Photomorphogenic and Chlorophyll Studies in the Bryophyte Marchantia polymorpha

Besides the standard rod (R) and far-red (FK) irradiations, a graded series of different R/FR ratios were tested as 10 min terminal exposures at the end of the daily 8-hour photoperiod of white fluorescent light. Water filtered incandescent light of 3780 lux during 10 min caused A rather weak hut reproducible effect. A superposition to the water layer of different filter combinations shifting the initial transmittance more towards the FR region, and thus gradually lowering the R/FB ratio, resulted in a parallel increase in orthotropic growth and a decrease in chlorophyll content. Our data show growth similarities with the results of other authors on light grown seedlings of higher plants. Rather high levels of the P_FR form of phytochrome seem to he required to maintain horizontal growth and optimal chlorophyll content in Marchantia thalli.     

地钱、拳卷地钱和粗裂地钱的紫外谱线组法鉴别

本文建立了紫外谱线组法鉴别地钱、拳卷地钱和粗裂地钱的方法。通过这三种药材的石油醚、氯仿、乙醇和水提取液的紫外谱线比较,发现地钱、拳卷地钱和粗裂地钱的紫外谱线图、最大吸收峰数目及峰位值具有明显差异。该法简单、准确,可用来鉴别地钱、拳卷地钱和粗裂地钱的原药材。     

Resistance and capacity in the thallus of Marchantia polymorpha

Calculations of the resistance r and capacity c of cell membrances and the resistancer ₁ of cell interiors of a community of cells in Marchantia polymorpha L. thalli are presented. These parameters of a multicellular system were determined by the adaptation of methods employed for the calculation of the resistance and capacity of single cells. The obtained results indicate that such a procedure is justified. A generally accepted resistance-capacity model of the cell was used as a basis for the determination of r, c, and r₁ (representing membrane resistance, membrane capacity, and resistance of cell interior, respectively). The calculations were based on measurements of impedance and phase shift within the frequency range of 5 Hz-1000 Hz. Stainless steel plates were employed as the measuring electrodes; polarization resistance and capacity were determined by separate measurements. The calculations confirmed the assumption that the parameters r, c, and r₁ were constant within the investigated frequency range.
The calculations of resistance and capacity for 25 plants were constant within the investigated frequency range. The calculations of resistance and capacity for 25 plants were carried out by four different methods and they yielded results of the order of : r = 0.45 kΩ± 0.15 kΩ, r₁= 1.0 kΩ± 0.45 kΩ, c = 11 μF ± 3.5 μF. Circular diagrams of impedance also confirmed the validity of the accepted model within the frequency range of 25–300 Hz.     

地钱颈卵器发育和卵发生的显微观察及细胞化学研究

对地钱（Marchantia polymorpha）颈卵器发育和卵发生过程进行了显微观察和细胞化学的研究,颈卵器起始于原始细胞,该细胞呈乳突状,经横分裂产生基细胞和顶细胞,顶细胞经3次纵斜向分裂和1次横分裂产生初生细胞,初生细胞是颈卵器内的第一个细胞,经横分裂产生中央细胞和颈沟母细胞,前者产生1个腹沟细胞和1个卵细胞,后者最终产生4个颈沟细胞。颈卵器的成熟表现为颈部显著伸长和腹部膨大,卵细胞成熟时具有不规则的核,细胞质内含有丰富的囊泡和颗粒物,卵细胞周围充满粘性物质,细胞化学研究表明,该粘性物质为多糖,卵细胞质中深染色的颗粒可能为脂类物质,腹沟细胞自产生后就逐渐退化,颈沟细胞的退化迟于腹沟细胞,其数量通常为4个,偶尔可见5个颈沟细胞或具有双核的现象。     

Glycosylphosphatidylinositol-anchored proteins found in the moss Marchantia polymorpha

A suspension culture of the moss Marchantia polymorpha was incubated with either [3H]ethanolamine or [3H]myristic acid, precursors of a glycosylphosphatidylinositol (GPI) anchor. By both of these a secretory protein of 47 kDa was consistently labelled. Amino acid composition analysis of the chromatographically purified 47-kDa protein exhibited the occurrence of ethanolamine and glucosamine at approximate molar ratios to protein of 1 and 4, respectively. Thus the secretory 47-kDa protein of M. polymorpha was concluded to be a GPI-anchored protein.     

