scholarly journals Plant-like hooked miniature machines for on-leaf sensing and delivery

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Isabella Fiorello ◽  
Fabian Meder ◽  
Alessio Mondini ◽  
Edoardo Sinibaldi ◽  
Carlo Filippeschi ◽  
...  
Keyword(s):  
Agricultural Fields ◽  
Proof Of Concept ◽  
Plant Organs ◽  
Environmental Challenges ◽  
Vascular Tissues ◽  
Galium Aparine ◽  
Molecular Delivery ◽  
Leaf Surfaces ◽  
Strong Shear ◽  
Leaf Tissues

AbstractNew sustainable strategies for preserving plants are crucial for tackling environmental challenges. Bioinspired soft and miniature machines have the potential to operate in forests and agricultural fields by adapting their morphology to plant organs like leaves. However, applications on leaf surfaces are limited due to the fragility and heterogeneity of leaves, and harsh outdoor conditions. Here, we exploit the strong shear-dependent leaf-attachment of the hook-climber Galium aparine to create miniature systems that enable precision anchoring to leaf tissues via multifunctional microhooks. We first study the anchoring forces of the microhooks and then fabricate a soft wireless multiparameter sensor to monitor the leaf proximity and degradable hooks for in-plant molecular delivery to the vascular tissues of the leaves. In addition, we use a soft robotic proof-of-concept demonstrator to highlight how our hooks enable ratchet-like motion on leaves. This research showcases opportunities for specifically designing multifunctional machines for targeted applications in plant ecosystems.

scholarly journals Always on the bright side: the climbing mechanism of Galium aparine

2010 ◽  
Vol 278 (1715) ◽  
pp. 2233-2239 ◽  
Author(s):  
Georg Bauer ◽  
Marie-Christin Klein ◽  
Stanislav N. Gorb ◽  
Thomas Speck ◽  
Dagmar Voigt ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Host Plants ◽  
Turgor Pressure ◽  
Orientation Distribution ◽  
Galium Aparine ◽  
Climbing Plant ◽  
Single Leaf ◽  
Leaf Surfaces ◽  
Leaf Tissues ◽  
Strong Attachment

Galium aparine is a herbaceous climbing plant that attaches to host plants mainly via its leaves, which are covered by hooked trichomes. Although such hooks are found on both leaf surfaces, the leaves of G. aparine are mainly positioned upon the leaves of supporting plants and rarely beneath. In order to understand the mechanism underlying this observation, we have studied structural and mechanical properties of single leaf hooks, frictional properties of leaf surfaces, turgor pressure in different leaf tissues and bending properties of the leaves in different directions. Abaxial and adaxial leaf hooks differ significantly in orientation, distribution, structure and mechanical properties. In accordance with these differences, friction properties of leaves depend on the direction of the applied force and differ significantly between both leaf surfaces. This results in a ratchet mechanism. Abaxial leaf hooks provide strong attachment upon the leaves of adjacent plants, whereas adaxial hooks cause a gliding-off from the underside of the leaves of host plants. Thus, the leaves of G. aparine can function as attachment organs, and simultaneously orient themselves advantageously for their photosynthetic function. Further adaptations in turgor pressure or concerning an anisotropy of the flexural stiffness of the leaves have not been found.

scholarly journals First Report of Downy Mildew Caused by Pseudoperonospora cubensis on Chayote (Sechium edule) in Taiwan

Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1706-1706 ◽  
Author(s):  
Y. Ko ◽  
C. Y. Chen ◽  
C. W. Liu ◽  
S. S. Chen ◽  
S. Maruthasalam ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Plant Diseases ◽  
Pseudoperonospora Cubensis ◽  
First Report ◽  
Agricultural Improvement ◽  
Republic Of China ◽  
Sechium Edule ◽  
Leaf Surfaces ◽  
Leaf Tissues ◽  
The Republic

