The structure of the growth rings in the secondary wall of the cotton hair

PROTOPLASMA ◽  
1937 ◽  
Vol 27 (1) ◽  
pp. 229-241 ◽  
Author(s):  
Thomas Kerr
Keyword(s):  
Secondary Wall ◽  
Growth Rings ◽  
Cotton Hair

scholarly journals The existence of daily growth-rings in the cell wall of cotton hairs

1919 ◽  
Vol 90 (634) ◽  
pp. 542-555 ◽  
Keyword(s):  
Cell Wall ◽  
Previous Treatment ◽  
Growth Rings ◽  
Active Growth ◽  
Daily Growth ◽  
Number Of Layers ◽  
Cotton Hair ◽  
Physical And Chemical ◽  
Seed Hair ◽  
Precise Study

From studies of the growing cotton plant in Egypt the author was led some years ago to the conclusions that the wall of the cotton-seed hair-cell was “probably composed of concentric layers, laid down during the active growth of each successive night, and numbering about twenty-five in all . . . they would thus, at the most, be about 0∙0004 mm. in depth, so that their resolution by the microscope is highly improbable without some previous treatment.” Various methods were tried with the intention of bringing these layers into the limits of microscopic vision, but it was not until five years later that an accidental observation gave the clue to a method by which the limitations of microscope observation may be extended, and these layers made actually visible. The observations which followed, demonstrating the existence of con­centric layers in the wall of the cotton-hair as well as in the “fuzz-hairs,” would have been interesting in any case on account of their bearing on all the physical and chemical problems which this typical cellulose presents. C. F. Cross has insisted on the necessity for considering cellulose problems in terms of “the ultimate fibre," but it now seems probable that the ultimate unit components must be the single layers composing the wall of the said fibre. The bare fact of the existence of such layers would have had no particular significance if it could not have been connected with previous precise study of the growth of cotton-hairs. By counting the number of layers in material previously preserved at known dates during the course of those studies, and remembering the cardinal fact that growth is daily arrested by the sunshine effect under Egyptian conditions, we have been able clearly to show that these layers are actually the growth-rings whose existence we had ventured to postulate. Knowledge of their real existence must materially affect some of our views concerning the physical properties of such hairs.

The Effect of Varying Latewood Proportion on the Radial Distribution of Lignin Content in a Pine Stem

Holzforschung ◽  
2001 ◽  
Vol 55 (5) ◽  
pp. 455-458 ◽  
Author(s):  
W. Gindl
Keyword(s):  
Radial Distribution ◽  
Secondary Wall ◽  
Lignin Content ◽  
Middle Lamella ◽  
Individual Growth ◽  
Juvenile Growth ◽  
Growth Rings ◽  
Strong Negative Correlation ◽  
Compound Middle Lamella ◽  
The Difference

Summary The radial distribution of lignin content in a pine stem was compared to latewood proportion. With the exception of the innermost juvenile growth rings, a strong negative correlation was found. However, the cell-wall lignin content of low lignin growth rings was equal to that of high-lignin growth rings. Therefore, the difference in lignin content between individual growth rings was solely due to varying ratios of high-lignin compound middle lamella to low-lignin secondary wall in thin- and thick-walled tracheids.

PERTUMBUHAN LINGKARAN POHON JATI PADA DUA SISTEM KULTUR BERBEDA DI JAWA TIMUR

2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon
Keyword(s):  
Tree Ring ◽  
Tectona Grandis ◽  
Annual Growth ◽  
Natural Growth ◽  
Growth Rings ◽  
Climate Effect ◽  
Tropical Regions ◽  
Annual Growth Rings ◽  
Chronological Sequence ◽  
Plantation Teak

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>

Molecular mechanism of AtGA3OX1 and AtGA3OX2 genes affecting secondary wall thickening in stems in Arabidopsis

2013 ◽  
Vol 35 (5) ◽  
pp. 655-665 ◽  
Author(s):  
Zeng-Guang WANG ◽  
Guo-Hua CHAI ◽  
Zhi-Yao WANG ◽  
Xian-Feng TANG ◽  
Chang-Jiang SUN ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Secondary Wall ◽  
Wall Thickening ◽  
Secondary Wall Thickening

scholarly journals MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Lignin Biosynthesis ◽  
Cell Wall Formation ◽  
Long Distance ◽  
Secondary Cell Wall Formation ◽  
Myb Transcription Factors ◽  
Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

scholarly journals Phenotypic effects of changes in the FTVTxK region of an Arabidopsis secondary wall cellulose synthase compared with results from analogous mutations in other isoforms

Plant Direct ◽  
2021 ◽  
Vol 5 (8) ◽  
Author(s):  
Jason N. Burris ◽  
Mohamadamin Makarem ◽  
Erin Slabaugh ◽  
Arielle Chaves ◽  
Ethan T. Pierce ◽  
...  
Keyword(s):  
Secondary Wall ◽  
Cellulose Synthase

Mechanical Properties of Secondary Wall and Compound Corner Middle Lamella near the Phenol-Formaldehyde (PF) Adhesive Bond Line Measured by Nanoindentation

2011 ◽  
Vol 236-238 ◽  
pp. 1746-1751 ◽  
Author(s):  
Kun Liang ◽  
Guan Ben Du ◽  
Omid Hosseinaei ◽  
Si Qun Wang ◽  
Hui Wang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Secondary Wall ◽  
Phenol Formaldehyde ◽  
Middle Lamella ◽  
Adhesive Bond ◽  
Cellular Level ◽  
Bond Line ◽  
Line Region ◽  
Penetration Behavior

To find out the penetration of PF into the wood cell wall and its effects onthe mechanical properties in the cellular level, the elastic modulus and hardness of secondary wall (S2layer) and compound corner middle lamella (CCML) near PF bond line region were determined by nanoindentation. Compare to the reference cell walls (unaffected by PF), PF penetration into the wood tissues showed improved elastic modulus and hardness. And the mechanical properties decreased slowly with the increasing the distance from the bond line, which are attributed to the effects of PF penetration into S2layer and CCML. The reduced elastic modulus variations were from18.8 to 14.4 GPa for S2layer, and from10.1 to 7.65 GPa for CCML. The hardness was from 0.67 to 0.52 GPa for S2layer, and from 0.65 to 0.52 GPa for CCML. In each test viewpoint place, the average hardness of CCML was almost as high as that of S2layer, but the reduced elastic modulus was about 50% less than that of S2layer. But the increase ratio of mechanical properties was close. All the results showed PF penetrates into the CCML. The penetration behavior and penetration depth from bond line were similar in both S2layer and CCML.

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