Chapter Four: Life Cycles in Major Lineages of Photosynthetic Eukaryotes, with a Special Reference to the Origin of Land Plants

2008 ◽  
Vol 47 (1) ◽  
pp. 17 ◽  
Author(s):  
Hilary A. McManus ◽  
Yin-Long Qiu
Keyword(s):  
Special Reference ◽  
Life Cycles ◽  
Land Plants ◽  
Photosynthetic Eukaryotes

scholarly journals Notes on Early Land Plants Today. 62. A synopsis of Myriocoleopsis (Lejeuneaceae, Marchantiophyta) with special reference to transfer of Cololejeunea minutissima to Myriocoleopsis 

Phytotaxa ◽  
2014 ◽  
Vol 183 (4) ◽  
pp. 293 ◽  
Author(s):  
YING YU ◽  
TAMÁS PÓCS ◽  
RUI-LIANG ZHU
Keyword(s):  
Special Reference ◽  
Land Plants ◽  
Leaf Margin ◽  
Oil Bodies ◽  
Large Size ◽  
Early Land ◽  
Stem Structure

The segregate of Myriocoleopsis was firstly proposed by Schiffner (1944: 234) based on some remarkable characters, such as dimorphic stems, long male spikes, erect leafy axes arising from a creeping stolon and reduced lobules (Gradstein & Vital 1975; Reiner-Drehwald & Gradstein 1995). Hitherto a total of three species are recognized in this genus: Myriocoleopsis fluviatilis (Stephani 1895: 248) Reiner & Gradstein (1997: 639) known from Argentina, Brazil and Ecuador (Reiner-Drehwald & Gradstein 1997; Gradstein & da Costa 2003), M. gymnocolea Spruce (1884: 296) Reiner & Gradstein (1997: 640) known only from Brazil (Reiner-Drehwald & Gradstein 1997) and M. vuquangensis (Pócs & Ninh 2005: 156) Pócs (2010: 124) known only from Vietnam (Pócs 2010). Myriocoleopsis shares substantial resemblance with Cololejeunea (Spruce 1884: 291) Stephani (1891: 208) (particular subgen. Protocolea Schuster (1963: 171)) in the stem structure, absence of underleaves, lobular form, leaf margin, oil bodies and sporophytes (Gradstein & Vital 1975; Schuster 1980; Reiner-Drehwald & Gradstein 1995). Although the rigid stem and large size of Myriocoleopsis was also found in some rheophytic taxa of Cololejeunea such as subgen. Chlorolejeunea Benedix (1953: 81), it had been interpreted as adaption to similar habitats (Reiner-Drehwald & Gradstein 1995).

scholarly journals The World of Algae Reveals a Broad Variety of Cryptochrome Properties and Functions

2021 ◽  
Vol 12 ◽  
Author(s):  
Jan Petersen ◽  
Anxhela Rredhi ◽  
Julie Szyttenholm ◽  
Sabine Oldemeyer ◽  
Tilman Kottke ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Algal Cell ◽  
Algal Species ◽  
Life Cycles ◽  
Land Plants ◽  
Abiotic Factor ◽  
Secondary Endosymbiosis ◽  
Biological Clocks ◽  
Terrestrial Habitats ◽  
Broad Variety

Algae are photosynthetic eukaryotic (micro-)organisms, lacking roots, leaves, and other organs that are typical for land plants. They live in freshwater, marine, or terrestrial habitats. Together with the cyanobacteria they contribute to about half of global carbon fixation. As primary producers, they are at the basis of many food webs and they are involved in biogeochemical processes. Algae are evolutionarily distinct and are derived either by primary (e.g., green and red algae) or secondary endosymbiosis (e.g., diatoms, dinoflagellates, and brown algae). Light is a key abiotic factor needed to maintain the fitness of algae as it delivers energy for photosynthesis, regulates algal cell- and life cycles, and entrains their biological clocks. However, excess light can also be harmful, especially in the ultraviolet range. Among the variety of receptors perceiving light information, the cryptochromes originally evolved as UV-A and blue-light receptors and have been found in all studied algal genomes so far. Yet, the classification, biophysical properties, wavelength range of absorbance, and biological functions of cryptochromes are remarkably diverse among algal species, especially when compared to cryptochromes from land plants or animals.

