scholarly journals RIMAPS and Varlogram Analysis of Barley Leaf Surfaces

2004 ◽  
Vol 12 (5) ◽  
pp. 24-27 ◽  
Author(s):  
Eduardo A. Favret ◽  
Néstor O. Fuentes
Keyword(s):  
Quantitative Method ◽  
Average Power ◽  
Plant Tissues ◽  
Wild Type ◽  
Abaxial Side ◽  
Leaf Surfaces ◽  
Barley Leaves ◽  
Leaf Mutant ◽  
Barley Leaf ◽  
Average Power Spectrum

It is a common practice to use microscopic images to describe the differences observed between plant tissues. The images illustrate the taxonomic characteristics of the studied species. In this work we introduce a quantitative method for conducting these analyses utilizing digitized images obtained via scanning electron microscopy (SEM) of barley leaf surfaces. The topography of the leaf surfaces of a narrow-leaf mutant and its wild type mother line was characterized, see figure 1, using the Rotated Image with Maximum Average Power Spectrum (RIMAPS) technique and the Variogram method. Spectra resulting from RIMAPS analysis allow us to identify the specimens and to distinguish between the adaxial or the abaxial side of the leaf. These results are complemented by obtaining the typical scale lengths that characterize the abaxial surfaces of both the mutant and the mother line barley leaves.

Role of adhesion in the colonization of barley leaves by the yeastRhodosporidium toruloides

1999 ◽  
Vol 45 (6) ◽  
pp. 433-440 ◽  
Author(s):  
James W Buck ◽  
John H Andrews
Keyword(s):  
Leaf Surface ◽  
Rhodotorula Glutinis ◽  
Surface Characteristics ◽  
Wild Type ◽  
Two Phase ◽  
Leaf Surfaces ◽  
Barley Leaves ◽  
Major Factors

To investigate whether leaf-surface yeasts adhere to the phylloplane in a two-phase manner, with weak, nonspecific attachment followed by stronger, time-dependent adhesion, we observed adhesion kinetics of the basidiomycete yeast Rhodosporidium toruloides to barley. While 50-60% of the cells adhered in short-term assays (up to 3 h), fewer than 10% were adherent after 10 days. Ten attachment-minus (Att-) mutants, deficient in phase I attachment, did not adhere after 5-day incubations, further suggesting a lack of stronger, independent phase II adhesion. Long-term (5 day) adhesion was similar for two isolates of R. toruloides and the ubiquitous leaf-surface fungus Aureobasidium pullulans. Long-term adhesion of R. toruloides to leaves of a waxless barley mutant was significantly greater than to leaves of the wild-type cv. Bonus. Application of exogenous nutrients (dilute yeast carbon base) to resident, wild-type R. toruloides populations resulted in both a rapid recolonization to the apparent carrying capacity of the leaves and an increase in the total adherent populations. Att-mutants recolonized barley segments, when supplied with nutrients, after more than 99% of the cells had been removed by agitation. Therefore, adhesion of R. toruloides to leaves was not required for subsequent colonization of the phylloplane. Overall, these data suggest that the frequency of yeast emigration from leaf surfaces, microbial growth rates, and leaf surface characteristics are major factors influencing colonization of leaf surfaces.Key words: epiphyte, phylloplane, Rhodotorula glutinis.

Lack of Internalization of Escherichia coli O157:H7 in Lettuce (Lactuca sativa L.) after Leaf Surface and Soil Inoculation

2009 ◽  
Vol 72 (10) ◽  
pp. 2028-2037 ◽  
Author(s):  
GUODONG ZHANG ◽  
LI MA ◽  
LARRY R. BEUCHAT ◽  
MARILYN C. ERICKSON ◽  
VANESSA H. PHELAN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Leaf Surface ◽  
Escherichia Coli O157 ◽  
Adaxial Side ◽  
Abaxial Side ◽  
E Coli ◽  
Lactuca Sativa L ◽  
Leaf Surfaces ◽  
Leaves And Roots ◽  
Leaf Lettuce

