Physical and Chemical Traits of Grape Varieties Influence Preferences and Performance.

The cuticle-covered surface forms the interface between plant parts, including fruits, and their environment. The physical and chemical properties of fruit surfaces profoundly influence plant-frugivore interactions by shaping the susceptibility and suitability of the host for the attacker. Grapevine (, Vitaceae) serves as one of the various host plants of the spotted wing drosophila, Matsumura (Diptera: Drosophilidae), which is invasive in several parts of the world and can cause major crop losses.

Plant apocarotenoid metabolism utilizes defense mechanisms against reactive carbonyl species and xenobiotics.

Carotenoid levels in plant tissues depend on the relative rates of synthesis and degradation of the molecules in the pathway. While plant carotenoid biosynthesis has been extensively characterized, research on carotenoid degradation and catabolism into apocarotenoids is a relatively novel field. To identify apocarotenoid metabolic processes, we characterized the transcriptome of transgenic Arabidopsis (Arabidopsis thaliana) roots accumulating high levels of β-carotene and, consequently, β-apocarotenoids.

Developmental pattern of grapevine (Vitis vinifera L.) berry cuticular wax: Differentiation between epicuticular crystals and underlying wax.

The grapevine berry surface is covered by a cuticle consisting of cutin and various lipophilic wax compounds. The latter build the main barrier for transpirational water loss and protect the fruit against environmental factors e.g.

A voltage-dependent Ca homeostat operates in the plant vacuolar membrane.

Cytosolic calcium signals are evoked by a large variety of biotic and abiotic stimuli and play an important role in cellular and long distance signalling in plants. While the function of the plasma membrane in cytosolic Ca signalling has been intensively studied, the role of the vacuolar membrane remains elusive. A newly developed vacuolar voltage clamp technique was used in combination with live-cell imaging, to study the role of the vacuolar membrane in Ca and pH homeostasis of bulging root hair cells of Arabidopsis.

An optimized genetically encoded dual reporter for simultaneous ratio imaging of Ca and H reveals new insights into ion signaling in plants.

Whereas the role of calcium ions (Ca ) in plant signaling is well studied, the physiological significance of pH-changes remains largely undefined. Here we developed CapHensor, an optimized dual-reporter for simultaneous Ca and pH ratio-imaging and studied signaling events in pollen tubes (PTs), guard cells (GCs), and mesophyll cells (MCs). Monitoring spatio-temporal relationships between membrane voltage, Ca - and pH-dynamics revealed interconnections previously not described.

Compositional, structural and functional cuticle analysis of Prunus laurocerasus L. sheds light on cuticular barrier plasticity.

Barrier properties of the hydrophobic plant cuticle depend on its physicochemical composition. The cuticular compounds vary considerably among plant species but also among organs and tissues of the same plant and throughout developmental stages. As yet, these intraspecific modifications at the cuticular wax and cutin level are only rarely examined.

Induction of Jasmonoyl-Isoleucine (JA-Ile)-Dependent Genes in NaCl-Treated Roots Can Occur at Very Low JA-Ile Levels and in the Absence of the JA/JA-Ile Transporter JAT1/AtABCG16.

The plant hormone jasmonoyl-isoleucine (JA-Ile) is an important regulator of plant growth and defense in response to various biotic and abiotic stress cues. Under our experimental conditions, JA-Ile levels increased approximately seven-fold in NaCl-treated roots. Although these levels were around 1000-fold lower than in wounded leaves, genes of the JA-Ile signaling pathway were induced by a factor of 100 or more.

Stabilization of desmoglein-2 binding rescues arrhythmia in arrhythmogenic cardiomyopathy.

Arrhythmogenic cardiomyopathy (AC) is a genetic disease causing arrhythmia and sudden cardiac death with only symptomatic therapy available at present. Mutations of desmosomal proteins, including desmoglein-2 (Dsg2) and plakoglobin (Pg), are the major cause of AC and have been shown to lead to impaired gap junction function. Recent data indicated the involvement of anti-Dsg2 autoantibodies in AC pathogenesis.

Leaf cuticle analyses: implications for the existence of cutan/non-ester cutin and its biosynthetic origin.

Background And Aims: The cuticle of a limited number of plant species contains cutan, a chemically highly resistant biopolymer. As yet, the biosynthesis of cutan is not fully understood. Attempting to further unravel the origin of cutan, we analysed the chemical composition of enzymatically isolated cuticular membranes of Agave americana leaves.

Cuticular wax coverage and its transpiration barrier properties in Quercus coccifera L. leaves: does the environment matter?

Plants prevent uncontrolled water loss by synthesizing, depositing and maintaining a hydrophobic layer over their primary aerial organs-the plant cuticle. Quercus coccifera L. can plastically respond to environmental conditions at the cuticular level.

Cuticular wax coverage and its transpiration barrier properties in Quercus coccifera L. leaves: does the environment matter?

Plants prevent uncontrolled water loss by synthesizing, depositing and maintaining a hydrophobic layer over their primary aerial organs-the plant cuticle. Quercus coccifera L. can plastically respond to environmental conditions at the cuticular level.

Calcium signals in guard cells enhance the efficiency by which abscisic acid triggers stomatal closure.

During drought, abscisic acid (ABA) induces closure of stomata via a signaling pathway that involves the calcium (Ca )-independent protein kinase OST1, as well as Ca -dependent protein kinases. However, the interconnection between OST1 and Ca signaling in ABA-induced stomatal closure has not been fully resolved. ABA-induced Ca signals were monitored in intact Arabidopsis leaves, which express the ratiometric Ca reporter R-GECO1-mTurquoise and the Ca -dependent activation of S-type anion channels was recorded with intracellular double-barreled microelectrodes.