Protoplasts of Marchantia polymorpha and its Development

For the first time protoplasts from normal differentiated thalliof male and female Marchantia polymorpha were prepared by aone step cell wall digestion with 2% Driselase. Cell wall formationonly takes place in light with a carbohydrate source. Furtherconditions for growth and differentiation were studied. Growthalways starts with a primary callus. This can be maintainedby a higher osmolarity of the medium. After reduction of theosmolarity, differentiation appears in three forms: gemmae formationat the callus surface, production of limited growing "cauloids"and transition to an indefinite growing thallus with one orseveral apical regions. (Received December 21, 1987; Accepted February 12, 1988)     

Copper Oxidases in Thalli of the Liverwort Marchantia polymorpha

A study is presented on the properties of copper oxidases in thalli of the liverwort Marchantia polymorpha L. Catecholase and ascorbic acid oxidase are compared in their specific activity, reaction kinetics, inhibitor sensitivity and intracellular localization. It is shown that catecholase is predominantly bound to particulate cell fractions and is normally inhibited by the usual inactivators of copper enzymes. Ascorbic acid oxidase activity, on the other hand, is strongest in the soluble protein fraction and is quite resistant toward the same inhibitors at the pH-optimum of the enzyme. Both enzymes, when assayed with small tissue fragments, can be inhibited as expected.     

Cyclic bis(bibenzyls) and related compounds from the liverworts Marchantia polymorpha and Marchantia palmata

From the methanol extract of the Indian liverwort Marchantia polymorpha, two new cyclic bis(bibenzyls), isomarchantin C and isoriccardin C, and a new phenanthrene derivative, 2-hydroxy-3,7-dimethoxyphenanthrene, were isolated together with the previously known cyclic bis(bibenzyls) marchantin A, C, D and E, riccardin C and perrottetin E and their structures were established by extensive ¹H NMR spectroscopic examination. Isomarchantin C, isoriccardin C, marchantin C and G, and riccardin C were also isolated from the Indian M. palmata. The two Marchantia species are chemically quite similar.     

Chloroplast aggregation during the cold-positioning response in the liverwort Marchantia polymorpha

Journal of Plant Research - Under low-light conditions, chloroplasts localize along periclinal cell walls at temperatures near 20 °C, but they localize along anticlinal cell walls near...     

Microtubule stability affects the unique motility of F-actin in Marchantia polymorpha

Actin microfilaments play crucial roles in diverse plant functions. Some specific cellular processes require interaction between F-actin and microtubules, and it is believed that there are direct or indirect connections between F-actin and microtubules. We previously reported that actin microfilaments exhibit unique dynamic motility in cells of the liverwort, Marchantia polymorpha; the relevance of this activity to microtubules has not been explored. To examine whether the dynamics of F-actin in M. polymorpha were somehow regulated by microtubules, we investigated the effects of stabilization or destabilization of microtubules on dynamics of actin bundles, which were visualized by Lifeact-Venus. To our surprise, both stabilization and destabilization of microtubules exerted similar effects on F-actin motility; apparent sliding movement of F-actin in M. polymorpha cells was accelerated by both oryzalin and paclitaxel, with the effect of paclitaxel more evident than that of oryzalin. Immunofluorescence staining revealed that some F-actin bundles were arrayed along with microtubules in M. polymorpha thallus cells. These results suggest that microtubules play regulatory roles in the unique F-actin dynamics in M. polymorpha.     

Positional cues regulate dorsal organ formation in the liverwort Marchantia polymorpha

Journal of Plant Research - Bryophytes and vascular plants represent the broadest evolutionary divergence in the land plant lineage, and comparative analyses of development spanning this divergence...     

Bioproduction of prostaglandins in a transgenic liverwort, Marchantia polymorpha

Prostaglandins are biologically active substances used in a wide range of medical treatments. Prostaglandins have been supplied mainly by chemical synthesis; nevertheless, the high cost of prostaglandin production remains a factor. To lower the cost of prostaglandin production, we attempted to produce prostaglandins using a liverwort, Marchantia polymorpha L., which accumulates arachidonic acid, which is known as a substrate of prostaglandins. Here we report the first bioproduction of prostaglandins in plant species by introducing a cyclooxygenase gene from a red alga, Gracilaria vermiculophylla into the liverwort. The transgenic liverworts accumulated prostaglandin F_2α, prostaglandin E₂ and prostaglandin D₂ which were not detected in the wild-type liverwort. Moreover, we succeeded in drastically increasing the bioproduction of prostaglandins using an in vitro reaction system with the extracts of transgenic liverworts.     

