Abstract
Plant species differ in response to high available manganese (Mn), but the mechanisms of sensitivity and tolerance are poorly understood. In solution culture, greater than or equal to 30 µm Mn decreased the growth of soybean (Glycine max), but white lupin (Lupinus albus), narrow-leafed lupin (Lupin angustifolius), and sunflower (Helianthus annuus) grew well at 100 µm Mn. Differences in species' tolerance to high Mn could not be explained simply by differences in root, stem, or leaf Mn status, being 8.6, 17.1, 6.8, and 9.5 mmol kg(-1) leaf fresh mass at 100 µm Mn. Furthermore, x-ray absorption near edge structure analyses identified the predominance of Mn(II), bound mostly to malate or citrate, in roots and stems of all four species. Rather, differences in tolerance were due to variations in Mn distribution and speciation within leaves. In Mn-sensitive soybean, in situ analysis of fresh leaves using x-ray fluorescence microscopy combined with x-ray absorption near edge structure showed high Mn in the veins, and manganite [Mn(III)] accumulated in necrotic lesions apparently through low Mn sequestration in vacuoles or other vesicles. In the two lupin species, most Mn accumulated in vacuoles as either soluble Mn(II) malate or citrate. In sunflower, Mn was sequestered as manganite at the base of nonglandular trichomes. Hence, tolerance to high Mn was ascribed to effective sinks for Mn in leaves, as Mn(II) within vacuoles or through oxidation of Mn(II) to Mn(III) in trichomes. These two mechanisms prevented Mn accumulation in the cytoplasm and apoplast, thereby ensuring tolerance to high Mn in the root environment.
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Claims 10
Claim · model-written summary
At 30 µm or more manganese, soybean growth decreased.
- Taxon
- soybean
Glycine maxe0 - Treatment
- greater than or equal to 30 µm Mne0
- Outcome
- growthe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“greater than or equal to 30 µm Mn decreased the growth of soybean (Glycine max)”
Claim · model-written summary
White lupin grew well at 100 µm manganese.
Verbatim
e0“white lupin (Lupinus albus), narrow-leafed lupin (Lupin angustifolius), and sunflower (Helianthus annuus) grew well at 100 µm Mn”
Claim · model-written summary
Narrow-leafed lupin grew well at 100 µm manganese.
Verbatim
e0“narrow-leafed lupin (Lupin angustifolius), and sunflower (Helianthus annuus) grew well at 100 µm Mn”
Claim · model-written summary
Sunflower grew well at 100 µm manganese.
- Taxon
- sunflower
Helianthus annuuse0 - Outcome
- grew welle0
- Qualifier
- 100 µm Mne0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sunflower (Helianthus annuus) grew well at 100 µm Mn”
Claim · model-written summary
Root, stem and leaf manganese status alone did not explain species tolerance differences.
Verbatim
e0“Differences in species' tolerance to high Mn could not be explained simply by differences in root, stem, or leaf Mn status”
Claim · model-written summary
Mn(II), mostly bound to malate or citrate, predominated in roots and stems of all four species.
Verbatim
e0“predominance of Mn(II), bound mostly to malate or citrate, in roots and stems of all four species”
Claim · model-written summary
Soybean leaves accumulated high manganese in veins and manganite in necrotic lesions.
- Taxon
- soybeanGlycine maxe0
- Outcome
- high Mn in the veins, and manganite [Mn(III)] accumulated in necrotic lesionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In Mn-sensitive soybean, in situ analysis of fresh leaves using x-ray fluorescence microscopy combined with x-ray absorption near edge structure showed high Mn in the veins, and manganite [Mn(III)] accumulated in necrotic lesions”
Claim · model-written summary
The two lupin species accumulated most manganese in vacuoles as soluble Mn(II) malate or citrate.
Verbatim
e0“In the two lupin species, most Mn accumulated in vacuoles as either soluble Mn(II) malate or citrate”
Claim · model-written summary
Sunflower sequestered manganese as manganite at the base of nonglandular trichomes.
- Taxon
- sunflowerHelianthus annuuse0
- Organ / stage
- nonglandular trichomese0
- Outcome
- Mn was sequestered as manganitee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In sunflower, Mn was sequestered as manganite at the base of nonglandular trichomes”
Claim · model-written summary
The authors ascribed high manganese tolerance to effective leaf sinks that prevent cytoplasm and apoplast accumulation.
Not reportedTaxon
Verbatim
e0“tolerance to high Mn was ascribed to effective sinks for Mn in leaves, as Mn(II) within vacuoles or through oxidation of Mn(II) to Mn(III) in trichomes. These two mechanisms prevented Mn accumulation in the cytoplasm and apoplast”
The same questions in other papers
manganese atom · growth · Glycine max (soybean)Results differ
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- positive
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See all 31 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.