Survival and internalization characteristics of Escherichia coli O157:H7 in iceberg, romaine, and leaf lettuce after inoculation of leaf surfaces and soil were determined. A five-strain mixture of E. coli O157:H7 in water and cow manure extract was used as an inoculum for abaxial and adaxial sides of leaves at populations of 6 to 7 log and 4 log CFU per plant. The five strains were individually inoculated into soil at populations of 3 and 6 log CFU/g. Soil, leaves, and roots were analyzed for the presence and population of E. coli O157:H7. Ten (4.7%) of 212 samples of leaves inoculated on the adaxial side were positive for E. coli O157:H7, whereas 38 (17.9%) of 212 samples inoculated on the abaxial side were positive. E. coli O157:H7 survived for at least 25 days on leaf surfaces, with survival greater on the abaxial side of the leaves than on the adaxial side. All 212 rhizosphere samples and 424 surface-sanitized leaf and root samples from plants with inoculated leaves were negative for E. coli O157:H7, regardless of plant age at the time of inoculation or the location on the leaf receiving the inoculum. The pathogen survived in soil for at least 60 days. Five hundred ninety-eight (99.7%) of 600 surface-sanitized leaf and root samples from plants grown in inoculated soil were negative for E. coli O157:H7. Internalization of E. coli O157:H7 in lettuce leaves and roots did not occur, regardless of the type of lettuce, age of plants, or strain of E. coli O157:H7.

Description and interpretation of the bracts epidermis of Gramineae (Poaceae) with rotated image with maximum average power spectrum (RIMAPS) technique

Micron ◽  
2008 ◽  
Vol 39 (7) ◽  
pp. 985-991 ◽  
Author(s):  
Eduardo A. Favret ◽  
Néstor O. Fuentes ◽  
Ana M. Molina ◽  
Lorena M. Setten
Keyword(s):  
Power Spectrum ◽  
Average Power ◽  
Average Power Spectrum

Study on Fast Algorithm for SNR and Method for Threshold Confirmation

2013 ◽  
Vol 427-429 ◽  
pp. 1718-1722
Author(s):  
Lin Sun ◽  
Ran Wei ◽  
Fu Ting Bao ◽  
Xian Zhang Tian
Keyword(s):  
Power Spectrum ◽  
Fast Algorithm ◽  
Human Gene ◽  
Signal To Noise Ratio ◽  
Average Power ◽  
Threshold Value ◽  
Computational Experiments ◽  
Rigorous Derivation ◽  
Signal To Noise ◽  
Average Power Spectrum

To reduce the amount of computing resources, a fast algorithm of the average power spectrum and signal-to-noise ratio was presented based on rigorous derivation of the formula. Also, it proved the rule gained from computational experiments. Besides, a method called fitting-optimization to determine the classification threshold value was proposed. It improves the accuracy by about 7% for human gene.

scholarly journals The Hypoxic Proteome and Metabolome of Barley (Hordeum vulgare L.) with and without Phytoglobin Priming

2020 ◽  
Vol 21 (4) ◽  
pp. 1546 ◽  
Author(s):  
Olga A. Andrzejczak ◽  
Jesper F. Havelund ◽  
Wei-Qing Wang ◽  
Sergey Kovalchuk ◽  
Christina E. Hagensen ◽  
...  
Keyword(s):  
Hordeum Vulgare ◽  
Metabolic Effects ◽  
Plant Tissues ◽  
Ros Production ◽  
Ion Transporters ◽  
Wild Type ◽  
Golden Promise ◽  
Hordeum Vulgare L ◽  
Plant Hemoglobins ◽  
Hypoxia Treatment

