RELATIONSHIP BETWEEN EPICUTICULAR WAX AND BLACKSPOT CAUSED BY ALTERNARIA BRASSICAE IN THREE LINES OF RAPESEED

1976 ◽  
Vol 56 (4) ◽  
pp. 781-785 ◽  
Author(s):  
J. P. TEWARI ◽  
W. P. SKOROPAD
Keyword(s):  
Partial Resistance ◽  
Leaf Surface ◽  
Epicuticular Wax ◽  
Water Repellent ◽  
Minimal Amount ◽  
Alternaria Brassicae ◽  
Brassica Napus L ◽  
Physical Role ◽  
Wax Crystals

The physical role of epicuticular wax in rapeseed in conferring resistance to Alternaria brassicae (Berk.) Sacc. has been investigated using the adaxial surface of the upper leaves of three lines of rapeseed. The lines of rapeseed were selected to offer a range of bloom and degrees of resistance to A. brassicae. Scanning electron microscopy revealed that epicuticular wax is organized in two layers. The distal layer is fluffy and consists of cylindrical wax crystals, while the proximal layer has plate-like wax crystals. The distal layer is thicker in the Iowa line (Brassica napus L.) than in the cv. Midas (B. napus), while the proximal layer is almost similar in the two cultivars. Torch (B. campestris L.) has only a minimal amount of wax. Wiping of the leaves with cotton wool removes the fluffy wax layer. The amount of wax per cm2 of the leaf surface is maximum in the Iowa line, followed by that in Midas and Torch. The contact angle of water droplets is significantly reduced and retention of conidia and development of blackspots caused by A. brassicae are significantly increased upon wiping of the leaves in Iowa line and Midas but not in Torch. It is concluded that the bloom in rapeseed confers partial resistance to A. brassicae by providing a water-repellent surface.

Micromorphology of Johnsongrass (Sorghum halepense) Leaves

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 583-589 ◽  
Author(s):  
Chester G. Mcwhorter ◽  
Clark Ouzts ◽  
Rex N. Paul
Keyword(s):  
Leaf Surface ◽  
Epicuticular Wax ◽  
Epidermal Cells ◽  
Sorghum Halepense ◽  
Single Type ◽  
Cork Cell ◽  
Silica Cell ◽  
Stomatal Complexes ◽  
Epicuticular Wax Crystals ◽  
Wax Crystals

Adaxial and abaxial epidermal surfaces of johnsongrass leaves were studied to determine which cells contribute to leaf microroughness. Cork-silica cell (CSC) pairs, three types of prickles, macrohairs, bicellular trichomes, stomata, and ordinary short and long epidermal cells were found and described. CSC pairs made up about 22% of all cells and probably contribute more to microroughness than any other single type because each cork cell produces 11 ± 3 wax filaments that are up to 100 μm long. Bicellular trichomes represented 4 to 5% of the total cells but decreased leaf roughness by secreting a type of mucilage that covers microscopic wax crystals. Stomatal complexes comprised 15 to 18% of all cells and contributed to leaf roughness because they are slightly recessed below the leaf surface. Long prickles occur primarily over veins and represent less than 1% of all cells. Small prickles were present primarily on adaxial surfaces and represent only 3% of all cells. Macrohairs were the largest appendages, 237 ± 104 μm, but they represent far less than 1% of all cells and occur primarily over veins. Ordinary short cells comprised 6 to 13% of all cells. Long cells were most common (41%) of all cells. Short and long cells contribute to leaf roughness because the surface is often convex. A typical johnsongrass leaf may contain more than 25 million appendages on each surface that increase the roughness already caused by epicuticular wax crystals.

FIELD EVALUATION OF THE ROLE OF EPICUTICULAR WAX IN RAPESEED AND MUSTARD IN RESISTANCE TO ALTERNARIA BLACKSPOT

1977 ◽  
Vol 57 (3) ◽  
pp. 1001-1003 ◽  
Author(s):  
W. P. SKOROPAD ◽  
J. P. TEWARI
Keyword(s):  
Disease Susceptibility ◽  
Brassica Campestris ◽  
Field Evaluation ◽  
Epicuticular Wax ◽  
Field Conditions ◽  
Alternaria Brassicae ◽  
Cotton Swab

The role of epicuticular wax in conferring resistance to blackspot, incited by Alternaria brassicae (Berk.) Sacc, has been investigated under field conditions in four cultivars of rapeseed and mustard. In increasing order of resistance to blackspot they were: Torch (Brassica campestris L.), Midas (B. napus L), Lethbridge (LB) 22A (B. juncea (L.) Czern.), and Tower (B. napus). The leaves of Midas and Tower have appreciable amounts of epicuticular wax, and wiping of the leaves with a dry cotton swab significantly increases their susceptibility to the blackspot disease. Torch and LB 22A have minimal amounts of epicuticular wax and their disease susceptibility is generally not significantly altered upon wiping. It is concluded that the epicuticular wax in rapeseed and mustard confers resistance to blackspot and that this character could be used in breeding cultivars resistant to this disease.

