaminated with Cd. Three grain amaranth varieties, “Pribina” (A. cruentus), “Zobor” (A. hypochondriacus x A. hybridus) and Plainsman (A. hypochondriacus x A. hybridus) were tested under different level of Cd (0, 5, 10 and 15 mg/L) in a hydroponic experimental treatment. All could be classified as Cd excluders or Cd-hypertolerant varieties able to grow and accumulate significant amounts of Cd from the hydroponic solution, preferentially in the roots. Under the highest level of Cd exposure, qRT-PCR expression analysis of five stress-related genes was examined in above- and below-ground biomass. The results show that the Cd concentration significantly increased the mRNA level of chitinase 5 (Chit 5) in amaranth roots as the primary site of metal stress. The involvement of phytochelatin synthase (PCS1) in Cd detoxification is suggested. Based on our findings, we can conclude that variety “Pribina” is the most Cd-tolerant among three tested and can be expected to be used in the phytomanagement of Cd loaded soils as an effective phytostabiliser.

The Effect of “Production during Remediation” of Plants in Cd-Contaminated Soil

“…Study showed that the extraction rate of green amaranth in the soil with a Cd concentration of 5 mg•kg −1 was 0.35%, higher than that of some Cd hyperaccumulators. The aboveground bioaccumulation and transport factors were 1.10 and 1.29 respectively, but its biomass was only 19.23 g•pot −1 , resulting in small Cd accumulation of 0.11 mg•pot −1 [28]. He et al (2018) investigated the variety-dependent ability of tolerance and accumulation of Cd in green amaranth [29].…”

Identification and gene expression analysis of cytosine-5 DNA methyltransferase and demethylase genes in Amaranthus cruentus L. under heavy metal stress

“…Amaranth ( Amaranthus cruentus L.) variety “Pribina”, previously bred and registered in Slovakia, was used for the analysis. Amaranth plants were cultivated as previously described by Lancíková et al. (2020) .…”

“…RNA isolation, reverse transcription and quantitative PCR were performed as previously described ( Lancíková et al., 2020 ). In summary, total RNA was extracted according to the protocol based on TriZOL reagent ( Chomczynski and Mackey, 1995 ).…”

“…Grain amaranths, namely Amaranthus cruentus , A. hypochondriacus , and A. caudatus are highly nutritional pseudocereals characterized by the ability to tolerate environmental stress ( Coelho et al., 2018 ; Lancíková et al., 2020 ; Pulvento et al., 2022 ). There is still a little known about the molecular mechanisms responsible for such a strong stress tolerance, and even less is known about epigenetic regulation in Amaranthus .…”

Advances in “Omics” Approaches for Improving Toxic Metals/Metalloids Tolerance in Plants

“…9-, and 3.7-fold, compared with its expression in shoots in Amaranth. cruentus , A. hypochondriacus × A. hybridus , and A. hypochondriacus × A. hybridus , respectively ( Lancíková et al, 2020 ). Alfalfa plant experienced a 25- and 29-fold increase in detoxifying enzyme superoxide dismutase (SOD) transcripts in response to bulk Cu and nano Cu, respectively ( Cota-Ruiz et al, 2020 ).…”