Overexpression of phytoglobins (formerly plant hemoglobins) increases the survival rate of plant tissues under hypoxia stress by the following two known mechanisms: (1) scavenging of nitric oxide (NO) in the phytoglobin/NO cycle and (2) mimicking ethylene priming to hypoxia when NO scavenging activates transcription factors that are regulated by levels of NO and O2 in the N-end rule pathway. To map the cellular and metabolic effects of hypoxia in barley (Hordeum vulgare L., cv. Golden Promise), with or without priming to hypoxia, we studied the proteome and metabolome of wild type (WT) and hemoglobin overexpressing (HO) plants in normoxia and after 24 h hypoxia (WT24, HO24). The WT plants were more susceptible to hypoxia than HO plants. The chlorophyll a + b content was lowered by 50% and biomass by 30% in WT24 compared to WT, while HO plants were unaffected. We observed an increase in ROS production during hypoxia treatment in WT seedlings that was not observed in HO seedlings. We identified and quantified 9694 proteins out of which 1107 changed significantly in abundance. Many proteins, such as ion transporters, Ca2+-signal transduction, and proteins related to protein degradation were downregulated in HO plants during hypoxia, but not in WT plants. Changes in the levels of histones indicates that chromatin restructuring plays a role in the priming of hypoxia. We also identified and quantified 1470 metabolites, of which the abundance of >500 changed significantly. In summary the data confirm known mechanisms of hypoxia priming by ethylene priming and N-end rule activation; however, the data also indicate the existence of other mechanisms for hypoxia priming in plants.

scholarly journals Physiological and transcriptomic characterization of a yellow-green leaf mutant of maize

2020 ◽  
Author(s):  
Tingchun Li ◽  
Huaying Yang ◽  
Yan Lu ◽  
Qing Dong ◽  
Guihu Liu ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Transcriptome Analysis ◽  
Green Leaf ◽  
Wild Type ◽  
Chlorophyll Metabolism ◽  
Chlorophyll Fluorescence Parameters ◽  
Chlorophyll Contents ◽  
Leaf Mutant ◽  
Photochemical Quantum Yield ◽  
Quantum Yield Of Psii

Abstract Background Chlorophylls, green pigments in chloroplasts, are essential for photosynthesis. Reduction in chlorophyll contents may result in retarded growth, dwarfism, and sterility. In this study, a yellow-green leaf mutant of maize, indicative of abnormity in chlorophyll contents, was identified. The physiological parameters of this mutant were measured. Next, global gene expression of this mutant was determined using transcriptome analysis and compared to that of wild-type maize plants. Results The yellow-green leaf mutant of maize was found to contain lower contents of chlorophyll a , chlorophyll b and carotenoid compounds. It contained fewer active PSII centers and displayed lower values of original chlorophyll fluorescence parameters than the wild-type plants. The real-time fluorescence yield, the electron transport rate, and the net photosynthetic rate of the mutant plants showed reduction as well. In contrast, the maximum photochemical quantum yield of PSII of the mutant plants was similar to that of the wild-type plants. Comparative transcriptomic analysis of the mutant plants and wild-type plants led to the identification of differentially expressed1122 genes, of which 536 genes were up-regulated and 586 genes down-regulated in the mutant. Five genes in chlorophyll metabolism pathway, nine genes in the tricarboxylic acid cycle and seven genes related to the conversion of sucrose to starch displayed down-regulated expression. In contrast, genes encoding a photosystem II reaction center PsbP family protein and the PGR5-like protein 1A (PGRL1A) exhibited increased transcript abundance. Conclusions The yellow-green leaf mutant of maize contained fewer active PSII centers with lowered net photosynthesis rate, but have the similar value of the maximum photochemical quantum yield of PSII with that of the wild-type plants. Analysis of differentially expressed genes through transcriptome analysis revealed the down-regulated genes which may be responsible for chlorophyll deduction and changes of photosynthetic characteristics. The up-regulated genes would be helpful to maintain the active PSII centers of the yellow-green leaf mutant.

