Soil-borne fungi alter the apoplastic purinergic signaling in plants by deregulating the homeostasis of extracellular ATP and its metabolite adenosine.

Purinergic signaling activated by extracellular nucleotides and their derivative nucleosides trigger sophisticated signaling networks. The outcome of these pathways determine the capacity of the organism to survive under challenging conditions. Both extracellular ATP (eATP) and Adenosine (eAdo) act as primary messengers in mammals, essential for immunosuppressive responses.

Direct inhibition of phosphate transport by immune signaling in Arabidopsis.

Soil availability of inorganic ortho-phosphate (PO, P) is a key determinant of plant growth and fitness. Plants regulate the capacity of their roots to take up inorganic phosphate by adapting the abundance of H-coupled phosphate transporters of the PHOSPHATE TRANSPORTER 1 (PHT1) family at the plasma membrane (PM) through transcriptional and post-translational changes driven by the genetic network of the phosphate starvation response (PSR). Increasing evidence also shows that plants integrate immune responses to alleviate phosphate starvation stress through the association with beneficial microbes.

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.

Publisher Correction: The calcium-permeable channel OSCA1.3 regulates plant stomatal immunity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The calcium-permeable channel OSCA1.3 regulates plant stomatal immunity.

Perception of biotic and abiotic stresses often leads to stomatal closure in plants. Rapid influx of calcium ions (Ca) across the plasma membrane has an important role in this response, but the identity of the Ca channels involved has remained elusive. Here we report that the Arabidopsis thaliana Ca-permeable channel OSCA1.

Voltage-dependent gating of SV channel TPC1 confers vacuole excitability.

In contrast to the plasma membrane, the vacuole membrane has not yet been associated with electrical excitation of plants. Here, we show that mesophyll vacuoles from Arabidopsis sense and control the membrane potential essentially via the K-permeable TPC1 and TPK channels. Electrical stimuli elicit transient depolarization of the vacuole membrane that can last for seconds.

Auxin-Induced Plasma Membrane Depolarization Is Regulated by Auxin Transport and Not by AUXIN BINDING PROTEIN1.

Auxin is a molecule, which controls many aspects of plant development through both transcriptional and non-transcriptional signaling responses. AUXIN BINDING PROTEIN1 (ABP1) is a putative receptor for rapid non-transcriptional auxin-induced changes in plasma membrane depolarization and endocytosis rates. However, the mechanism of ABP1-mediated signaling is poorly understood.

AUX1-mediated root hair auxin influx governs SCF-type Ca signaling.

Auxin is a key regulator of plant growth and development, but the causal relationship between hormone transport and root responses remains unresolved. Here we describe auxin uptake, together with early steps in signaling, in Arabidopsis root hairs. Using intracellular microelectrodes we show membrane depolarization, in response to IAA in a concentration- and pH-dependent manner.

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.

Cytosolic Ca(2+) Signals Enhance the Vacuolar Ion Conductivity of Bulging Arabidopsis Root Hair Cells.

Plant cell expansion depends on the uptake of solutes across the plasma membrane and their storage within the vacuole. In contrast to the well-studied plasma membrane, little is known about the regulation of ion transport at the vacuolar membrane. We therefore established an experimental approach to study vacuolar ion transport in intact Arabidopsis root cells, with multi-barreled microelectrodes.

Dissection of jasmonate functions in tomato stamen development by transcriptome and metabolome analyses.

Background: Jasmonates are well known plant signaling components required for stress responses and development. A prominent feature of jasmonate biosynthesis or signaling mutants is the loss of fertility. In contrast to the male sterile phenotype of Arabidopsis mutants, the tomato mutant jai1-1 exhibits female sterility with additional severe effects on stamen and pollen development.