KNAT7 regulates xylan biosynthesis in Arabidopsis seed-coat mucilage

2020 ◽  
Vol 71 (14) ◽  
pp. 4125-4139
Author(s):  
Yiping Wang ◽  
Yan Xu ◽  
Shengqiang Pei ◽  
Mingmin Lu ◽  
Yingzhen Kong ◽  
...  
Keyword(s):  
Plant Cell ◽  
Seed Coat ◽  
Cell Walls ◽  
Wall Structure ◽  
Plant Cell Walls ◽  
Arabidopsis Seed ◽  
Ideal System ◽  
Xylan Biosynthesis ◽  
Seed Coat Mucilage ◽  
Seed Mucilage

Abstract As a major hemicellulose component of plant cell walls, xylans play a determining role in maintaining the wall structure. However, the mechanisms of transcriptional regulation of xylan biosynthesis remain largely unknown. Arabidopsis seed mucilage represents an ideal system for studying polysaccharide biosynthesis and modifications of plant cell walls. Here, we identify KNOTTED ARABIDOPSIS THALIANA 7 (KNAT7) as a positive transcriptional regulator of xylan biosynthesis in seed mucilage. The xylan content was significantly reduced in the mucilage of the knat7-3 mutant and this was accompanied by significantly reduced expression of the xylan biosynthesis-related genes IRREGULAR XYLEM 14 (IRX14) and MUCILAGE MODIFIED 5/MUCILAGE-RELATED 21 (MUM5/MUCI21). Electrophoretic mobility shift assays, yeast one-hybrid assays, and chromatin immunoprecipitation with quantitative PCR verified the direct binding of KNAT7 to the KNOTTED1 (KN1) binding site [KBS,TGACAG(G/C)T] in the promoters of IRX7, IRX14, and MUM5/MUCI21 in vitro, in vivo, and in planta. Furthermore, KNAT7 directly activated the expression of IRX14 and MUM5/MUCI21 in transactivation assays in mesophyll protoplasts, and overexpression of IRX14 or MUM5/MUCI21 in knat7-3 partially rescued the defects in mucilage adherence. Taken together, our results indicate that KNAT7 positively regulates xylan biosynthesis in seed-coat mucilage via direct activation of the expression of IRX14 and MUM5/MUCI21.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Cell-wall studies in the Chlorophyceae l. A preliminary study of the effect of continuous illumina­tion on wall structure in Cladophora rupestris

1953 ◽  
Vol 141 (904) ◽  
pp. 407-419 ◽  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Cell Walls ◽  
Continuous Illumination ◽  
Fibrillar Structure ◽  
Wall Structure ◽  
Plant Cell Walls ◽  
X Ray ◽  
Polarization Optics ◽  
Preliminary Study

Cultures of Cladophora rupestris under continuous illumination, for periods up to six months, have shown that the wall structure is modified as compared with control cultures with more normal illumination. This has been demonstrated by means of X-ray analysis and by polarization optics, and supported by ancillary observations oh both cultures. Under continuous illumination transverse microfibrils are laid down much more abundantly than are the longitudinal microfibrils. This may form the first step towards an understanding of the genesis of the crossed fibrillar structure of plant cell walls.

Wheat cell walls and constituent polysaccharides induce similar microbiota profiles upon in vitro fermentation despite different short chain fatty acid end-product levels.

2021 ◽  
Author(s):  
Shiyi Lu ◽  
Deirdre Mikkelsen ◽  
Hong Yao ◽  
Barbara Williams ◽  
Bernadine Flanagan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Gut Microbiota ◽  
Plant Cell ◽  
Cell Walls ◽  
Short Chain Fatty Acid ◽  
Chain Fatty Acid ◽  
Plant Cell Walls ◽  
Human Gut ◽  
In Vitro Fermentation

Plant cell walls as well as their component polysaccharides in foods can be utilized to alter and maintain a beneficial human gut microbiota, but it is not known whether the...

Galactoglucomannan structure of Arabidopsis seed‐coat mucilage in GDP ‐mannose synthesis impaired mutants

2021 ◽  
Author(s):  
Naho Nishigaki ◽  
Yoshihisa Yoshimi ◽  
Hiroaki Kuki ◽  
Tadashi Kunieda ◽  
Ikuko Hara‐Nishimura ◽  
...  
Keyword(s):  
Seed Coat ◽  
Arabidopsis Seed ◽  
Seed Coat Mucilage

scholarly journals Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1263
Author(s):  
David Stuart Thompson ◽  
Azharul Islam
Keyword(s):  
Cell Wall ◽  
Water Content ◽  
Bacterial Cellulose ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Plant Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Degree Of Hydration ◽  
Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

Glycoprotein conformation in plant cell walls

Planta ◽  
1979 ◽  
Vol 146 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Roger B. Homer ◽  
Keith Roberts
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls
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