Results 241 to 250 of about 99,408 (270)

Sieve Elements: The Favourite Habitat of Phytoplasmas

2018
The sieve elements are the only plant compartments, where phytoplasmas can survive and propagate. Therefore, this chapter is focussed on the specific molecular and cell-biological properties of the sieve element. Sieve element-companion cell complexes arise from (pro)cambial mother cells induced by key genes known to be decisive for sieve-element ...
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Sieve‐Element Characters of the Proteaceae and Elaeagnaceae: Nuclear Crystals, Phloem Proteins and Sieve‐Element Plastids

Botanica Acta, 1995
AbstractThe sieve‐element characters of 34 species from the Proteaceae and Elaeagnaceae have been studied by transmission electron microscopy. While nondispersive protein bodies and dispersive P‐protein are typical components of both families, specific forms and/or their distinctive origin accentuate some taxa.
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Microfilaments in pores between frozen-etched sieve elements

Planta, 1968
Sieve tubes were frozen before being cut from plants and were prepared for electron microscopy by freeze-etching. Structures that may be interpreted as filaments appeared in and near pores through sieve plates. Their presence suggests that filaments seen in sieve-pores prepared chemically may be there normally.
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Modeling the Hydraulic Conductivity of Phloem Sieve Elements

2019
Phloem transport of photoassimilates affects nearly all aspects of plant life, from growth to reproduction. This chapter summarizes mathematical techniques to quantify the impact of sieve element anatomy on phloem transport processes.
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Novel diffractive optical element: binary photon sieve

Optical Engineering, 2011
In this paper, we developed a novel photon sieve consisting of a large number of precisely positioned holes distributed according to an underlying Fresnel zone plate (FZP) geometry, while the holes at transparent and opaque circular rings of the FZP have a π phase shift.
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Proteomics of isolated sieve tubes fromNicotiana tabacum: sieve element–specific proteins reveal differentiation of the endomembrane system

Proceedings of the National Academy of Sciences of the United States of America, 2022
Viktoriya Vasina, Max Kraner, Winfried S Peters   +2 more
exaly  

Regeneration and Differentiation of Sieve Tube Elements

1970
Publisher Summary This chapter discusses regeneration and differentiation of sieve tube elements. The pattern of first differentiation of sieve tubes in the young leaf is continuous and acropetal. The first sieve tube element in the leaf forms at a separate locus on the outer side of the procambial strand near the base of the leaf.
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Sieve Elements in Haustoria of Parasitic Angiosperms

1990
The necessity for conducting elements within haustoria of phanerogamic parasites is obvious, especially since holoparasitic angiosperms lack roots and assimilatory organs. Water as well as organic substances must be taken up, therefore, by specialized haustoria (Kuijt 1969; Kollmann and Dorr 1987). The faster the parasite grows, the more efficient must
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Sieve Elements; Extraxylary Mechanical Tissue

2023
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Sieve Element Structure in Relation to Function

1975
Translocation in the phloem of higher plants represents a complex physiological process with several partial reactions working together. Uptake and release of substances, energy transfer as well as storage of assimilates, are involved; or there may be a requirement in some cases for the mechanism of long-distance transport.
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