The role of shearing effect in evolution of the microscopic behavior of wax crystals

2021 ◽  
Author(s):  
Yuanhao Li ◽  
Jian Zhao ◽  
Hang Dong ◽  
Xiangrui Xi
Keyword(s):  
Crude Oil ◽  
Waxy Crude Oil ◽  
Waxy Crude ◽  
Dynamical Behaviors ◽  
Physical Phenomena ◽  
Wax Crystals

The microstructure and dynamical behaviors of wax crystals in waxy crude oil are the fundamental reasons for a series of physical phenomena in the process of transportation. In order to...

Quantitative Determination of the Role of Lettuce Leaf Structures in Protecting Escherichia coli O157:H7 from Chlorine Disinfection

2001 ◽  
Vol 64 (2) ◽  
pp. 147-151 ◽  
Author(s):  
KAZUE TAKEUCHI ◽  
JOSEPH F. FRANK
Keyword(s):  
Escherichia Coli ◽  
Leaf Surface ◽  
Dead Cell ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Chlorine Disinfection ◽  
Sytox Green ◽  
Tissue Surface ◽  
Confocal Scanning

Viability of Escherichia coli O157:H7 cells on lettuce leaves after 200 mg/liter (200 ppm) chlorine treatment and the role of lettuce leaf structures in protecting cells from chlorine inactivation were evaluated by confocal scanning microscopy (CSLM). Lettuce samples (2 by 2 cm) were inoculated by immersing in a suspension containing 109 CFU/ml of E. coli O157: H7 for 24 ± 1 h at 4°C. Rinsed samples were treated with 200 mg/liter (200 ppm) chlorine for 5 min at 22°C. Viability of E. coli O157:H7 cells was evaluated by CSLM observation of samples stained with Sytox green (dead cell stain) and Alexa 594 conjugated antibody against E. coli O157:H7. Quantitative microscopic observations of viability were made at intact leaf surface, stomata, and damaged tissue. Most E. coli O157:H7 cells (68.3 ± 16.2%) that had penetrated 30 to 40 μm from the damaged tissue surface remained viable after chlorine treatment. Cells on the surface survived least (25.2 ± 15.8% survival), while cells that penetrated 0 to 10 μm from the damaged tissue surface or entered stomata showed intermediate survival (50.8 ± 13.5 and 45.6 ± 9.7% survival, respectively). Viability was associated with the depth at which E. coli O157:H7 cells were in the stomata. Although cells on the leaf surface were mostly inactivated, some viable cells were observed in cracks of cuticle and on the trichome. These results demonstrate the importance of lettuce leaf structures in the protection of E. coli O157:H7 cells from chlorine inactivation.

The Role of Leaf Epicuticular Wax in the Adaptation of Wheat ( Triticum aestivum L.) to High Temperatures and Moisture Deficit Conditions

Crop Science ◽  
2018 ◽  
Vol 58 (2) ◽  
pp. 679-689 ◽  
Author(s):  
Suheb Mohammed ◽  
Trevis D. Huggins ◽  
Francis Beecher ◽  
Chris Chick ◽  
Padma Sengodon ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
High Temperatures ◽  
Triticum Aestivum L ◽  
Epicuticular Wax ◽  
Moisture Deficit ◽  
Leaf Epicuticular Wax

scholarly journals THE ROLE OF FLAG LEAVES AND AWNS IN THE FORMATION OF WINTER WHEAT PRODUCTIVITY (REVIEW)

2018 ◽  
pp. 32-34 ◽  
Author(s):  
S. N. Gromova ◽  
P. I. Kostylev
Keyword(s):  
Winter Wheat ◽  
Leaf Surface ◽  
Wheat Yield ◽  
Complex Trait ◽  
Genetic System ◽  
Flag Leaves ◽  
Grain Productivity ◽  
Agricultural Yield ◽  
Yield Formation

The article presents the results of the conducted analysis of research works about the effect of size of flag leaves and awns on winter wheat productivity. The genetic potential of the variety, which can be realized on the basis of its biologic characteristics largely influences on its productivity. Productivity is a complex trait that is controlled by a complex genetic system closely connected with many factors of environment. The size and duration of assimilation surface are the most important components of biologic and agricultural yield of wheat. Many researchers showed that the amount and duration of photosynthesis by leaf surface are the main factors limiting productivity in the definite conditions of growing, and the size of leaf surface correlates with grain productivity. Photosynthetic parts of winter wheat include not only leaves, but also stems, heads, awns, etc. The conducted analysis of the literature showed that there is no consensus on the effect of flag leaves on wheat yield formation. Therefore it’s necessary to fulfill the study and evaluation of the part of flag leaves and awns in the formation of winter soft wheat productivity in the Rostov region.

