Evolutionary history and stress regulation of the lectin superfamily in higher plants

Chromodomain-containing LTR retrotransposons are one of the most successful groups of mobile elements in plant genomes. Previously, we demonstrated that two types of chromodomains (CHDs) are carried by plant LTR retrotransposons. Chromodomains from group I (CHD_I) were detected only in Tcn1-like LTR retrotransposons from nonseed plants such as mosses (including the model moss species Physcomitrella) and lycophytes (the Selaginella species). LTR retrotransposon chromodomains from group II (CHD_II) have been described from a wide range of higher plants. In the present study, we performed computer-based mining of plant LTR retrotransposon CHDs from diverse plants with an emphasis on spike-moss Selaginella. Our extended comparative and phylogenetic analysis demonstrated that two types of CHDs are present only in the Selaginella genome, which puts this species in a unique position among plants. It appears that a transition from CHD_I to CHD_II and further diversification occurred in the evolutionary history of plant LTR retrotransposons at approximately 400 MYA and most probably was associated with the evolution of chromatin organization.

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Insect taxonomy in species-rich countries: the way forward?

Anais da Sociedade Entomológica do Brasil ◽

10.1590/s0301-80591998000100001 ◽

1998 ◽

Vol 27 (1) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Laurence A. Mound

Keyword(s):

Data Analysis ◽

Evolutionary History ◽

Biological Diversity ◽

Higher Plants ◽

Living Things ◽

History Of ◽

Living Species ◽

Natural Diversity ◽

Insect Taxonomy ◽

Rich Countries

There are two extremes in taxonomic behavior - publishing quickly as new taxa become available, and waiting a lifetime in the hope of publishing results that cannot be faulted. Neither of these extremes meets the needs of contemporary biologists in furthering our understanding of the evolution and maintenance of biological diversity. Part of the reason for these extremes is our failure to define suitable objectives for taxonomy. Instead of emphasising the units of biological diversity, we should concentrate on investigating patterns, structural, biological, ecological, temporal, and geographical, because it is these patterns that will generate novel ideas about the evolutionary history of organisms, and that will be most likely to be of interest to the future of our own species. To investigate these patterns, we need to give greater thought to ensuring that our methods of data acquisition are consistent with our methods of data analysis. Even if we take seriously as our objective the description of all living species, then we should be devising methods of sampling natural diversity that are statistically acceptable, not haphazard. However, the following comments, credited to Willis Jepson (1867-1946) in the latest edition of the Jepson Manual of Higher Plants of California, seem appropriate to our problems as insect taxonomists: "The botanist's objective is a furtherance of knowledge of living plants. He wishes to discover new facts and establish new principles. If wise, he will never try to produce a work which is perfect, complete and final. Any such work would be a paradox and at cross purposes with our knowledge of living things and our ideas of endless evolution associated with them. Completion, perfection, finality, represent an anomaly, a contradiction in the field of biology. The far seeing botanist will strive to do work which is inspiring, productive of thought and promoting the soundest progress, so that botanical science will ever advance into new and more fruitful fields".

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Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

Behavioral and Brain Sciences ◽

10.1017/s0140525x18000274 ◽

2018 ◽

Vol 41 ◽

Author(s):

Kevin Arceneaux

Keyword(s):

Decision Making ◽

Individual Differences ◽

Cognitive Processes ◽

Evolutionary History ◽

Behavioral Responses ◽

History Of ◽

Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083035 ◽

1978 ◽

Vol 36 (2) ◽

pp. 434-435

Author(s):

D. Reis ◽

B. Vian ◽

J. C. Roland

Keyword(s):

Cell Wall ◽

Self Assembly ◽

Plant Cell Wall ◽

Higher Plants ◽

Three Dimensional ◽

Cytochemical Study ◽

Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100094401 ◽

1972 ◽

Vol 30 ◽

pp. 230-231

Author(s):

James Cronshaw ◽

Jamison E. Gilder

Keyword(s):

Plasma Membrane ◽

Atpase Activity ◽

Adenosine Triphosphatase ◽

Higher Plants ◽

High Surface ◽

Root Tip ◽

Animal Cells ◽

Physiological Processes ◽

Tip Cells ◽

Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

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A Scanning Electron Microscopic Study of Pro-Vascular Cellular Morphology in Chaetophora Incressata

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119880 ◽

1985 ◽

Vol 43 ◽

pp. 638-639

Author(s):

A. E. Hotchkiss ◽

A. T. Hotchkiss ◽

R. P. Apkarian

Keyword(s):

Green Algae ◽

Vascular Plants ◽

Vascular System ◽

Higher Plants ◽

Wall Structure ◽

Electron Microscopic ◽

Physiological Processes ◽

Scanning Electron Microscopic Study ◽

Scanning Electron Microscopic ◽

Scanning Electron

Multicellular green algae may be an ancestral form of the vascular plants. These algae exhibit cell wall structure, chlorophyll pigmentation, and physiological processes similar to those of higher plants. The presence of a vascular system which provides water, minerals, and nutrients to remote tissues in higher plants was believed unnecessary for the algae. Among the green algae, the Chaetophorales are complex highly branched forms that might require some means of nutrient transport. The Chaetophorales do possess apical meristematic groups of cells that have growth orientations suggestive of stem and root positions. Branches of Chaetophora incressata were examined by the scanning electron microscope (SEM) for ultrastructural evidence of pro-vascular transport.

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