Induction of Multichotomous Branching by CLAVATA Peptide in Marchantia polymorpha

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Coordination between growth and stress responses by DELLA in the liverwort Marchantia polymorpha

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Ketoisophorone transformation by Marchantia polymorpha and Nicotiana tabacum cultured cells

Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compound ketoisophorone (2,2,6-trimethyl-2-cyclohexene-1,4-dione) (1) by Marchantia polymorpha and Nicotiana tabacum cell suspension cultures produce the chiral products (6R)-levodione (2), (4R,5S)-4-hydroxy-3,3,5-trimethylcyclohexanone (3), and (4R,6R)-actinol (4) as well as the minor components (4R)-hydroxyisophorone (5) and (4S)-phorenol (6).     

Transformations of the Pleiomorphic Plant MTOC during Sporogenesis in the Hepatic Marchantia polymorpha

Sporogenesis in the hepatic Marchantia polymorpha L. provides an outstanding example of the pleiomorphic nature of the plant microtubule organizing center （MTOC）. Microtubules are nucleated from γ-tubuUn in MTOCs that change form during mitosis and meiosis. Following entry of cells into the reproductive pathway of sporogenesis, successive rounds of mitosis give rise to packets of 4-16 sporocytes. Mitotic spindles are organized at discrete polar organizers （POs）, a type of MTOC that is unique to this group of early divergent land plants. An abrupt and radical transformation in microtubule organization occurs when sporocytes enter meiosis： POs are lost and γ-tubulin is closely associated with surfaces of two large elongated plastids that subsequently divide into four. Migration of the four plastid MTOCs into a tetrahedral arrangement establishes the future spore domains and the division polarity of meiosis. As is typical of many bryophytes, cones of microtubules from the four plastid MTOCs initiate a quadripolar microtubule system （QMS） in meiotic prophase. At this point a transformation in the organization of the MTOCs occurs. The γ-tubulin detaches from plastids and forms a diffuse spheroidal pole in each of the spore domains. The plastids, which are no longer MTOCs, continue to divide. The diffuse MTOCs continue to nucleate cones of microtubules during transformation of the QMS to a bipolar spindle. Following meiosis I, γ-tubulin is associated with nuclear envelopes, and the spindles of meiosis II are organized from diffuse MTOCs at the tetrad poles. At simultaneous cytokinesis, radial microtubule systems are organized at nuclear envelope MTOCs in each of the tetrad members.     

Characterization of the plasma membrane H+-ATPase in the liverwort Marchantia polymorpha

The plasma membrane H(+)-ATPase generates an electrochemical gradient of H(+) across the plasma membrane that provides the driving force for solute transport and regulates pH homeostasis and membrane potential in plant cells. Recent studies have demonstrated that phosphorylation of the penultimate threonine in H(+)-ATPase and subsequent binding of a 14-3-3 protein is the major common activation mechanism for H(+)-ATPase in vascular plants. However, there is very little information on the plasma membrane H(+)-ATPase in nonvascular plant bryophytes. Here, we show that the liverwort Marchantia polymorpha, which is the most basal lineage of extant land plants, expresses both the penultimate threonine-containing H(+)-ATPase (pT H(+)-ATPase) and non-penultimate threonine-containing H(+)-ATPase (non-pT H(+)-ATPase) as in the green algae and that pT H(+)-ATPase is regulated by phosphorylation of its penultimate threonine. A search in the expressed sequence tag database of M. polymorpha revealed eight H(+)-ATPase genes, designated MpHA (for M. polymorpha H(+)-ATPase). Four isoforms are the pT H(+)-ATPase; the remaining isoforms are non-pT H(+)-ATPase. An apparent 95-kD protein was recognized by anti-H(+)-ATPase antibodies against an Arabidopsis (Arabidopsis thaliana) isoform and was phosphorylated on the penultimate threonine in response to the fungal toxin fusicoccin in thalli, indicating that the 95-kD protein contains pT H(+)-ATPase. Furthermore, we found that the pT H(+)-ATPase in thalli is phosphorylated in response to light, sucrose, and osmotic shock and that light-induced phosphorylation depends on photosynthesis. Our results define physiological signals for the regulation of pT H(+)-ATPase in the liverwort M. polymorpha, which is one of the earliest plants to acquire pT H(+)-ATPase.