Abstract
Anatomical investigation showed that callus cultures of Populus nigra L. cv. ‘Italica’ contain lignified parenchyma cells and that large amounts of lignin are localized in intercellular spaces. A tissue-culture strain on a medium containing IAA also showed differentiation of tracheids with lignified walls. In the plant, lignin was found in the primary xylem, secondary xylem, phloem, and periderm. The lignin from primary xylem gave a negative Mäule reaction. Lignins from callus cultures and from the plant were compared and quantitatively determined. A method was developed to calculate the lignin content of tissues from the lignothioglycolic acid yield and the absorption at 250 nm in the so-called difference spectrum. Oxidation with nitrobenzene yielded syringaldehyde (S) and vanillin (V) from tissue cultures, young and old secondary xylem, phloem, and periderm; primary xylem gave vanillin but no syringaldehyde. For tissue cultures, young secondary xylem, phloem, and periderm, the S/V ratio is lower than for differentiated wood. For 2,4-D cultures the S/V ratio was lower than for a strain cultured on an IAA medium. The aldehyde yield, calculated as a percentage of the lignin, is appreciably higher for secondary xylem (42%) than for phloem, periderm, and tissue cultures (12–18%). Xylem lignin contains 9–10% esterified p-hydroxybenzoic acid. Less of this acid is found in the lignin of young secondary xylem (5.2%) and the tissue cultures (2.8–6.7%). Phloem lignin has a still lower p-hydroxybenzoic acid content (0.6%). Lignin rich in p-hydroxybenzoic acid is characterized by a very high absorption in the difference spectrum at 296 nm, strong absorption in the infrared spectrum at 1265 cm-1, and an extra absorption band at 766 cm-1. After hydrolyzation, this lignin lacks the 766 band in the IR spectrum and shows much less absorption at 1265 cm–1. Alkali lignin was prepared by a 16-hour extraction with 0.5 N NaOH at 70 °C. Complete extraction of the lignin from the tissue samples was rarely obtained. Lignin preparations deriving from the various tissue regions of the plant and from the callus cultures show mutual differences. The lignin of the callus cultures shows the greatest resemblance to the lignin of young secondary xylem but is much more resistant to oxidation. In this respect it shows a closer relationship to the lignin from the phloem and primary xylem of the tree. The terms “angiosperm lignin” and “hardwood lignin” applied to a lignin with a high syringaldehyde content are very misleading, because not all the lignified tissues of dicotyledonous trees contain this type of lignin.
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Claims 19
Claim · model-written summary
Populus callus contains lignified parenchyma cells and intercellular lignin.
- Taxon
- Populus nigra L.
Populus nigrae0 - Material
- ‘Italica’e0
- Organ / stage
- callus culturese0
- Outcome
- lignified parenchyma cellse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“callus cultures of Populus nigra L. cv. ‘Italica’ contain lignified parenchyma cells and that large amounts of lignin are localized in intercellular spaces”
Claim · model-written summary
An IAA medium strain differentiated tracheids with lignified walls.
Verbatim
e0“A tissue-culture strain on a medium containing IAA also showed differentiation of tracheids with lignified walls”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Lignin occurs in primary and secondary xylem, phloem and periderm.
Verbatim
e0“In the plant, lignin was found in the primary xylem, secondary xylem, phloem, and periderm”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Primary xylem lignin gave a negative Mäule reaction.
Verbatim
e0“The lignin from primary xylem gave a negative Mäule reaction”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Lignin content can be calculated from lignothioglycolic acid yield and 250 nm absorption.
Verbatim
e0“A method was developed to calculate the lignin content of tissues from the lignothioglycolic acid yield and the absorption at 250 nm in the so-called difference spectrum”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Nitrobenzene oxidation yielded syringaldehyde and vanillin in the listed nonprimary tissues.
Verbatim
e0“Oxidation with nitrobenzene yielded syringaldehyde (S) and vanillin (V) from tissue cultures, young and old secondary xylem, phloem, and periderm”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Primary xylem yielded vanillin but no syringaldehyde.
Verbatim
e0“primary xylem gave vanillin but no syringaldehyde”
t0“POPULUS NIGRA L.”
Claim · model-written summary
S/V ratio was lower in tissue cultures, young secondary xylem, phloem and periderm than differentiated wood.
Verbatim
e0“For tissue cultures, young secondary xylem, phloem, and periderm, the S/V ratio is lower than for differentiated wood”
t0“POPULUS NIGRA L.”
Claim · model-written summary
2,4-D cultures had a lower S/V ratio than an IAA-medium strain.
Verbatim
e0“For 2,4-D cultures the S/V ratio was lower than for a strain cultured on an IAA medium”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Secondary xylem aldehyde yield was 42%.
Verbatim
e0“aldehyde yield, calculated as a percentage of the lignin, is appreciably higher for secondary xylem (42%) than for phloem, periderm, and tissue cultures (12–18%)”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Phloem, periderm and tissue cultures had 12–18% aldehyde yield.
Verbatim
e0“phloem, periderm, and tissue cultures (12–18%)”
t0“POPULUS NIGRA L.”
e1“The aldehyde yield, calculated as a percentage of the lignin, is appreciably higher for secondary xylem (42%) than for phloem, periderm, and tissue cultures (12–18%)”
Claim · model-written summary
Xylem lignin contains 9–10% esterified p-hydroxybenzoic acid.
Verbatim
e0“Xylem lignin contains 9–10% esterified p-hydroxybenzoic acid”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Young secondary xylem lignin has 5.2% p-hydroxybenzoic acid.
Verbatim
e0“young secondary xylem (5.2%)”
t0“POPULUS NIGRA L.”
e1“Less of this acid is found in the lignin of young secondary xylem”
Claim · model-written summary
Tissue culture lignin has 2.8–6.7% p-hydroxybenzoic acid.
Verbatim
e0“the tissue cultures (2.8–6.7%)”
t0“POPULUS NIGRA L.”
e1“Less of this acid is found in the lignin of young secondary xylem”
Claim · model-written summary
Phloem lignin has 0.6% p-hydroxybenzoic acid.
Verbatim
e0“Phloem lignin has a still lower p-hydroxybenzoic acid content (0.6%)”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Lignin rich in p-hydroxybenzoic acid showed distinct absorbance bands.
Verbatim
e0“Lignin rich in p-hydroxybenzoic acid is characterized by a very high absorption in the difference spectrum at 296 nm, strong absorption in the infrared spectrum at 1265 cm-1, and an extra absorption band at 766 cm-1”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Hydrolysis removed the 766 band and reduced 1265 cm–1 absorption.
Not reportedComparator
Verbatim
e0“After hydrolyzation, this lignin lacks the 766 band in the IR spectrum and shows much less absorption at 1265 cm–1”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Complete lignin extraction from tissue samples was rarely achieved.
Verbatim
e0“Complete extraction of the lignin from the tissue samples was rarely obtained”
t0“POPULUS NIGRA L.”
Claim · model-written summary
Callus lignin most resembled young secondary xylem but was more resistant to oxidation.
Verbatim
e0“The lignin of the callus cultures shows the greatest resemblance to the lignin of young secondary xylem but is much more resistant to oxidation”
t0“POPULUS NIGRA L.”