Genera of Gymnodamaeidae (Acari: Oribatida: Plateremaeoidea) of Canada, with notes on some nomenclatorial problems

Zootaxa ◽  
2009 ◽  
Vol 2206 (1) ◽  
pp. 23-44 ◽  
Author(s):  
DAVID EVANS WALTER
Keyword(s):  
North American ◽  
Epicuticular Wax ◽  
North American Species ◽  
Nelumbo Nucifera ◽  
Water Repellent ◽  
Lotus Effect ◽  
The North

The taxonomy of the North American Gymnodamaeidae is currently intractable, because (1) the adults are covered in a thick, ornamented cerotegument that provides useful characters, but that obscures the cuticle; (2) many descriptions appear to be based on newly moulted or cleared specimens and are incomplete or contain misinterpretations; and (3) there is considerable disagreement in the literature about valid genera and generic limits, leading some authors to sink some or all of the North American genera into Gymnodamaeus s.l. Several nomenclatorial problems have added to the confusion. In this paper I use new diagnoses to demonstrate that seven previously described genera based on North American species can be separated from Gymnodamaeus s.s. and provide a key to distinguish them. I clarify the correct publication dates for Paschoal’s genera and after consultation with the original author, propose replacements for two of these generic names that are preoccupied: Donjohnstonella nom. nov. for Johnstonella Paschoal and Roynortonella nom. nov. for Nortonella Paschoal. New Canadian provincial distribution records are provided for Gymnodamaeus cf. ornatus Hammer (AB), Jacotella quadricaudicula (Jacot) (AB, ON), Joshuella agrosticula Paschoal (AB, YK), and Pleodamaeus plokosus (Woolley & Higgins) (AB). Finally, I discuss the similarity between the cerotegumental pustules in the Gymnodamaeidae and the epicuticular wax crystalloids on the leaves of plants such as the water lotus (Nelumbo nucifera Gaertn.) and suggest that they may have a similar water repellent “Lotus-effect.

scholarly journals Knockout of the neonatal Fc receptor in cultured podocytes alters IL-6 signaling and the actin cytoskeleton

2019 ◽  
Vol 317 (5) ◽  
pp. C1048-C1060 ◽  
Author(s):  
Pantipa Tonsawan ◽  
James Dylewski ◽  
Linda Lewis ◽  
Judith Blaine
Keyword(s):  
Immune Complexes ◽  
Fc Receptor ◽  
Actin Dynamics ◽  
Minimal Amount ◽  
Neonatal Fc Receptor ◽  
Scratch Assay ◽  
Immune Mediated ◽  
Actin Structure ◽  
Robust Response

The neonatal Fc receptor (FcRn) has been shown to be required for antigen presentation in dendritic cells, and global knockout of FcRn attenuates immune-mediated kidney disease. Podocytes express interleukin-6 (IL-6) receptor and produce IL-6 under proinflammatory conditions. Here we examined the role of FcRn in the IL-6-mediated inflammatory response in podocytes. We examined IL-6 production by ELISA and expression by qPCR in wild type (WT) and FcRn knockout (KO) podocytes after treatment with proinflammatory stimuli as well as IL-6-mediated signaling via the JAK/STAT pathway. We also examined podocyte motility in cultured WT and KO podocytes after a proinflammatory challenge. We found that FcRn KO podocytes produced minimal amount of IL-6 after treatment with albumin, IgG, or immune complexes whereas WT podocytes had a robust response. FcRn KO podocytes also had minimal expression of IL-6 compared with WT. By Western blotting, there was significantly less phosphorylated STAT3 in KO podocytes after treatment with IFNγ or immune complexes. In a scratch assay, FcRn KO podocytes showed increased motility comparted KO, suggesting a defect in actin dynamics. Cultured FcRn KO podocytes also demonstrated abnormal stress fibers compared with WT and the defect could be rescued by IL-6 treatment. This study shows that in podocytes, FcRn modulates the IL-6 mediated response to proinflammatory stimuli and regulates podocytes actin structure, motility and synaptopodin expression.

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