scholarly journals Phylogenomics Provides New Insights into Gains and Losses of Selenoproteins among Archaeplastida

2019 ◽  
Vol 20 (12) ◽  
pp. 3020 ◽  
Author(s):  
Hongping Liang ◽  
Tong Wei ◽  
Yan Xu ◽  
Linzhou Li ◽  
Sunil Kumar Sahu ◽  
...  
Keyword(s):  
Horizontal Gene Transfer ◽  
Evolutionary Dynamics ◽  
Viral Infections ◽  
Land Plants ◽  
Acidic Environment ◽  
Transcriptome Data ◽  
Photosynthetic Eukaryotes ◽  
Redox Active ◽  
Genomic Search ◽  
Gains And Losses

Selenoproteins that contain selenocysteine (Sec) are found in all kingdoms of life. Although they constitute a small proportion of the proteome, selenoproteins play essential roles in many organisms. In photosynthetic eukaryotes, selenoproteins have been found in algae but are missing in land plants (embryophytes). In this study, we explored the evolutionary dynamics of Sec incorporation by conveying a genomic search for the Sec machinery and selenoproteins across Archaeplastida. We identified a complete Sec machinery and variable sizes of selenoproteomes in the main algal lineages. However, the entire Sec machinery was missing in the Bangiophyceae-Florideophyceae clade (BV) of Rhodoplantae (red algae) and only partial machinery was found in three species of Archaeplastida, indicating parallel loss of Sec incorporation in different groups of algae. Further analysis of genome and transcriptome data suggests that all major lineages of streptophyte algae display a complete Sec machinery, although the number of selenoproteins is low in this group, especially in subaerial taxa. We conclude that selenoproteins tend to be lost in Archaeplastida upon adaptation to a subaerial or acidic environment. The high number of redox-active selenoproteins found in some bloom-forming marine microalgae may be related to defense against viral infections. Some of the selenoproteins in these organisms may have been gained by horizontal gene transfer from bacteria.

Posture control in land plants: growth, position sensing, proprioception, balance, and elasticity

2019 ◽  
Vol 70 (14) ◽  
pp. 3467-3494 ◽  
Author(s):  
Bruno Moulia ◽  
Renaud Bastien ◽  
Hugo Chauvet-Thiry ◽  
Nathalie Leblanc-Fournier
Keyword(s):  
Life Cycles ◽  
Posture Control ◽  
Land Plants ◽  
Active Motion ◽  
Position Sensing ◽  
Whole Plant ◽  
Evolutionary Step ◽  
Asymmetric Growth ◽  
Plant Level ◽  
And Control

Abstract The colonization of the atmosphere by land plants was a major evolutionary step. The mechanisms that allow for vertical growth through air and the establishment and control of a stable erect habit are just starting to be understood. A key mechanism was found to be continuous posture control to counterbalance the mechanical and developmental challenges of maintaining a growing upright structure. An interdisciplinary systems biology approach was invaluable in understanding the underlying principles and in designing pertinent experiments. Since this discovery previously held views of gravitropic perception had to be reexamined and this has led to the description of proprioception in plants. In this review, we take a purposefully pedagogical approach to present the dynamics involved from the cellular to whole-plant level. We show how the textbook model of how plants sense gravitational force has been replaced by a model of position sensing, a clinometer mechanism that involves both passive avalanches and active motion of statoliths, granular starch-filled plastids, in statocytes. Moreover, there is a transmission of information between statocytes and other specialized cells that sense the degree of organ curvature and reset asymmetric growth to straighten and realign the structure. We give an overview of how plants have used the interplay of active posture control and elastic sagging to generate a whole range of spatial displays during their life cycles. Finally, a position-integrating mechanism has been discovered that prevents directional plant growth from being disrupted by wind-induced oscillations.

