scholarly journals Donald Henry Northcote. 27 December 1921—7 January 2004

2019 ◽  
Vol 67 ◽  
pp. 357-370 ◽  
Author(s):  
D. W. T. Crompton
Keyword(s):  
Cell Wall ◽  
Golgi Body ◽  
The Novel ◽  
Higher Plant ◽  
Research And Teaching ◽  
University Of Cambridge ◽  
Plant Biochemistry ◽  
Fundamental Research ◽  
Freeze Etching ◽  
Entire Career

Don Northcote became eminent in the field of plant biochemistry following his identification of the processes involved in the synthesis and deposition of polysaccharides that constitute the cell wall of plants. His researches spanned lower and higher plant species and he showed by the application of a variety of experimental techniques, including radioautography, electrophoresis, freeze etching and the novel use of electron microscopy, that much of the material of the cell wall is synthesized in cytoplasmic organelles before being transported to the developing wall in vesicles assembled from the membranes of the Golgi body. His findings inspired many colleagues to build on the foundation he laid for understanding the biochemistry of cell morphogenesis. Nearly his entire career was spent in fundamental research and teaching in the Department of Biochemistry, University of Cambridge, from 1948 until his retirement in 1992. In addition, he was a fellow of St John's College, Cambridge, from 1960 to 1976, and he served Sidney Sussex College, Cambridge, as master from 1976 to 1992.

The maturation of cell wall structure during germination of Bacillus polymyxa spores

1970 ◽  
Vol 16 (9) ◽  
pp. 883-887 ◽  
Author(s):  
R. G. E. Murray ◽  
Myrtle M. Hall ◽  
J. Marak
Keyword(s):  
Cell Wall ◽  
Intermediate Layer ◽  
Single Layer ◽  
Regular Structure ◽  
Wall Structure ◽  
Bacillus Polymyxa ◽  
Rectangular Array ◽  
Crack Open ◽  
Freeze Etching ◽  
Primordial Cell

Sections of germinating spores of Bacillus polymyxa show that the primordial cell wall consists of a single layer. The intermediate layer and an outer rectangular array of macromolecules found on vegetative cells do not appear until the spore coats crack open about 60 min after initiation of germination. The initial areas of the new components appear in patches under the cracks in the coats. Within 10 min the wall is completed and takes on the profile seen in the vegetative cell. Negative staining and freeze-etching techniques show the regular structure to be identical with that previously shown for mature cells, although the subunits are more readily visible in negatively stained preparations.

Fine Structure of Swarmers of Cladophora and Chaetomorpha

1971 ◽  
Vol 9 (3) ◽  
pp. 581-601
Author(s):  
D. G. ROBINSON ◽  
R. D. PRESTON
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Spatial Arrangement ◽  
Cell Wall Synthesis ◽  
Fibrous Layer ◽  
Etching Technique ◽  
Freeze Etching

Naked swarmers of both Cladophora rupestris and Chaetomorpha melagonium have been examined by the freeze-etching technique. The swarmers of Cladophora, collected just after settling, reveal several layers of granules external to the plasmalemma and internal to the so-called ‘fibrous-layer’. Chaetomorpha swarmers collected just before settling show extrusion of vesicles through the plasmalemma. The structures associated with the membranes are discussed in relation to known features of these swarmers already observed by sectioning. The role of granules in the synthesis of cell wall microfibrils is strengthened though the spatial arrangement of the granules seen in this investigation does not completely fulfil the ‘ordered granule’ hypothesis. Description of, and comments on, features related to cell wall synthesis, particularly the Golgi and vacuolar systems, are given.

A Simple Method for Removal of the Chlamydomonas reinhardtii Cell Wall Using a Commercially Available Subtilisin (Alcalase)

2018 ◽  
Vol 28 (4) ◽  
pp. 169-178 ◽  
Author(s):  
Hyun-Ju Hwang ◽  
Yong Tae Kim ◽  
Nam Seon Kang ◽  
Jong Won Han
Keyword(s):  
Cell Wall ◽  
Chlamydomonas Reinhardtii ◽  
Algal Cell ◽  
Chemical Properties ◽  
Transformation Method ◽  
Lytic Enzyme ◽  
Higher Plant ◽  
Time Saving ◽  
Simple Method ◽  
Cell Wall Disruption

