A novel O-methyltransferase Cp4MP-OMT catalyses the final step in the biosynthesis of the volatile 1,4-dimethoxybenzene in pumpkin (Cucurbita pepo) flowers.

Background: Floral scents play a crucial role in attracting insect pollinators. Among the compounds attractive to pollinators is 1,4-dimethoxybenzene (1,4-DMB). It is a significant contributor to the scent profile of plants from various genera, including economically important Cucurbita species.

The molecular identity of the characean OH transporter: a candidate related to the SLC4 family of animal pH regulators.

Characeae are closely related to the ancient algal ancestors of all land plants. The long characean cells display a pH banding pattern to facilitate inorganic carbon import in the acid zones for photosynthetic efficiency. The excess OH, generated in the cytoplasm after CO is taken into the chloroplasts, is disposed of in the alkaline band.

Brefeldin A inhibits clathrin-dependent endocytosis and ion transport in Chara internodal cells.

Background: The Characeae are multicellular green algae, which are closely related to higher plants. Their internodal cells are a convenient model to study membrane transport and organelle interactions.

Results: In this study, we report on the effect of brefeldin A (BFA), an inhibitor of vesicle trafficking, on internodal cells of Chara australis.

Dissecting the subcellular membrane proteome reveals enrichment of H+ (co-)transporters and vesicle trafficking proteins in acidic zones of Chara internodal cells.

The Characeae are multicellular green algae with very close relationship to land plants. Their internodal cells have been the subject of numerous (electro-)physiological studies. When exposed to light, internodal cells display alternating bands of low and high pH along their surface in order to facilitate carbon uptake required for photosynthesis.

Surface pH changes suggest a role for H/OH channels in salinity response of Chara australis.

To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H/OH channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl, the main known blocker of animal H channels.

Clathrin in : Molecular Analysis and Involvement in Charasome Degradation and Constitutive Endocytosis.

Charasomes are convoluted plasma membrane domains in characean green algae. They are known to form in response to light via secretion of -Golgi network (TGN) vesicles and local inhibition of endocytosis. Charasomes are involved in the acidification of their aqueous environment, thereby facilitating photosynthesis-dependent carbon uptake.

Is Wortmannin-Induced Reorganization of the trans-Golgi Network the Key to Explain Charasome Formation?

Wortmannin, a fungal metabolite and an inhibitor of phosphatidylinositol-3 (PI3) and phosphatidylinositol-4 (PI4) kinases, is widely used for the investigation and dissection of vacuolar trafficking routes and for the identification of proteins located at multivesicular bodies (MVBs). In this study, we applied wortmannin on internodal cells of the characean green alga Chara australis. Wortmannin was used at concentrations of 25 and 50 μM which, unlike in other cells, arrested neither constitutive, nor wounding-induced endocytosis via coated vesicles.

Convoluted Plasma Membrane Domains in the Green Alga Chara are Depleted of Microtubules and Actin Filaments.

Charasomes are convoluted plasma membrane domains in the green alga Chara australis. They harbor H(+)-ATPases involved in acidification of the medium, which facilitates carbon uptake required for photosynthesis. In this study we investigated the distribution of cortical microtubules and cortical actin filaments in relation to the distribution of charasomes.

Molecular Analysis and Localization of CaARA7 a Conventional RAB5 GTPase from Characean Algae.

RAB5 GTPases are important regulators of endosomal membrane traffic. Among them Arabidopsis thaliana ARA7/RABF2b is highly conserved and homologues are present in fungal, animal and plant kingdoms. In land plants ARA7 and its homologues are involved in endocytosis and transport towards the vacuole.

Molecular and biochemical analysis of the first ARA6 homologue, a RAB5 GTPase, from green algae.

RAB5 GTPases are important regulators of endosomal membrane traffic in yeast, plants, and animals. A specific subgroup of this family, the ARA6 group, has been described in land plants including bryophytes, lycophytes, and flowering plants. Here, we report on the isolation of an ARA6 homologue in a green alga.

The effect of translationally controlled tumour protein (TCTP) on programmed cell death in plants.

Background: Translationally controlled tumour protein (TCTP), a well known protein of the animal kingdom, was shown to be a Ca(2+)-binding protein with important functions in many different cellular processes (e.g. protection against stress and apoptosis, cell growth, cell cycle progression, and microtubule organization).

Investigations on N-rich protein (NRP) of Arabidopsis thaliana under different stress conditions.

Stress response and adaptation are important physiological mechanisms in plants. As plants are not able to avoid stressful environments by moving away, as animals, they have developed diverse mechanisms to respond to stressful situations. One of the genes involved in these mechanisms is NRP (Asparagine-rich protein or N-rich protein).

Cloning of Glucuronokinase from Arabidopsis thaliana, the last missing enzyme of the myo-inositol oxygenase pathway to nucleotide sugars.

Nucleotide sugars are building blocks for carbohydrate polymers in plant cell walls. They are synthesized from sugar-1-phosphates or epimerized as nucleotide sugars. The main precursor for primary cell walls is UDP-glucuronic acid, which can be synthesized via two independent pathways.

Nonradioactive enzyme measurement by high-performance liquid chromatography of partially purified sugar-1-kinase (glucuronokinase) from pollen of Lilium longiflorum.

Here we present a highly sensitive and simple high-performance liquid chromatography (HPLC) method that enables specific quantification of glucuronokinase activity in partially purified extracts from pollen of Lilium longiflorum without radioactive labeled substrates. This assay uses a recombinant UDP-sugar pyrophosphorylase with broad substrate specificity from Pisum sativum (PsUSP) or Arabidopsis thaliana (AtUSP) as a coupling enzyme. Glucuronokinase was partially purified on a DEAE-sepharose column.