Chayote (Sechium edule) is cultivated on more than 500 ha in Taiwan for its edible shoots and fruit. In August 2005 and later, 40 to 75% of the chayote plants cultivated in the Taichung District Agricultural Improvement Station in Puli developed pale yellow, irregular spots on the upper leaf surfaces with corresponding sporulation on the lower leaf surfaces. The lesions eventually became necrotic and spread over the entire leaf surface, leading to defoliation. Pseudoperonospora cubensis, which was previously reported as the cause of downy mildew on squash (Cucurbita moschata), muskmelon (Cucumis melo), cucumber (Cucumis sativus), and sponge gourd (Luffa cylindrica) in Taiwan, was identified (1). Sporangiophores were 182 to 410 μm long, 4.8 to 7.2 μm wide, and dichotomously branched. Sporangia were grayish, ovoid to ellipsoidal, 18.2 to 38.6 μm long, and 13.5 to 25.2 μm wide. Biflagellate zoospores were 9.5 to 12.6 μm in diameter. Pathogenicity tests were conducted four times with six 2-week-old plants in each trial. A sporangial suspension (1 × 105 spores per ml) prepared from infected leaves (5 to 6 weeks after infection) was sprayed on all leaves until runoff. The plants were then covered with polythene bags and incubated for 48 h at 18 ± 1°C in a growth chamber. Control plants were sprayed with sterile water. Characteristic symptoms developed on all inoculated plants after 20 days, while control plants remained symptomless. Microscopic observation of leaf tissues of symptomatic plants confirmed the presence of P. cubensis. To our knowledge, this is the first report of P. cubensis causing downy mildew on chayote in Taiwan. References: (1) S. T. Hsu et al. List of Plant Diseases in Taiwan. The Phytopathological Society of the Republic of China, 2002.

Improvement of Hydrophobic Property of Stainless-Steel Plates by Forming Lens-Like Protrusions Similar to Oxalis Leaf Surfaces

2019 ◽  
Vol 813 ◽  
pp. 19-24
Author(s):  
Toshiyuki Horiuchi ◽  
Yoshie Imon ◽  
Kazuya Sumimoto ◽  
Akira Yanagida ◽  
Hiroshi Kobayashi
Keyword(s):  
Stainless Steel ◽  
Contact Angles ◽  
Steel Plates ◽  
Hydrophobic Property ◽  
Hydrophobic Properties ◽  
Leaf Surfaces ◽  
Leaf Tissues ◽  
Wet Chemical ◽  
Lotus Leaves ◽  
Wet Chemical Etching

Leaves of an obscure plant “oxalis deppei” are so hydrophobic that showered water droplets are almost completely repelled and hardly remained on their surfaces. For this reason, surface configurations were investigated. On the live leaves, there formed protrusions somewhat similar to those observed on lotus leaves which are well known as super hydrophobic leaves. However, in winter, it was found that even dead leaves were hydrophobic also. Because leaf tissues were shriveled and dried half, heights of protrusions with sizes of 20-50 μm were low, and undulations of surfaces were gentle and smooth, and pitches of undulations were as large as 30-70 μm. It was thought that such gentle lens-like protrusions would be probably formed on versatile stainless-steel plates using lithography and wet chemical etching. For this reason, arrays of protrusions with a size of 20 μm, a pitch of 35 μm, and heights of 6-7 μm were formed, and change of hydrophobic properties were investigated. As a result, the hydrophobic properties were effectively improved by forming even such gentle and smooth protrusions. It was also clarified that contact angles were improved almost in proportion to etched depths.

scholarly journals Pathogenicity of a Novel Biotype of Limonomyces roseipellis in Tall Fescue

Plant Disease ◽  
2003 ◽  
Vol 87 (9) ◽  
pp. 1031-1036 ◽  
Author(s):  
L. L. Burpee ◽  
C. W. Mims ◽  
L. P. Tredway ◽  
J. Bae ◽  
G. Jung
Keyword(s):  
Dna Sequences ◽  
Tall Fescue ◽  
Leaf Surface ◽  
Controlled Environment ◽  
Binucleate Cells ◽  
Foliar Blight ◽  
Abaxial Leaf Surface ◽  
Leaf Surfaces ◽  
Leaf Tissues ◽  
Papilla Formation

An unusual and undescribed foliar blight of tall fescue was observed in a home lawn and in turf grass research plots near Griffin, GA in May and June, 2000 and 2001. Isolation from lesions yielded mycelium of a basidiomycete with hyphal characteristics (binucleate cells, absence of clamp connections) associated with Laetisaria and Limonomyces spp. Isolates from blighted tall fescue and an isolate of Limonomyces roseipellis formed a clade distinct from isolates of Laetisaria fuciformis based on ribosomal DNA sequences. These data, in conjunction with cultural morphology, indicate that the basidiomycete from tall fescue represents a biotype of Limonomyces roseipellis that lacks clamp connections. In a controlled environment, isolates of the biotype induced foliar blight in the fescue cvs. Kentucky 31 and Rebel III. Histological observations revealed that the fungus colonized leaf surfaces as branched hyphae and aggregated hyphal strands. Penetration occurred via stomatal pores on the abaxial leaf surface. Colonization of leaf tissues was inter- and intracellular, with no evidence of papilla formation in response to invading hyphae. The name “cream leaf blight” is proposed for this new disease of tall fescue.

