The Experts below are selected from a list of 1698 Experts worldwide ranked by ideXlab platform
J H Hill - One of the best experts on this subject based on the ideXlab platform.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
Jan Rohozinski - One of the best experts on this subject based on the ideXlab platform.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
A H Epstein - One of the best experts on this subject based on the ideXlab platform.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
-
probable mechanical transmission of a virus like agent from rose rosette disease infected multiflora rose to nicotiana species
Annals of Applied Biology, 2001Co-Authors: Jan Rohozinski, A H Epstein, J H HillAbstract:Summary As part of efforts to identify the causal agent of the rose rosette disease (RRD) of multiflora rose (Rosa multiflora Thunb.), root tip extracts from both symptomatic and nonsymptomatic roses were used to mechanically inoculate leaves of Nicotiana glutinosa. Pale green spots were observed along the margins of the major leaf veins only on leaves inoculated with extracts prepared from symptomatic rose plants. Light microscopy revealed abnormal development of the palisade and Spongy Mesophyll cells in the symptomatic tissue, although no virus-like particles (VLPs) were observed by electron microscopy. However, VLPs were observed in cells from tissue adjacent to the leaf veins and bordered by the pale green spots. Inoculation of N. benthamiana with extracts from symptomatic N. glutinosa initially did not result in visible symptoms on N. benthamiana inoculated leaves. However, approximately 4 wk post inoculation, splitting of leaf tissue across and along major leaf veins in expanding leaves occurred. In later stages of leaf expansion some leaves split in regions not associated with veins. Light microscopy of thick sections revealed separation between palisade cells and groups of small dead cells in the Mesophyll tissue of expanding systemically infected leaf blades. Electron microscopy revealed crystalline arrays in the cytoplasm of Mesophyll cells. No abnormal cellular changes were observed in plants inoculated with extracts prepared from nonsymptomatic rose plants.
Eustaquio Gilpelegrin - One of the best experts on this subject based on the ideXlab platform.
-
non contact ultrasonic resonant spectroscopy resolves the elastic properties of layered plant tissues
Applied Physics Letters, 2018Co-Authors: Tomas Gomez Alvarezarenas, Domingo Sanchoknapik, Jose Javier Pegueropina, A Gomezarroyo, Eustaquio GilpelegrinAbstract:This paper describes the application of the wide-band non-contact ultrasonic resonant spectroscopy technique to layered plant tissues (leaves), a method to extract the properties of main component tissues: palisade parenchyma and Spongy Mesophyll, a verification of the obtained properties, and a discussion of the implications of the observed elastic anisotropy. Transmission coefficient spectra of Ligustrum lucidum leaves with the thickness in the range of 250–850 μm revealing several order thickness resonances have been measured. A leaf acoustic model based on a two-layered structure and a metaheuristic (simulated annealing algorithm) is used to solve the inverse problem. The extracted parameters of these two layers of tissue are consistent with cross-sectional cryo-SEM images and other independent measurements. The extracted resonant frequency and the impedance of each layer explain the origin of the observed resonances. Finally, the elastic modulus of each layer is extracted and analyzed. The presented technique is a unique tool to study (in vivo and in a completely non-invasive way) the ultrasonic, elastic, and viscoelastic properties of layered plant tissues which could lead to a better understanding of the relationship between the tissue microstructure and the tissue function with macroscopic properties and how this may affect water relations.This paper describes the application of the wide-band non-contact ultrasonic resonant spectroscopy technique to layered plant tissues (leaves), a method to extract the properties of main component tissues: palisade parenchyma and Spongy Mesophyll, a verification of the obtained properties, and a discussion of the implications of the observed elastic anisotropy. Transmission coefficient spectra of Ligustrum lucidum leaves with the thickness in the range of 250–850 μm revealing several order thickness resonances have been measured. A leaf acoustic model based on a two-layered structure and a metaheuristic (simulated annealing algorithm) is used to solve the inverse problem. The extracted parameters of these two layers of tissue are consistent with cross-sectional cryo-SEM images and other independent measurements. The extracted resonant frequency and the impedance of each layer explain the origin of the observed resonances. Finally, the elastic modulus of each layer is extracted and analyzed. The presented ...
Biao Ding - One of the best experts on this subject based on the ideXlab platform.
-
Allelic RNA Motifs in Regulating Systemic Trafficking of Potato Spindle Tuber Viroid
MDPI AG, 2018Co-Authors: Ryuta Takeda, Neocles B Leontis, Craig L. Zirbel, Ying Wang, Biao DingAbstract:Intercellular RNA trafficking has been shown as a widely-existing phenomenon that has significant functions in many aspects of biology. Viroids, circular noncoding RNAs that cause plant diseases, have been a model to dissect the role of RNA structural motifs in regulating intercellular RNA trafficking in plants. Recent studies on potato spindle tuber viroid (PSTVd) showed that the RNA motif loop 19 is important for PSTVd to spread from palisade to Spongy Mesophyll in infected leaves. Here, we performed saturated mutational analysis to uncover all possible functional variants of loop 19 and exploit this data to pinpoint to a three-dimensional structural model of this motif. Interestingly, we found that two distinct structural motifs can replace loop 19 and retain the systemic trafficking capacity. One of the alternative structures rapidly emerged from the inoculation using a loop 19 abolished mutant that is not capable of systemic trafficking. Our observation indicates the flexibility of multiple structural arrangements interchangeably exerting similar function at a particular RNA locus. Taken together, this study deepens the understanding of RNA structural motifs-regulated viroid RNA trafficking, which has broad implications for studying RNA intercellular trafficking as well
-
a three dimensional rna motif in potato spindle tuber viroid mediates trafficking from palisade Mesophyll to Spongy Mesophyll in nicotiana benthamiana
The Plant Cell, 2011Co-Authors: Ryuta Takeda, Anton I Petrov, Neocles B Leontis, Biao DingAbstract:Cell-to-cell trafficking of RNA is an emerging biological principle that integrates systemic gene regulation, viral infection, antiviral response, and cell-to-cell communication. A key mechanistic question is how an RNA is specifically selected for trafficking from one type of cell into another type. Here, we report the identification of an RNA motif in Potato spindle tuber viroid (PSTVd) required for trafficking from palisade Mesophyll to Spongy Mesophyll in Nicotiana benthamiana leaves. This motif, called loop 6, has the sequence 5′-CGA-3′...5′-GAC-3′ flanked on both sides by cis Watson-Crick G/C and G/U wobble base pairs. We present a three-dimensional (3D) structural model of loop 6 that specifies all non-Watson-Crick base pair interactions, derived by isostericity-based sequence comparisons with 3D RNA motifs from the RNA x-ray crystal structure database. The model is supported by available chemical modification patterns, natural sequence conservation/variations in PSTVd isolates and related species, and functional characterization of all possible mutants for each of the loop 6 base pairs. Our findings and approaches have broad implications for studying the 3D RNA structural motifs mediating trafficking of diverse RNA species across specific cellular boundaries and for studying the structure-function relationships of RNA motifs in other biological processes.