the aim of this paper was to assess the effect of catechol (ch), as a peroxidase inhibitor, and 8-hydroxyquinoline citrate (hqc), as a bacterial inhibitor, on keeping the quality of gerbera jamesonii cv. hongyan cut flowers, known to be limited by vascular occlusion. blockage in the stem xylem vessels of cut gerbera was studied using light and scanning electron microscope. the results showed th...

A temperature-dependent xylem occlusion was found in cut chrysanthemum stems (Dendranthema grandiflora, cv. Viking) which were placed for 24 h in air at 5°C prior to vase life evaluation. The response was inhibited by a 5-h treatment, prior to placement in air, with aqueous solutions at low initial pH or solutions containing near-neutral antioxidants (n-propylgallate, phloroglucinol, butylated ...

Laterally connected vascular bundles in the nodes of sugarcane (Saccharum species cv. Pindar) stalks allow a rapid redistribution of water across the stalk should the vascular continuity be partly disrupted. Tritiated water supplied to the roots exchanged rapidly between the xylem and storage tissue so that net movement up the stalk was slow. The half-time for exchange in a labeled stalk was ab...

We investigated the effects of sucrose and nano-silver (NAg) on extending the vase life of cut carnation flowers "Edun". Sucrose (pulse treatment) suppressed ethylene production by downregulating the genes that code for its biosynthesis. Relative to the control, however, sucrose significantly promoted xylem blockage on cut stem surfaces and reduced relative fresh weight, antioxidant activity, a...

We discuss the relationship between the dynamically changing tension gradients required to move water rapidly through the xylem conduits of plants and the proportion of conduits lost through embolism as a result of water tension. We consider the implications of this relationship to the water relations of trees. We have compiled quantitative data on the water relations, hydraulic architecture an...

The aim of this paper was to assess the effect of catechol (CH), as a peroxidase inhibitor, and 8-hydroxyquinoline citrate (HQC), as a bacterial inhibitor, on keeping the quality of Gerbera Jamesonii cv. Hongyan cut flowers, known to be limited by vascular occlusion. Blockage in the stem xylem vessels of cut gerbera was studied using light and scanning electron microscope. The results showed th...

Hydraulic conductivity of the xylem is computed as the quotient of mass fiow rate and pressure gradient. Measurements on excised plant stems can be difficult to interpret because of timedependent reductions in fiow rate, and because of variable degrees of embolism. Using Acer saccharum Marsh, stems, we found that certain perfusing solutions including dilute fixatives (e.g. 0.05% formaldehyde) a...

the vase life of cut flowers and foliage is often shortened by vascular occlusions that constrict vase solution supply. reduction in stem conductivity is typically caused by blockage of cut stem ends and xylem conduits by microbes, physiological plugging, and disruption of water columns in xylem vessels by cavitations and air emboli. cut flower and foliage longevity can be greatly affected by t...

It is conventionally thought that multiplication of the xylem-limited bacterium Xylella fastidiosa (Xf) within xylem vessels is the sole factor responsible for the blockage of water movement in grapevines (Vitis vinifera) affected by Pierce's disease. However, results from our studies have provided substantial support for the idea that vessel obstructions, and likely other aspects of the Pierce...

Our investigation focused on aggregation and ‘autoaggregation’of Xylella fastidiosa (Xf) cells. This study is particularly directed toward elucidating how Xf cells aggregate to cause PD symptoms. We have documented that both type IV and type I pili are important in the process. Furthermore, it was discerned that surface properties of WT cells change from being more hydrophobic to more hydrophil...