scholarly journals Droplet deposition during spray and leaf pH in aquatic weed control

2005 ◽  
Vol 62 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Neumárcio Vilanova da Costa ◽  
Dagoberto Martins ◽  
Roberto Antonio Rodella ◽  
Lívia Duarte Neves de Camargo da Costa
Keyword(s):  
Leaf Surface ◽  
Great Influence ◽  
Morphological Diversity ◽  
Aquatic Weed ◽  
Aquatic Weeds ◽  
Surface Wetting ◽  
Surface Tension Reduction ◽  
Leaf Surfaces ◽  
Leaf Tissues ◽  
The Mean

The morphological diversity of leaf surface and structures such as trichomes, stomata, cuticle, and waxes that exists among plant species can have great influence on the adherence and deposition of spray droplets, as well as on herbicide absorption. The aim of this research was to study leaf pH and to evaluate wetting areas after applications of solution surfactants on the following aquatic weeds: Enhydra anagallis, Eichhornia crassipes, Heteranthera reniformis, and Typha subulata. The aquatic weeds were grown in reservoirs containing water under open air conditions and their leaf tissues were collected when the plants reached full development (before flowering). The mean leaf pH varied between 5.50 and 7.50; E. anagallis should be pointed out for presenting the highest pH values, of 6.68 and 7.02 on the upper and lower leaf surfaces, respectively. Surface tension reduction for glyphosate alone (5.0% v v-1), glyphosate + Aterbane BR (5.0% + 0.5% v v-1), glyphosate + Silwet L-77 (5.0% + 0.05% v v-1), and surfactants alone, Aterbane BR (0.5% v v-1), and Silwet L-77 (0.05% v v-1), were, respectively: 72.1; 28.7; 23.3; 37.3, and 22.1 mN m-1.T. subulata was the aquatic species with the highest upper and lower leaf surface wetting area.

scholarly journals First Report of Erysiphe sedi on Sedum spectabile in North America

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1207-1207 ◽  
Author(s):  
L. Kiss ◽  
Margery L. Daughtrey
Keyword(s):  
New York ◽  
North America ◽  
Powdery Mildew ◽  
Market Value ◽  
First Report ◽  
Potted Plants ◽  
Powdery Mildews ◽  
Leaf Surfaces ◽  
Detached Leaves ◽  
Leaf Tissues

Since 1997, powdery mildew infections have been repeatedly observed on Sedum spectabile plants, cv. Autumn Joy, grown as ornamentals in commercial greenhouses in New York. Circular patches of gray mycelia appeared and spread on upper and occasionally on lower leaf surfaces followed by necrosis of the leaf tissues and defoliation. The new disease reduced the market value of the infected ornamentals and required chemical control. The pathogen produced conidia singly on 2- to 3-celled conidiophores occurring on the ectophytic hyphae. Conidia were subcylindrical, measured 27 to 36 μm × 13 to 17 μm, and contained no fibrosin bodies. Germinating conidia produced a short germ tube, 5 to 30 μm, terminating in a lobed appressorium. Hyphal appressoria were lobed to multi-lobed, opposite or spread along the hyphae. Cleistothecia were not found. Based on conidial characteristics, the pathogen was identified as Erysiphe sedi Braun. To confirm pathogenicity, potted healthy S. spectabile plants were placed near infected plants in the greenhouse. In addition, detached S. spectabile leaves were inoculated with the pathogen by touching them to powdery mildew colonies and then placed in plates filled with one layer of polystyrene balls floated in water. Plates were covered and kept in the laboratory. Uninfected potted plants kept in another greenhouse and noninoculated detached leaves served as controls. After 1 week, powdery mildew appeared on all infected plants and leaves exposed to or inoculated with the pathogen. The pathogen was morphologically identical to the original fungus. No symptoms were observed on the controls. E. sedi is a common Asiatic powdery mildew species infecting many crassulaceous plants (1,2) and was introduced to Eastern Europe from Asia (2). To our knowledge, this is the first report of E. sedi in North America. References: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987. (2) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fisher Verlag, Jena, 1995.