scholarly journals Interaction of surfactants with barley leaf surfaces: time-dependent recovery of contact angles is due to foliar uptake of surfactants

Planta ◽  
2021 ◽  
Vol 255 (1) ◽  
Author(s):  
Johanna Baales ◽  
Viktoria V. Zeisler-Diehl ◽  
Yaron Malkowsky ◽  
Lukas Schreiber
Keyword(s):  
Leaf Surface ◽  
Pure Water ◽  
Contact Angles ◽  
Time Dependent ◽  
Alcohol Ethoxylate ◽  
Leaf Physiology ◽  
Surfactant Solutions ◽  
Surface Wax ◽  
Leaf Surfaces ◽  
Barley Leaf

Abstract Main conclusion Time-dependent contact angle measurements of pure water on barley leaf surfaces allow quantifying the kinetics of surfactant diffusion into the leaf. Abstract Barley leaf surfaces were sprayed with three different aqueous concentrations (0.1, 1.0 and 10%) of a monodisperse (tetraethylene glycol monododecyl ether) and a polydisperse alcohol ethoxylate (BrijL4). After 10 min, the surfactant solutions on the leaf surfaces were dry leading to surfactant coverages of 1, 10 and 63 µg cm−2, respectively. The highest surfactant coverage (63 µg cm−2) affected leaf physiology (photosynthesis and water loss) rapidly and irreversibly and leaves were dying within 2–6 h. These effects on leaf physiology did not occur with the lower surfactant coverages (1 and 10 µg cm−2). Directly after spraying of 0.1 and 1.0% surfactant solution and complete drying (10 min), leaf surfaces were fully wettable for pure water and contact angles were 0°. Within 60 min (0.1% surfactant) and 6 h (1.0% surfactant), leaf surfaces were non-wettable again and contact angles of pure water were identical to control leaves. Scanning electron microscopy investigations directly performed after surfactant spraying and drying indicated that leaf surface wax crystallites were partially or fully covered by surfactants. Wax platelets with unaltered microstructure were fully visible again within 2 to 6 h after treatment with 0.1% surfactant solutions. Gas chromatographic analysis showed that surfactant amounts on leaf surfaces continuously disappeared over time. Our results indicate that surfactants, applied at realistic coverages between 1 and 10 µg cm−2 to barley leaf surfaces, leading to total wetting (contact angles of 0°) of leaf surfaces, are rapidly taken up by the leaves. As a consequence, leaf surface non-wettability is fully reappearing. An irreversible damage of the leaf surface fine structure leading to enhanced wetting and increased foliar transpiration seems highly unlikely at low surfactant coverages of 1 µg cm−2.

scholarly journals First Report of Rust Caused by Puccinia nakanishikii on Lemongrass, Cymbopogon citratus, in Florida

Plant Disease ◽  
2014 ◽  
Vol 98 (1) ◽  
pp. 156-156
Author(s):  
R. C. Ploetz ◽  
A. J. Palmateer ◽  
P. Lopez ◽  
M. C. Aime
Keyword(s):  
Dna Analysis ◽  
Large Subunit ◽  
South Florida ◽  
Dade County ◽  
Cymbopogon Citratus ◽  
Abaxial Side ◽  
First Report ◽  
Leaf Surfaces ◽  
Voucher Specimens ◽  
The Tropics

