Guard cells count the number of unitary cytosolic Ca signals to regulate stomatal dynamics.

Transient stimulus-specific increases in the cytosolic Ca concentration ("calcium signatures") of guard cells have been proposed to regulate the opening and closure of stomatal pores on plant leaves. However, the mechanism by which these Ca signatures are generated and translated into stomatal movement is still largely unresolved. We used a light-gated, Ca-permeable variant of ChannelRhodopsin 2 (ChR2-XXM2.

Light-gated channelrhodopsin sparks proton-induced calcium release in guard cells.

Although there has been long-standing recognition that stimuli-induced cytosolic pH alterations coincide with changes in calcium ion (Ca) levels, the interdependence between protons (H) and Ca remains poorly understood. We addressed this topic using the light-gated channelrhodopsin KCR2 from the pseudofungus , which operates as a H conductive, Ca impermeable ion channel on the plasma membrane of plant cells. Light activation of KCR2 in guard cells evokes a transient cytoplasmic acidification that sparks Ca release from the endoplasmic reticulum.

Trigger hair thermoreceptors provide for heat-induced calcium-electrical excitability in Venus flytrap.

Most plants suffer greatly from heat in general and fire in particular, but some can profit from what is called fire ecology.Dionaea muscipula, the Venus flytrap, is one such plant. In its natural habitat in the Green Swamps, Dionaea often faces challenges from excessive growth of grass and evergreen shrubs that overshadow the plant.

The CIPK23 protein kinase represses SLAC1-type anion channels in Arabidopsis guard cells and stimulates stomatal opening.

Guard cells control the opening of stomatal pores in the leaf surface, with the use of a network of protein kinases and phosphatases. Loss of function of the CBL-interacting protein kinase 23 (CIPK23) was previously shown to decrease the stomatal conductance, but the molecular mechanisms underlying this response still need to be clarified. CIPK23 was specifically expressed in Arabidopsis guard cells, using an estrogen-inducible system.

A unique inventory of ion transporters poises the Venus flytrap to fast-propagating action potentials and calcium waves.

Since the 19 century, it has been known that the carnivorous Venus flytrap is electrically excitable. Nevertheless, the mechanism and the molecular entities of the flytrap action potential (AP) remain unknown. When entering the electrically excitable stage, the trap expressed a characteristic inventory of ion transporters, among which the increase in glutamate receptor GLR3.

The green light gap: a window of opportunity for optogenetic control of stomatal movement.

Green plants are equipped with photoreceptors that are capable of sensing radiation in the ultraviolet-to-blue and the red-to-far-red parts of the light spectrum. However, plant cells are not particularly sensitive to green light (GL), and light which lies within this part of the spectrum does not efficiently trigger the opening of stomatal pores. Here, we discuss the current knowledge of stomatal responses to light, which are either provoked via photosynthetically active radiation or by specific blue light (BL) signaling pathways.

Stalk cell polar ion transport provide for bladder-based salinity tolerance in Chenopodium quinoa.

Chenopodium quinoa uses epidermal bladder cells (EBCs) to sequester excess salt. Each EBC complex consists of a leaf epidermal cell, a stalk cell, and the bladder. Under salt stress, sodium (Na ), chloride (Cl ), potassium (K ) and various metabolites are shuttled from the leaf lamina to the bladders.

Ether anesthetics prevents touch-induced trigger hair calcium-electrical signals excite the Venus flytrap.

Plants do not have neurons but operate transmembrane ion channels and can get electrical excited by physical and chemical clues. Among them the Venus flytrap is characterized by its peculiar hapto-electric signaling. When insects collide with trigger hairs emerging the trap inner surface, the mechanical stimulus within the mechanosensory organ is translated into a calcium signal and an action potential (AP).

Optogenetic control of the guard cell membrane potential and stomatal movement by the light-gated anion channel ACR1.

Guard cells control the aperture of plant stomata, which are crucial for global fluxes of CO and water. In turn, guard cell anion channels are seen as key players for stomatal closure, but is activation of these channels sufficient to limit plant water loss? To answer this open question, we used an optogenetic approach based on the light-gated anion channelrhodopsin 1 (ACR1). In tobacco guard cells that express ACR1, blue- and green-light pulses elicit Cl and NO currents of -1 to -2 nA.

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.

Channelrhodopsin-mediated optogenetics highlights a central role of depolarization-dependent plant proton pumps.

In plants, environmental stressors trigger plasma membrane depolarizations. Being electrically interconnected via plasmodesmata, proper functional dissection of electrical signaling by electrophysiology is basically impossible. The green alga evolved blue light-excited channelrhodopsins (ChR1, 2) to navigate.

Anion channel SLAH3 is a regulatory target of chitin receptor-associated kinase PBL27 in microbial stomatal closure.

In plants, antimicrobial immune responses involve the cellular release of anions and are responsible for the closure of stomatal pores. Detection of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) induces currents mediated via slow-type (S-type) anion channels by a yet not understood mechanism. Here, we show that stomatal closure to fungal chitin is conferred by the major PRRs for chitin recognition, LYK5 and CERK1, the receptor-like cytoplasmic kinase PBL27, and the SLAH3 anion channel.

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.

Wounding-Induced Stomatal Closure Requires Jasmonate-Mediated Activation of GORK K Channels by a Ca Sensor-Kinase CBL1-CIPK5 Complex.

Guard cells integrate various hormone signals and environmental cues to balance plant gas exchange and transpiration. The wounding-associated hormone jasmonic acid (JA) and the drought hormone abscisic acid (ABA) both trigger stomatal closure. In contrast to ABA however, the molecular mechanisms of JA-induced stomatal closure have remained largely elusive.

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.

[Effects of Enhanced Ultraviolet B Irradiation on Photosynthetic and Antioxidant System of Sorghum Seedlings].

The UV-B radiation on the surface of our planet has been enhanced due to gradual thinning of ozone layer. The change of solar spectrum UV-B radiation will cause damage to all kinds of terrestrial plants at certain degree. In this paper, taking breeding sorghum (Sorghum bicolor (L.