Preparation of luminescent titania/dye hybrid nanoparticles and their dissolution properties for controlling cellular environments

RSC Advances ◽  
2015 ◽  
Vol 5 (126) ◽  
pp. 104343-104353 ◽  
Author(s):  
K. Shiba ◽  
M. Tagaya ◽  
T. Sugiyama ◽  
N. Hanagata
Keyword(s):  
Delivery System ◽  
Fluorescein Isothiocyanate ◽  
Hybrid Nanoparticles ◽  
Proof Of Concept ◽  
Molecular Delivery ◽  
Dissolution Properties

Monodispersed titania/octadecylamine/fluorescein-isothiocyanate hybrid nanoparticles are synthesized to demonstrate a proof-of-concept for nanomedicines: an indirect molecular delivery system with no cytotoxicity.

Some Effects of Oxidant Air Pollutants (Ozone and Peroxyacetyl Nitrate) on the Ultrastructure of Leaf Tissues

1972 ◽  
Vol 30 ◽  
pp. 360-361
Author(s):  
William W. Thomson ◽  
Elizabeth S. Swanson
Keyword(s):  
Air Pollutants ◽  
Electron Microscopic Examination ◽  
Peroxyacetyl Nitrate ◽  
Electron Microscopic ◽  
Growth Physiology ◽  
Physiology And Biochemistry ◽  
Entire Plant ◽  
Leaf Tissues ◽  
Gaseous Hydrocarbons ◽  
The Individual

The oxidant air pollutants, ozone and peroxyacetyl nitrate, are produced in the atmosphere through the interaction of light with nitrogen oxides and gaseous hydrocarbons. These oxidants are phytotoxicants and are known to deleteriously affect plant growth, physiology, and biochemistry. In many instances they induce changes which lead to the death of cells, tissues, organs, and frequently the entire plant. The most obvious damage and biochemical changes are generally observed with leaves.Electron microscopic examination of leaves from bean (Phaseolus vulgaris L.) tobacco (Nicotiana tabacum L.) and cotton (Gossipyum hirsutum L.) fumigated for .5 to 2 hours with 0.3 -1 ppm of the individual oxidants revealed that changes in the ultrastructure of the cells occurred in a sequential fashion with time following the fumigation period. Although occasional cells showed severe damage immediately after fumigation, the most obvious change was an enhanced clarity of the cell membranes.

Direct measurement of electron-diffraction-pattern intensities using an energy loss spectrometer

1989 ◽  
Vol 47 ◽  
pp. 668-669
Author(s):  
A. G. Jackson ◽  
M. Rowe
Keyword(s):  
Thermal Effects ◽  
Dynamic Range ◽  
Scattering Amplitude ◽  
Dynamical Theory ◽  
Site Symmetry ◽  
Proof Of Concept ◽  
Parallel Acquisition ◽  
Kinematic Approximation ◽  
Speed Up ◽  
Structure Calculations

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.

Portein-gold labelling of ultrathin sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 680-681
Author(s):  
K. S. Zaychuk ◽  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Osmium Tetroxide ◽  
Rnase A ◽  
Leaf Ultrastructure ◽  
Double Membrane ◽  
Young Root ◽  
Leaf Tissues ◽  
Membrane Bound ◽  
Ultrathin Sections ◽  
Gold Labelling ◽  
Electron Dense Core

Wheat spot mosaic (WSpM), which frequently occurs with wheat streak mosaic virus was first reported in 1956 from Alberta. Singly isolated, WSpM causes chlorotic spots, chlorosis, stunting, and sometimes death of the wheat plants. The vector responsible for transmission is the eriophyid mite, Eriophyes tulipae Kiefer. The examination of leaf ultrastructure by electron microscopy has revealed double membrane bound bodies (DMBB’s) 0.1-0.2 μm in diameter. Dispersed fibrils within these bodies suggested the presence of nucleic acid. However, neither ribosomes characteristic of bacteria, mycoplasma and the psittacosis group of organisms nor an electron dense core characteristic of many viruses was commonly evident.In an attempt to determine if the DMBB’s contain nucleic acids, RNase A, DNase I, and lactoferrin protein were conjugated with 10 nm colloidal gold as previously described. Young root and leaf tissues from WSpM-affected wheat plants were fixed in glutaraldehyde, postfixed in osmium tetroxide,and embedded in Spurr’s resin.

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