Lemongrass, Cymbopogon citratus (DC.) Stapf. (Poaceae), is grown widely in the tropics and subtropics as an ornamental, flavoring ingredient in Asian cooking, and for tea and fragrant oil (3). In February 2013, rust symptoms were observed on lemongrass in several gardens in Miami-Dade County, Florida. Symptoms began as small chlorotic flecks on both leaf surfaces that became crimson and enlarged to streaks ~1 cm in length. On the abaxial side of leaves, erumpent streaks ruptured to produce pustules in which urediniospores formed. Eventually, streaks coalesced to produce large patches of tan to purplish necrotic tissue that blighted most of the leaf surface and was often surrounded by chlorotic borders. These symptoms, fungal morphology, and nuclear ribosomal large subunit (28S) DNA analysis were used to identify the pathogen as Puccinia nakanishikii Dietel. Urediniospores were pyriform to globose, orange to crimson, slightly echinulate, and somewhat longer than a previous report (32.1 ± 3.4 (27 to 42) × 23.3 ± 2.4 (21 to 27) μm vs. 22 to 28 × 22 to 25 μm) (2). Uredinia contained clavate paraphyses, but teliospores were not observed. No aecial host is known for this pathogen. A 28S DNA sequence that was generated with the NL1 and LR3 primers (1,4) was deposited in GenBank under accession no. KC990123; it shared 99% identity with GenBank accession GU058002, which came from a specimen of P. nakanishikii in Hawaii. Voucher specimens of affected leaves of lemongrass have been deposited at the Arthur Herbarium, Purdue University. Although this disease has been reported in California, Hawaii, New Zealand, and Thailand, this is believed to be the first report from Florida (2). Based on rainfall and temperature conditions that are conducive to its development in South Florida, it has the potential to significantly reduce the health and production of this plant in area gardens. References: (1) C. P. Kurtzman and C. J. Robnett. Antonie Van Leeuwenhoek 73:331. 1998. (2) S. Nelson. Rust of Lemongrass. Univ. Hawaii PD-57, 2008. (3) USDA, ARS, GRIN Online Database. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?12797 , accessed 25 April 2013. (4) R. Vilgalys and M. Hester. J Bacteriol. 172:4238, 1990.

scholarly journals Pseudomonas syringaeIncreases Water Availability in Leaf Microenvironments via Production of Hygroscopic Syringafactin

2019 ◽  
Author(s):  
Monica N. Hernandez ◽  
Steven E. Lindow
Keyword(s):  
Water Stress ◽  
Pseudomonas Syringae ◽  
Liquid Water ◽  
Water Availability ◽  
Bacterial Species ◽  
Habitat Modification ◽  
Wild Type ◽  
Gfp Fluorescence ◽  
Leaf Surfaces ◽  
Leaf Apoplast

ABSTRACTThe epiphytic bacteriumPseudomonas syringaestrain B728a produces the biosurfactant syringafactin which is hygroscopic. The water absorbing potential of syringafactin is high. At high relative humidities, syringafactin attracts 250% of its weight in water but is less hygroscopic at lower relative humidities. This suggests that syringafactin’s benefit to the producing cells is strongly context-dependent. The contribution of syringafactin to the water availability around cells on different matrices was assessed by examining water availability biosensor strains that expressgfpvia the water-stress activatedproUpromoter. Wild-type cells exhibited significantly less GFP fluorescence than a syringafactin-deficient strain, on humid but dry filters as well as on leaf surfaces indicating higher water availability. When infiltrated into the leaf apoplast, wild-type cells also subsequently exhibited less GFP fluorescence than a syringafactin-deficient strain. These results suggest that the apoplast is a dry, but humid environment and that, just as on dry but humid leaf surfaces, syringafactin increases liquid water availability and reduces the water stress experienced byP. syringae.IMPORTANCEMany microorganisms, including the plant pathogenPseudomonas syringae, produce amphiphilic compounds known as biosurfactants. While biosurfactants are known to disperse hydrophobic compounds and reduce water tension, they have other properties that can benefit the cells that produce them. Leaf colonizing bacteria experience frequent water stress since liquid water is only transiently present on or in leaf sites that they colonize. The demonstration that syringafactin, a biosurfactant produced byP. syringae, is sufficiently hygroscopic to increase water availability to cells, thus relieving water stress, reveals thatP. syringaecan modify its local habitat both on leaf surfaces and in the leaf apoplast. Such habitat modification may be a common role for biosurfactants produced by other bacterial species that colonize habitats that are not always water saturated such as soil.

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