Molecular and electrophysiological characterization of anion transport in Arabidopsis thaliana pollen reveals regulatory roles for pH, Ca and GABA.

We investigated the molecular basis and physiological implications of anion transport during pollen tube (PT) growth in Arabidopsis thaliana (Col-0). Patch-clamp whole-cell configuration analysis of pollen grain protoplasts revealed three subpopulations of anionic currents differentially regulated by cytoplasmic calcium ([Ca ] ). We investigated the pollen-expressed proteins AtSLAH3, AtALMT12, AtTMEM16 and AtCCC as the putative anion transporters responsible for these currents.

UV-C irradiation compromises conidial germination, formation of appressoria, and induces transcription of three putative photolyase genes in the barley powdery mildew fungus, Blumeria graminis f. sp. hordei.

UV-C irradiation is known to compromise germination of Blumeria graminis conidia and to reduce powdery mildew infestation. However, only scarce information is available on the effects of UV-C irradiation on B. graminis appressorium formation.

An interconnection between tip-focused Ca and anion homeostasis controls pollen tube growth.

Plant reproduction is the basis for economically relevant food production. It relies on pollen tube (PTs) growth into the female flower organs for successful fertilization. The high cytosolic Ca concentration ([Ca]) at the PT tip is sensed by Ca-dependent protein kinases (CPKs) that in turn activate R- and S-type anion channels to control polar growth.

Mycorrhizal lipochitinoligosaccharides (LCOs) depolarize root hairs of Medicago truncatula.

Arbuscular Mycorrhiza and Root Nodule Symbiosis are symbiotic interactions with a high benefit for plant growth and crop production. Thus, it is of great interest to understand the developmental process of these symbioses in detail. We analysed very early symbiotic responses of Medicago truncatula root hair cells, by stimulation with lipochitinoligosaccharides specific for the induction of nodules (Nod-LCOs), or the interaction with mycorrhiza (Myc-LCOs).

Spatio-temporal Aspects of Ca2+ Signalling: Lessons from Guard Cells and Pollen Tubes.

Changes in cytosolic Ca2+ concentration ([Ca2+]cyt) serve to transmit information in eukaryotic cells. The involvement of this second messenger in plant cell growth as well as osmotic- and water relations is well established. After almost 40 years of intense research on the coding and decoding of plant Ca2+ signals, numerous proteins involved in Ca2+ action have been identified.

Guard cells in fern stomata are connected by plasmodesmata, but control cytosolic Ca levels autonomously.

Recent studies have revealed that some responses of fern stomata to environmental signals differ from those of their relatives in seed plants. However, it is unknown whether the biophysical properties of guard cells differ fundamentally between species of both clades. Intracellular micro-electrodes and the fluorescent Ca reporter FURA2 were used to study voltage-dependent cation channels and Ca signals in guard cells of the ferns Polypodium vulgare and Asplenium scolopendrium.

Direct Effects of Physcion, Chrysophanol, Emodin, and Pachybasin on Germination and Appressorium Formation of the Barley ( Hordeum vulgare L.) Powdery Mildew Fungus Blumeria graminis f. sp. hordei (DC.) Speer.

Several anthraquinone derivatives are active components of fungicidal formulations particularly effective against powdery mildew fungi. The antimildew effect of compounds such as physcion and chrysophanol is largely attributed to host plant defense induction. However, so far a direct fungistatic/fungicidal effect of anthraquinone derivatives on powdery mildew fungi has not been unequivocally demonstrated.

Tip-localized Ca -permeable channels control pollen tube growth via kinase-dependent R- and S-type anion channel regulation.

Pollen tubes (PTs) are characterized by having tip-focused cytosolic calcium ion (Ca ) concentration ([Ca ] ) gradients, which are believed to control PT growth. However, the mechanisms by which the apical [Ca ] orchestrates PT growth are not well understood. Here, we aimed to identify these mechanisms by combining reverse genetics, cell biology, electrophysiology, and live-cell Ca and anion imaging.

Ants contribute to pollination but not to reproduction in a rare calcareous grassland forb.

The number of plants pollinated by ants is surprisingly low given the abundance of ants and the fact that they are common visitors of angiosperms. Generally ants are considered as nectar robbers that do not provide pollination service. We studied the pollination system of the endangered dry grassland forb and found two ant species to be the most frequent visitors of its flowers.

A Poly(A) Ribonuclease Controls the Cellotriose-Based Interaction between and Its Host Arabidopsis.

, an endophytic root-colonizing fungus, efficiently promotes plant growth and induces resistance to abiotic stress and biotic diseases. fungal cell wall extract induces cytoplasmic calcium elevation in host plant roots. Here, we show that cellotriose (CT) is an elicitor-active cell wall moiety released by into the medium.

Very-long-chain aldehydes induce appressorium formation in ascospores of the wheat powdery mildew fungus Blumeria graminis.

Asexually produced conidia of the wheat powdery mildew fungus Blumeria graminis f. sp. tritici (Bgt) are known to perceive cuticular very-long-chain aldehydes as signal substances strongly stimulating germination and differentiation of infection structures in a concentration- and chain-length-dependent manner.

A Dual Role for the OsK5.2 Ion Channel in Stomatal Movements and K Loading into Xylem Sap.

The roles of potassium channels from the Shaker family in stomatal movements have been investigated by reverse genetics analyses in Arabidopsis (), but corresponding information is lacking outside this model species. Rice () and other cereals possess stomata that are more complex than those of Arabidopsis. We examined the role of the outward Shaker K channel gene Expression of the gene ( reporter strategy) was observed in the whole stomatal complex (guard cells and subsidiary cells), root vasculature, and root cortex.