The algal cell wall is a potent barrier for delivery of transgenes for genetic engineering. Conventional methods developed for higher plant systems are often unable to penetrate or remove algal cell walls owing to their unique physical and chemical properties. Therefore, we developed a simple transformation method for <i>Chlamydomonas reinhardtii</i> using commercially available enzymes. Out of 7 enzymes screened for cell wall disruption, a commercial form of subtilisin (Alcalase) was the most effective at a low concentration (0.3 Anson units/mL). The efficiency was comparable to that of gamete lytic enzyme, a protease commonly used for the genetic transformation of <i>C. reinhardtii</i>. The transformation efficiency of our noninvasive method was similar to that of previous methods using autolysin as a cell wall-degrading enzyme in conjunction with glass bead transformation. Subtilisin showed approximately 35% sequence identity with sporangin, a hatching enzyme of <i>C. reinhardtii</i>, and shared conserved active domains, which may explain the effective cell wall degradation. Our trans­formation method using commercial subtilisin is more reliable and time saving than the conventional method using autolysin released from gametes for cell wall lysis.

scholarly journals Hypolignification: A Decisive Factor in the Development of Hyperhydricity

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2625
Author(s):  
Nurashikin Kemat ◽  
Richard G. F. Visser ◽  
Frans A. Krens
Keyword(s):  
Cell Wall ◽  
Lignin Content ◽  
Coumaric Acid ◽  
Wild Type ◽  
Higher Plant ◽  
Gene Coding ◽  
Phenylpropanoid Biosynthesis ◽  
Total Lignin ◽  
Total Lignin Content

One of the characteristics of hyperhydric plants is the reduction of cell wall lignification (hypolignification), but how this is related to the observed abnormalities of hyperhydricity (HH), is still unclear. Lignin is hydrophobic, and we speculate that a reduction in lignin levels leads to more capillary action of the cell wall and consequently to more water in the apoplast. p-coumaric acid is the hydroxyl derivative of cinnamic acid and a precursor for lignin and flavonoids in higher plant. In the present study, we examined the role of lignin in the development of HH in Arabidopsis thaliana by checking the wild-types (Ler and Col-0) and mutants affected in phenylpropanoid biosynthesis, in the gene coding for cinnamate 4-hydroxylase, C4H (ref3-1 and ref3-3). Exogenously applied p-coumaric acid decreased the symptoms of HH in both wild-type and less-lignin mutants. Moreover, the results revealed that exogenously applied p-coumaric acid inhibited root growth and increased the total lignin content in both wild-type and less-lignin mutants. These effects appeared to diminish the symptoms of HH and suggest an important role for lignin in HH.

Radioautographic and Chemical Studies of Incorporation into Sycamore Vascular Tissue Walls

1968 ◽  
Vol 3 (1) ◽  
pp. 71-80
Author(s):  
F. B. P. WOODING
Keyword(s):  
Cell Wall ◽  
Vascular Tissue ◽  
Golgi Body ◽  
Cell Wall Polysaccharide ◽  
Polysaccharide Synthesis ◽  
Chemical Studies

Chemical and radioautographic studies on sycamore seedling stems have shown an involvement of the Golgi body in cell-wall polysaccharide synthesis from tritiated glucose. Tritiated phenylalanine is shown to be incorporated only into lignin after short incubation times. The patterns of labelling are compared and discussed for the two precursors.

Amycolatopsis dongchuanensis sp. nov., an actinobacterium isolated from soil

2012 ◽  
Vol 62 (Pt_11) ◽  
pp. 2650-2656 ◽  
Author(s):  
Guo-Xing Nie ◽  
Hong Ming ◽  
Shuai Li ◽  
En-Min Zhou ◽  
Juan Cheng ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Diaminopimelic Acid ◽  
Western China ◽  
Rrna Gene ◽  
The Novel ◽  
Biochemical Tests ◽  
Content Type ◽  
Link Type

A novel actinomycete strain, designated YIM 75904T, was isolated from a soil sample that had been collected from a dry and hot river valley in Dongchuan county, Yunnan province, south-western China. The taxonomic position of the novel strain was investigated by a polyphasic approach. In phylogenetic analyses based on 16S rRNA gene sequences, strain YIM 75904T formed a distinct clade within the genus Amycolatopsis and appeared to be closely related to Amycolatopsis sacchari K24T (99.3 % sequence similarity). Strain YIM 75904T had a type-IV cell wall, with no detectable mycolic acids, and had MK-9(H4) as its predominant menaquonine. Its cell wall contained meso-diaminopimelic acid, galactose, glucose and arabinose, and its major cellular fatty acids were iso-C16 : 0, iso-C15 : 0, anteiso-C17 : 0 and anteiso-C15 : 0. The genomic DNA G+C content of the novel strain was 68.5 mol%. Based on the results of physiological and biochemical tests and DNA–DNA hybridizations, strain YIM 75904T represents a novel species of the genus Amycolatopsis for which the name Amycolatopsis dongchuanensis sp. nov. is proposed. The type strain is YIM 75904T ( = CCTCC AA 2011016T  = JCM 18054T).

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