Thalli Of Marchantia Polymorpha Research Articles

A Comprehensive Toolkit for Quick and Easy Visualization of Marker Proteins, Protein-Protein Interactions and Cell Morphology in Marchantia polymorpha.

Even though stable genomic transformation of sporelings and thalli of Marchantia polymorpha is straightforward and efficient, numerous problems can arise during critical phases of the process such as efficient spore production, poor selection capacity of antibiotics or low transformation efficiency. It is therefore also desirable to establish quick methods not relying on stable transgenics to analyze the localization, interactions and functions of proteins of interest. The introduction of foreign DNA into living cells via biolistic mechanisms has been first reported roughly 30 years ago and has been commonly exploited in established plant model species such as Arabidopsis thaliana or Nicotiana benthamiana. Here, we report the fast and reliable transient biolistic transformation of Marchantia thallus epidermal cells using fluorescent protein fusions. We present a catalog of fluorescent markers which can be readily used for tagging of a variety of subcellular compartments. Moreover, we report the functionality of the bimolecular fluorescence complementation (BiFC) in M. polymorpha with the example of the p-body markers MpDCP1/2. Finally, we provide standard staining procedures for live cell imaging in M. polymorpha, applicable to visualize cell boundaries or cellular structures, to complement or support protein localizations and to understand how results gained by transient transformations can be embedded in cell architecture and dynamics. Taken together, we offer a set of easy and quick tools for experiments that aim at understanding subcellular localization, protein–protein interactions and thus functions of proteins of interest in the emerging early diverging land plant model M. polymorpha.

The Influence of Spermine and 6‐Benzylaminopurine on Putative Caspase Activity during Senescence inMarchantia polymorphaThalli

CaspACE fluoroisothiocyanate‐valyl‐alanyl‐aspartyl‐[d‐fluoromethylketone] in situ marker was used to identify putative caspase activity in senescing Marchantia polymorpha thalli. Fluorescence microscopy showed that this activity was localized in the lower parenchyma cells of untreated tissue. This putative caspase activity was significantly decreased in spermine‐ and 6‐benzylaminopurine‐treated tissue.

The Influence of Spermine on the Activity of a Protein Kinase C-like Enzyme in Marchantia polymorpha Thalli During Programmed Cell Death

Abstract Protein Kinase C-like activity was established in Marchantia polymorpha. Different concentrations were detected in young and old tissue extracts from untreated and spermine-treated thalli after agarose gel electrophoresis in the presence of a PKC-specific fluorescent tags. Cytosolic putative PKC concentrations (nmol/g tissue) in untreated young thalli were higher than concentrations in old tissue. Old spermine-treated tissue possessed higher cytosolic putative PKC concentrations than young untreated thalli. Both young and old spermine-treated tissue extracts possessed higher total protein levels than young and old untreated tissue extracts. The data suggest that spermine-treatment evoked a qualitative and quantitative decrease in senescence.

The Influence of Spermine on theIn SituExpression of a Protein Kinase Associated with Senescence inMarchantia polymorphaThalli

Fluorescein‐conjugated bisindolylmaleimide inhibitor (FIM‐1) was used to identify protein kinase C (PKC) presence and activity in Marchantia polymorpha thalli. Fluorescence microscopy showed that PKC activity occurred in the membranes of parenchymous and chloroplast‐containing cells. PKC activity increased with distance from the thallus apex in untreated tissue. Spermine‐treated tissue displayed significantly higher levels of PKC activity in comparison with untreated tissue, and PKC activity decreased with distance from the apex of the thallus.

The Influence of Ethylene and Spermine on Phosphatase Activity During Senescence in Marchantia polymorpha

Two isophosphatases were identified in senescing Marchantia polymorpha thalli. Ethylene elevated total phosphatase activity by 133%-155%. Spermine reduced total phosphatase activity by 135%-175%. Simultaneous treatment with ethylene and spermine led to a 120%-163% decrease in activity compared with ethylene treatment alone. The increase in phosphatase levels associated with ethylene treatment suggests that this enzyme is associated with senescence in Marchantia. An antisenescence function for spermine is also indicated.

SPECIFIC PHOTOREGULATION BY PHYTOCHROME OF EPINASTY and LIGHT‐INDUCED ETHYLENE PRODUCTION IN MARCHANTIA POLYMORPHA*

Abstract— A study is made of the influence of phytochrome on light‐induced ethylene production and epinasty in green Marchantia polymorpha thalli. Ethylene production of thalli irradiated with terminal far‐red is not substantially affected by the presence or absence of CO2, in contrast with the controls which show a clearcut CO2 dependency. Photoreversibility and fiuence response data indicate the involvement of the low energy red'far‐red reversible type of phytochrome action for both the light‐induced ethylene production and the control of epinasty. The far‐red effect is further characterized by a difference in escape from reversibility between light‐induced ethylene production and the elimination of epinasty.

The Influence of Cytokinin and Gibberellin on Auxin Mobilization: Its Role in Regeneration and Apical Dominance in Marchantia polymorpha

Marchantia polymorpha thalli were pulse labeled with 2-14C-IAA, and the relative distribution of that isotope in the dominant and subdominant lobes was determined. The dominance of the primary lobe was marked; mobilization into the secondary lobe could be enhanced by apical excision or disruption of the conducting tissue. Gibberellin and cytokinin also raised the level of isotopic activity in the subdominant lobe, but the influence of cytokinin was only expressed when regeneration was not occurring in the dominant lobe Correlative control of lateral lobe growth and regeneration may be mediated by gradients of these growth regulators established independently at each apex.

INFLUENCE, RÉVERSIBLE PAR LA LUMIÈRE ROUGE‐CLAIR, DE COURTS ÉCLAIREMENTS ROUGE‐FONCÉ A LA FIN DE LA PHOTOPÉRIODE, SUR LA CROISSANCE ET LA TENEUR EN CHLOROPHYLLES DE MARCHANTIA POLYMORPHA L

INFLUENCE, RÉVERSIBLE PAR LA LUMIÈRE ROUGE‐CLAIR, DE COURTS ÉCLAIREMENTS ROUGE‐FONCÉ A LA FIN DE LA PHOTOPÉRIODE, SUR LA CROISSANCE ET LA TENEUR EN CHLOROPHYLLES DE <i>MARCHANTIA POLYMORPHA</i> L

The radiosensitivity of thalli of Marchantia polymorpha L. To acute gamma irradiation

Thalli of Marchantia polymorpha were irradiated with Co 60 gamma rays at exposures up to 55 kR and scored for survival after 4 weeks of growth. The reproductive integrity of the two apical cells of the thalli was inhibited by exposures lower than those required for complete lethality of the thalli. The nuclei of these apical cells are approximately 9·4 times larger than those in the vegetative cells adjacent to the proximal end of the rhizoids (116·6 ±13·0 μ 3 vs. 12·4 ±1·1 μ 3). At the 100 per cent lethal exposure the energy absorbed by the interphase chromosomes of the vegetative cells of the thallus is within the 95 per cent confidence limits as previously predicted for chromosomes of similar size in higher plants. The radiosensitivity of the thallus, however, is different from that of the gemma when sensitivity is based on an energy absorption basis: the thallus is approximately 4·3 times more sensitive than the gemmae.