Calcium treatment of harvested Geraldton waxflower does not enhance postharvest quality

2003 ◽  
Vol 43 (6) ◽  
pp. 655 ◽  
Author(s):  
M. N. Taylor ◽  
D. C. Joyce ◽  
A. H. Wearing ◽  
D. H. Simons
Keyword(s):  
Cell Walls ◽  
Postharvest Quality ◽  
Vase Life ◽  
Plant Cell Walls ◽  
Calcium Treatment ◽  
Postharvest Application ◽  
Tissue Calcium ◽  
Structural Barrier ◽  
Flower Abscission ◽  
Chamelaucium Uncinatum

Postharvest flower abscission from cut Geraldton waxflower (Chamelaucium uncinatum) is mostly caused by fungal invasion. Elevated plant tissue calcium concentrations through postharvest application reduces fungal disease severity in various crops. Such results may be explained by strengthening of plant cell walls by calcium. Strengthening provides a structural barrier to fungal hyphae, thereby restricting invasion of plant cells. Postharvest pulsing with calcium solution substantially increased calcium concentrations in waxflower tissues. 45Ca�tracer revealed calcium distribution throughout flowering sprigs, including infection sites such as stylar tissue. However, pulsing waxflower sprigs with calcium did not suppress either disease or flower abscission, nor did it enhance vase life.

Postharvest floral organ fall in Geraldton waxflower (Chamelaucium uncinatum Schauer)

1993 ◽  
Vol 33 (4) ◽  
pp. 481 ◽  
Author(s):  
DC Joyce
Keyword(s):  
Water Deficit ◽  
Room Temperature ◽  
Floral Organ ◽  
Vase Life ◽  
Naphthaleneacetic Acid ◽  
Fungal Development ◽  
Compression Load ◽  
Severe Water Deficit ◽  
Flower Abscission ◽  
Chamelaucium Uncinatum

Possible reasons for, and prevention of, postharvest floral organ fall in Geraldton waxflower (Chamelaucium unciizatum Schauer) were studied. An 11-kg compression load, equivalent to the lidding of a carton, caused flower fall amounting to 1% of the fresh mass of 420-g bunches. Fungal development also resulted in flower abscission. Healthy flowers produced little ethylene (e.g. 0.05 �L/kg.h), while infected flowers produced much more (e.g. 7.71 �L/kg.h) and were shed. Treatment with fungicide (iprodione + mancozeb) and antiethylene compounds [e.g. silver thiosulfate (STS) pulse, Purafil sorbant] reduced flowerfall in packaged flowers. Cut sprigs which suffered severe water deficit also shed flowers. In cv. Elegance, drying to -3.61 MPa elevated ethylene production (e.g. 1.35 �L/kg . h). Flowerfall induced by water deficit could be reduced by pretreatment with a STS pulse (0.5 mmol Ag+/L for 15-22 h at 0�C or 4 mmol Ag+/L for 20-30 min at about 20�C). Pretreatment with a naphthaleneacetic acid dip (50 mg/L for 1 min at room temperature) shortened the vase life of Elegance.

scholarly journals Postharvest Handling of Cut Heuchera sanguinea Engelm. Flowers: Effects of Sucrose and Silver Thiosulfate

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 731-733 ◽  
Author(s):  
Susan S. Han
Keyword(s):  
Postharvest Quality ◽  
Vase Life ◽  
Flower Buds ◽  
Silver Thiosulfate ◽  
Postharvest Handling ◽  
Exogenous Ethylene ◽  
Flower Abscission

Postharvest quality of cut Heuchera sanguinea Engelm. `Splendens' and `Bressingham' was significantly improved and vase life significantly increased by pulsing the inflorescences with 4 mm silver thiosulfate (STS) for 4 hours followed by placing the stems in vase solutions containing 0.5% sucrose and 200 mg·L-1 8-hydroxyquinoline citrate. Under these conditions, nearly all of the buds (>92%) on inflorescences harvested with ≈2% to 3% open flowers developed to anthesis, in comparison with 26% to 28% of the controls. Sucrose concentrations higher than 1% were detrimental and resulted in stem toppling. Treatment with 4 mm STS for 4 hours delayed bud and flower abscission, but longer treatment times resulted in blackening and shriveling of the flower buds. With the absence of sucrose in the vase solutions, flower buds on STS-treated inflorescences did not continue to develop. Ethylene is probably involved in the natural senescence of the flower buds, since exogenous ethylene induced rapid flower abscission, and senescence was delayed by treatment with STS.

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.

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...

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

scholarly journals 24-Epibrasinolide Modulates the Vase Life of Lisianthus Cut Flowers by Modulating ACC Oxidase Enzyme Activity and Physiological Responses

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 995
Author(s):  
Mohammad Darvish ◽  
Habib Shirzad ◽  
Mohammadreza Asghari ◽  
Parviz Noruzi ◽  
Abolfazl Alirezalu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Water Absorption ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Postharvest Quality ◽  
Vase Life ◽  
Dependent Manner ◽  
Cut Flowers ◽  
Oxidase Enzyme

Ethylene is the most important factor playing roles in senescence and deterioration of harvested crops including cut flowers. Brassinosteroids (BRs), as natural phytohormones, have been reported to differently modulate ethylene production and related senescence processes in different crops. This study was carried out to determine the effects of different levels of 24-epibrassinolide (EBL) on ACC oxidase enzyme activity, the final enzyme in ethylene biosynthesis pathway, vase life, and senescence rate in lisianthus cut flowers. Harvested flowers were treated with EBL (at 0, 3, 6, and 9 µmol/L) and kept at 25 °C for 15 days. The ACC oxidase activity, water absorption, malondialdehyde (MDA) production and vase solution absorption rates, chlorophyll and anthocyanin contents, and the vase life of the flowers were evaluated during and at the end of storage. EBL at 3 µmol/L significantly (p ≤ 0.01) enhanced the flower vase life by decreasing the ACC oxidase activity, MDA production and senescence rates, and enhancing chlorophyll and anthocyanin biosynthesis and accumulation, relative water content, and vase solution absorption rates. By increasing the concentration, EBL negatively affected the flower vase life and postharvest quality probably via enhancing the ACC oxidase enzyme activity and subsequent ethylene production. EBL at 6 and 9 µmol/L and in a concentration dependent manner, enhanced the ACC oxidase activity and MDA production rate and decreased chlorophyll and anthocyanin accumulation and water absorption rate. The results indicate that the effects of brassinosteroids on ethylene production and physiology of lisianthus cut flowers is highly dose dependent.

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