scholarly journals Multigene Phylogeny of Land Plants with Special Reference to Bryophytes and the Earliest Land Plants

2000 ◽  
Vol 17 (12) ◽  
pp. 1885-1895 ◽  
Author(s):  
Daniel L. Nickrent ◽  
Christopher L. Parkinson ◽  
Jeffrey D. Palmer ◽  
R. Joel Duff
Keyword(s):  
Special Reference ◽  
Land Plants ◽  
Multigene Phylogeny

scholarly journals Embryophyte stress signaling evolved in the algal progenitors of land plants

2018 ◽  
Vol 115 (15) ◽  
pp. E3471-E3480 ◽  
Author(s):  
Jan de Vries ◽  
Bruce A. Curtis ◽  
Sven B. Gould ◽  
John M. Archibald
Keyword(s):  
Expression Patterns ◽  
Light Stress ◽  
Global Gene Expression ◽  
Growth Conditions ◽  
Global Scale ◽  
Land Plant ◽  
High Irradiance ◽  
Land Plants ◽  
Photosynthetic Eukaryotes ◽  
Terrestrial Life

Streptophytes are unique among photosynthetic eukaryotes in having conquered land. As the ancestors of land plants, streptophyte algae are hypothesized to have possessed exaptations to the environmental stressors encountered during the transition to terrestrial life. Many of these stressors, including high irradiance and drought, are linked to plastid biology. We have investigated global gene expression patterns across all six major streptophyte algal lineages, analyzing a total of around 46,000 genes assembled from a little more than 1.64 billion sequence reads from six organisms under three growth conditions. Our results show that streptophyte algae respond to cold and high light stress via expression of hallmark genes used by land plants (embryophytes) during stress–response signaling and downstream responses. Among the strongest differentially regulated genes were those associated with plastid biology. We observed that among streptophyte algae, those most closely related to land plants, especially Zygnema, invest the largest fraction of their transcriptional budget in plastid-targeted proteins and possess an array of land plant-type plastid-nucleus communication genes. Streptophyte algae more closely related to land plants also appear most similar to land plants in their capacity to respond to plastid stressors. Support for this notion comes from the detection of a canonical abscisic acid receptor of the PYRABACTIN RESISTANCE (PYR/PYL/RCAR) family in Zygnema, the first found outside the land plant lineage. We conclude that a fine-tuned response toward terrestrial plastid stressors was among the exaptations that allowed streptophytes to colonize the terrestrial habitat on a global scale.

scholarly journals Phylogenomics provides new insights into gains and losses of selenoproteins among Archaeplastida

2019 ◽  
Author(s):  
Hongping Liang ◽  
Tong Wei ◽  
Yan Xu ◽  
Linzhou Li ◽  
Sunil Kumar Sahu ◽  
...  
Keyword(s):  
Horizontal Gene Transfer ◽  
Evolutionary Dynamics ◽  
Viral Infections ◽  
Land Plants ◽  
Acidic Environment ◽  
Transcriptome Data ◽  
Photosynthetic Eukaryotes ◽  
Redox Active ◽  
Genomic Search ◽  
Gains And Losses

AbstractSelenoproteins that contain selenocysteine (Sec) are found in all kingdoms of life. Although they constitute a small proportion of the proteome, selenoproteins play essential roles in many organisms. In photosynthetic eukaryotes, selenoproteins have been found in algae but are missing in land plants (embryophytes). In this study, we explored the evolutionary dynamics of Sec incorporation by conveying a genomic search for the Sec machinery and selenoproteins across Archaeplastida. We identified a complete Sec machinery and variable sizes of selenoproteomes in the main algal lineages. However, the entire Sec machinery was missing in the BV clade (Bangiophyceae-Florideophyceae) of Rhodoplantae (red algae) and only partial machinery was found in three species of Archaeplastida, indicating parallel loss of Sec incorporation in different groups of algae. Further analysis of genome and transcriptome data suggests that all major lineages of streptophyte algae display a complete Sec machinery, although the number of selenoproteins is low in this group, especially in subaerial taxa. We conclude that selenoproteins tend to be lost in Archaeplastida upon adaptation to a subaerial or acidic environment. The high number of redox-active selenoproteins found in some bloom-forming marine microalgae may be related to defense against viral infections. Some of the selenoproteins in these organisms may have been gained by horizontal gene transfer from bacteria.

scholarly journals Gamete expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Tom Dierschke ◽  
Eduardo Flores-Sandoval ◽  
Madlen I Rast-Somssich ◽  
Felix Althoff ◽  
Sabine Zachgo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Life Cycles ◽  
Land Plants ◽  
Marchantia Polymorpha ◽  
Loss Of Function ◽  
Unicellular Eukaryotes ◽  
Tale Homeodomain ◽  
Embryonic Arrest ◽  
Sporophyte Development

Eukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in gametes primes the haploid-to-diploid transition. In the unicellular chlorophyte alga Chlamydomonas, KNOX and BELL TALE-homeodomain genes mediate this transition. We demonstrate that in the liverwort Marchantia polymorpha, paternal (sperm) expression of three of five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of both MpKNOX1 and MpBELL34 mediate the haploid-to-diploid transition. Loss-of-function alleles of MpKNOX1 result in zygotic arrest, whereas a loss of either maternal or paternal MpBELL234 results in variable zygotic and early embryonic arrest. Expression of MpKNOX1 and MpBELL34 during diploid sporophyte development is consistent with a later role for these genes in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.

Taxonomic Status of Calanus finmarchicus and C. glacialis (Copepoda), with Special Reference to Adult Males

1971 ◽  
Vol 28 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Bruce W. Frost
Keyword(s):  
Vertical Distribution ◽  
Special Reference ◽  
Geographical Distribution ◽  
Morphometric Analysis ◽  
Taxonomic Status ◽  
Life Cycles ◽  
Calanus Finmarchicus ◽  
Adult Males ◽  
Adult Females ◽  
Taxonomic Studies

A morphometric analysis using certain taxonomic characters of adult males of Calanus finmarchicus (Gunnerus) and C. glacialis Jaschnov shows that the taxa comprise two non-overlapping clusters. Calanus finmarchicus and C. glacialis are probably reproductively isolated. Differences between the species in geographical distribution, vertical distribution, and timing of life cycles also support this conclusion. Previous taxonomic studies of adult females of the two species have yielded inconclusive results, probably because the analyses were based largely on subgeneric characters.

scholarly journals Gamete-specific expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha

2020 ◽  
Author(s):  
Tom Dierschke ◽  
Eduardo Flores-Sandoval ◽  
Madlen I. Rast-Somssich ◽  
Felix Althoff ◽  
Sabine Zachgo ◽  
...  
Keyword(s):  
Life Cycles ◽  
Land Plants ◽  
Marchantia Polymorpha ◽  
Loss Of Function ◽  
Specific Expression ◽  
Unicellular Eukaryotes ◽  
Tale Homeodomain ◽  
Multicellular Organisms ◽  
Embryonic Arrest ◽  
Sporophyte Development

AbstractEukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in the two gametes directs the haploid-to-diploid transition. In the unicellular Chlorophyte alga Chlamydomonas KNOX and BELL TALE-homeodomain genes mediate the transition. Here we demonstrate that in the liverwort Marchantia polymorpha paternal (sperm) expression three of the five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of MpKNOX1 mediate the haploid-to-diploid transition. Loss-of-function alleles of either result in zygotic or early embryonic arrest. In land plants both the haploid gametophyte and diploid sporophyte are complex multicellular organisms. Expression of MpKNOX1 and two other paralogs, MpBELL1 and MpKNOX2, during sporophyte development is consistent with a later role in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.

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