Chromium tolerance mechanisms in Cosmos

Overview

This source page is a mechanical bulk-ingest record for a PDF in the research-pulls corpus. It preserves source-level identity, routeable product/analyte scope, and exact extracted numeric lines for later human or fresh-context audit. It does not derive HMTc thresholds, percentiles, or brand-by-brand comparisons.

Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

species suitable for landscaping applications, remains cient Cr phytoextractor (18, 26, 27), whereas relevant
indica (11) and Helianthus annuus (31). Integrating these tive humidity 70%, photosynthetic photon flux density
sterilized by soaking in a 2% NaClO solution for 20 min nologies, Santa Clara, CA, USA). The Cr translocation
(100, 200, 300, and 400 µM, labeled as T1–T4, respec- 10% trichloroacetic acid (TCA) and centrifuged at 4000 xg
After three weeks of normal cultivation in full-strength with 2 mL of 0.6% TBA. The mixture was then heated in a
tion was measured at 450, 532, and 600 nm. refer to Table S1.).
els, 0.5 g of fresh sample tissue was weighed and homog- A 0.25-g sample was ground with 3% TCA containing 5
dithiothreitol, and 2% polyvinyl pyrrolidone. The mixture 0.4 mL of 1 mol/L NaOH and 0.1 mL of potassium phos-
0.75 mM nitro blue tetrazolium (NBT), 0.3 mL of 0.1 mM 10 min) with 6 mL of 0.5% sulfosalicylic acid; 1 mL of the
the enzyme extract, and it was kept in darkness. One unit A 0.5-g fresh sample was collected, and to it, 5 mL of 3%
required to induce 50% inhibition of the photochemical in a boiling water bath for 10 min and then centrifuged
ate the reaction. The increase in absorbance at 470 nm A 0.2-g fresh sample was ground with 4 mL of 5% TCA
Photosynthetic pigment analysis Photosynthetic pig- mL of 0.4% phosphoric acid in ethanol, 1 mL of 5 g/L BP
tissue in 10 mL of 95% ethanol for 48 h in the dark. A added in sequence. The mixture was thoroughly mixed,
10-µL aliquot of the extract (with an equal volume of 95% and its absorbance at 525 nm (A525) was measured. The
extracted with 3 mL of 0.5% ammonium oxalate buffer at for metabolome analysis. The freeze-dried samples were
stable (Table S4). Under 100 µM Cr treatment, although
reference genes are listed in Supplementary Table S2-S3. the shoots under high Cr stress, which may be one of its
significant difference (LSD) post-hoc test was used to compared to the control, with increases of 12.8%, 89.7%,
detect pairwise differences between groups. For datas- and 33.7%, respectively (Fig. 2B–D). Starting from 200
cumulation in above-ground and below-ground parts; (C): Cr tolerance index and translocation factor. Data are presented as mean ± SD (n = 3). Different
maximum reduction in SOD activity reaching 81.9%. C. sulphureus to Cr stress. Under different Cr concentra-
response to Cr stress, while SOD and POD demonstrate atively stable without substantial variability (Fig. 2H–J).
Small-molecule metabolism is a key physiological maximum increase of 131.7%. Pro content peaked under
indicator of plant responses to abiotic stress. Under the the T1 treatment, showing a 19.5% increase compared to
respectively. Data are presented as mean ± SD (n=3). Error bars indicate standard deviation. Statistical significance was assessed using Duncan’s test, and
content in pectin reached 5 mg/g, accounting for 49.93% mediating Cr fixation.
(n=3). Error bars indicate standard deviation. Statistical significance was assessed using Duncan’s test, and different letters indicate significant differences
was higher than that in high-esterified pectin (Fig. 3Q– 0.01%, with greater than 99% and 97% of reads meeting
ity was significantly positively correlated with both the Cr of the samples ranged from 43.83% to 44.61%. Relevant
and R2 = 0.8618 (P < 0.0001), respectively. the transcriptomic data (Table S6). We excluded sam-
scriptome assembly statistics see Table S5), of which at transcripts, and the results met the quality control cri-
least 67,211 sequences (88.61%) were recorded in at least teria (Fig. S4). Furthermore, PCA demonstrated clear
along PC1, with a contribution rate of 75.06% and non- synthesis of secondary metabolites,” “Phenylpropanoid
enrichment analysis further revealed that DEGs were annotations are provided in Table S10.) closely related
to the aforementioned response pathways for cluster These DAMs primarily included organic acids (20.2%),
analysis and present the results as a heatmap in Fig. 4D. amino acids and their derivatives (18.8%), sugars and
as corresponding to antioxidant defense and second- (11.7%), phenolic acids (5.1%), and flavonoids (2.7%),
and sucrose metabolism) is summarized in Table S3. tion among the different sample groups. The OPLS-DA
1,731 metabolites were identified under Cr stress (Table significance levels for R²Y and Q² were P = 0.000615 and
in flavonoid metabolites enhance the antioxidant capac- were upregulated under Cr stress (Table S8), promot-
support CW synthesis and modification, thus enhancing pyrophosphorylase, phosphoglucomutase (Table S9), and

Methods (brief)

analytical tools in contemporary molecular biology, rinsed off with deionized water. The root samples were
investigate, through hydroponic experiments combined Fresh plant samples were collected for phenotypic mea-
the Cr accumulation potential and adaptation mecha- added, and the samples were left to digest overnight. The
Co., Ltd. (Yancheng, China). Plump seeds were surface- mass spectrometry (ICP-MS; model 7900, Agilent Tech-
els, 0.5 g of fresh sample tissue was weighed and homog- A 0.25-g sample was ground with 3% TCA containing 5
enized in 10 mL of pre-chilled 50 mmol/L phosphate mM EDTA. The sample was then centrifuged, and 2 mL
buffer (pH 7.0) containing 1 mmol/L EDTA, 1 mmol/L of the resulting supernatant was collected. Subsequently,
supernatant was collected as the crude enzyme extract. DTNB reagent, the reaction was conducted at room tem-
sisted of 0.3 mL of 130 mM methionine (MET), 0.3 mL of A 0.25-g sample was taken and centrifuged (12,000 ×g,
ethylenediaminetetraacetic acid disodium salt (EDTA- supernatant was collected, and 2 mL of 0.25 mol/L Tris-
the enzyme extract, and it was kept in darkness. One unit A 0.5-g fresh sample was collected, and to it, 5 mL of 3%
reduction of NBT. (4,000 ×g, 10 min). From the centrifuged samples, 2 mL
Catalase (CAT) activity was measured based on the of the supernatant was collected, and 2 mL of glacial ace-
the reaction solution (containing 10 mM guaiacol, 6 the fresh weight of sample). X is the mass of proline (µg)
ate the reaction. The increase in absorbance at 470 nm A 0.2-g fresh sample was ground with 4 mL of 5% TCA
(µmol·mg⁻¹·min⁻¹). ×g, 10 min), and 1 mL of the supernatant was collected.
determination utilized root CWs isolated according to sured by ICP-MS.
described by Yang et al. (40). The contents of these poly- group (i.e., untreated samples) and the Cr100 treatment

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised