The HKT1 Na transporter protects plant fertility by decreasing Na content in stamen filaments.

Salinity stress can greatly reduce seed production because plants are especially sensitive to salt during their reproductive stage. Here, we show that the sodium ion transporter AtHKT1;1 is specifically expressed around the phloem and xylem of the stamen in to prevent a marked decrease in seed production caused by salt stress. The stamens of AtHKT1;1 mutant under salt stress overaccumulate Na, limiting their elongation and resulting in male sterility.

Inter-tissue and inter-organ signaling in drought stress response and phenotyping of drought tolerance.

Plant response to drought stress includes systems for intracellular regulation of gene expression and signaling, as well as inter-tissue and inter-organ signaling, which helps entire plants acquire stress resistance. Plants sense water-deficit conditions both via the stomata of leaves and roots, and transfer water-deficit signals from roots to shoots via inter-organ signaling. Abscisic acid is an important phytohormone involved in the drought stress response and adaptation, and is synthesized mainly in vascular tissues and guard cells of leaves.

Corrigendum: Drought Stress Responses and Resistance in Plants: From Cellular Responses to Long-Distance Intercellular Communication.

[This corrects the article DOI: 10.3389/fpls.2020.

Targeted permeabilization of the cell wall and extraction of charged molecules from single cells in intact plant clusters using a focused electric field.

The extraction of cellular contents from plant cells covered with cell walls remains a challenge, as it is physically hindered by the cell wall. We present a new microfluidic approach that leverages an intense pulsed electric field for permeabilizing the cell wall and a focused DC electric field for extracting the cellular contents selectively from a few targeted cells in a cluster of intact plant cells. We coupled the approach with on-chip fluorescence quantification of extracted molecules leveraging isotachophoresis as well as off-chip reverse transcription-quantitative polymerase chain reaction detecting extracted mRNA molecules.

Drought Stress Responses and Resistance in Plants: From Cellular Responses to Long-Distance Intercellular Communication.

The drought stress responses of vascular plants are complex regulatory mechanisms because they include various physiological responses from signal perception under water deficit conditions to the acquisition of drought stress resistance at the whole-plant level. It is thought that plants first recognize water deficit conditions in roots and that several molecular signals then move from roots to shoots. Finally, a phytohormone, abscisic acid (ABA) is synthesized mainly in leaves.

Brachypodium BdABCG25 is a homolog of Arabidopsis AtABCG25 involved in the transport of abscisic acid.

Abscisic acid (ABA), a stress hormone produced by plants to cope with various environmental stresses, has potential as a mobile molecule. Recently, several types of ABA transporters have been described. We previously found a membrane transporter, AtABCG25, that is involved in intercellular ABA transport in Arabidopsis thaliana.

Evidence for potassium transport activity of Arabidopsis KEA1-KEA6.

Arabidopsis thaliana contains the putative K efflux transporters KEA1-KEA6, similar to KefB and KefC of Escherichia coli. KEA1-KEA3 are involved in the regulation of photosynthetic electron transport and chloroplast development. KEA4-KEA6 mediate pH regulation of the endomembrane network during salinity stress.

SnRK1 Kinase and the NAC Transcription Factor SOG1 Are Components of a Novel Signaling Pathway Mediating the Low Energy Response Triggered by ATP Depletion.

Plant growth is strictly controlled by cell division, elongation, and differentiation for which adequate supplies of intracellular ATP are required. However, it is unclear how changes in the amount of intracellular ATP affect cell division and growth. To reveal the specific pathway dependent on ATP concentration, we performed analyses on the mitochondria mutation .

Regulatory Gene Networks in Drought Stress Responses and Resistance in Plants.

Plant responses to drought stress have been analyzed extensively to reveal complex regulatory gene networks, including the detection of water deficit signals, as well as the physiological, cellular, and molecular responses. Plants recognize water deficit conditions at their roots and transmit this signal to their shoots to synthesize abscisic acid (ABA) in their leaves. ABA is a key phytohormone that regulates physiological and molecular responses to drought stress, such as stomatal closure, gene expression, and the accumulation of osmoprotectants and stress proteins.

ABA Transport and Plant Water Stress Responses.

To understand the integrative networks of signaling molecules, the sites of their biosynthesis and action must be clarified, particularly for phytohormones such as abscisic acid (ABA). The relationship between the sites of ABA biosynthesis and transport has been discussed extensively in the context of guard cells and stomatal regulation. However, guard cells are not the only site of ABA action.

Functional relationship of AtABCG21 and AtABCG22 in stomatal regulation.

Stomatal regulation is important for water transpiration from plants. Stomatal opening and closing are controlled by many transporter proteins in guard cells. AtABCG22 is a member of the ATP-binding cassette (ABC) transporters and is a stomatal regulator; however, the function of AtABCG22 has not yet been determined fully, although a mutant phenotype included a significant effect on stomatal status.

Erratum: Acetate-mediated novel survival strategy against drought in plants.

This corrects the article DOI: 10.1038/nplants.2017.

Acetate-mediated novel survival strategy against drought in plants.

Water deficit caused by global climate changes seriously endangers the survival of organisms and crop productivity, and increases environmental deterioration. Plants' resistance to drought involves global reprogramming of transcription, cellular metabolism, hormone signalling and chromatin modification. However, how these regulatory responses are coordinated via the various pathways, and the underlying mechanisms, are largely unknown.

Overexpression of AtABCG25 enhances the abscisic acid signal in guard cells and improves plant water use efficiency.

In addition to improving drought tolerance, improvement of water use efficiency is a major challenge in plant physiology. Due to their trade-off relationships, it is generally considered that achieving stress tolerance is incompatible with maintaining stable growth. Abscisic acid (ABA) is a key phytohormone that regulates the balance between intrinsic growth and environmental responses.

AtPHT4;4 is a chloroplast-localized ascorbate transporter in Arabidopsis.

Ascorbate is an antioxidant and coenzyme for various metabolic reactions in vivo. In plant chloroplasts, high ascorbate levels are required to overcome photoinhibition caused by strong light. However, ascorbate is synthesized in the mitochondria and the molecular mechanisms underlying ascorbate transport into chloroplasts are unknown.

Intertissue signal transfer of abscisic acid from vascular cells to guard cells.

Abscisic acid (ABA) is a phytohormone that responds to environmental stresses, such as water deficiency. Recent studies have shown that ABA biosynthetic enzymes are expressed in the vascular area under both nonstressed and water-stressed growth conditions. However, specific cells in the vasculature involved in ABA biosynthesis have not been identified.

RARGE II: an integrated phenotype database of Arabidopsis mutant traits using a controlled vocabulary.

Arabidopsis thaliana is one of the most popular experimental plants. However, only 40% of its genes have at least one experimental Gene Ontology (GO) annotation assigned. Systematic observation of mutant phenotypes is an important technique for elucidating gene functions.

SD3, an Arabidopsis thaliana homolog of TIM21, affects intracellular ATP levels and seedling development.

It is poorly understood how plants control their growth by cell division, elongation, and differentiation. We have characterized a seedling-lethal mutant segregation distortion 3 (sd3) that showed a very dwarf phenotype when grown in the light and, in the dark, had short hypocotyls with reduced ploidy levels. The corresponding gene of SD3 encodes a protein with high similarity to yeast translocase on the inner mitochondrial membrane 21 (TIM21), which is a component of the TIM23 complex.

Two glycosyltransferases involved in anthocyanin modification delineated by transcriptome independent component analysis in Arabidopsis thaliana.

To identify candidate genes involved in Arabidopsis flavonoid biosynthesis, we applied transcriptome coexpression analysis and independent component analyses with 1388 microarray data from publicly available databases. Two glycosyltransferases, UGT79B1 and UGT84A2 were found to cluster with anthocyanin biosynthetic genes. Anthocyanin was drastically reduced in ugt79b1 knockout mutants.

Arabidopsis mutant of AtABCG26, an ABC transporter gene, is defective in pollen maturation.

In plants, pollen is the male gametophyte that is generated from microspores, which are haploid cells produced after meiosis of diploid pollen mother cells in floral anthers. In normal maturation, microspores interact with the tapetum, which consists of one layer of metabolically active cells enclosing the locule in anthers. The tapetum plays several important roles in the maturation of microspores.

Arabidopsis mutants of AtABCG22, an ABC transporter gene, increase water transpiration and drought susceptibility.

In plants, water vapour is released into the atmosphere through stomata in a process called transpiration. Abscisic acid (ABA) is a key phytohormone that facilitates stomatal closure through its action on guard cells. Recently, ATP-binding cassette (ABC) transporter genes, AtABCG25 and AtABCG40, were shown to be involved in ABA transport and responses.

Molecular basis of the core regulatory network in ABA responses: sensing, signaling and transport.

ABA is a major phytohormone that regulates a broad range of plant traits and is especially important for adaptation to environmental conditions. Our understanding of the molecular basis of ABA responses in plants improved dramatically in 2009 and 2010, banner years for ABA research. There are three major components; PYR/PYL/ RCAR (an ABA receptor), type 2C protein phosphatase (PP2C; a negative regulator) and SNF1-related protein kinase 2 (SnRK2; a positive regulator), and they offer a double negative regulatory system, [PYR/PYL/RCAR-| PP2C-| SnRK2].

ABA transport factors found in Arabidopsis ABC transporters.

Abscisic acid (ABA) is a phytohormone that plays an important role in responses to environmental stresses as well as seed maturation and germination. Intracellular signaling by ABA has been rigorously investigated in relation to stomatal guard-cell regulation, seed germination, and abiotic stress responses. However, intercellular regulation of ABA, including the molecular basis of ABA transport systems, has hardly been examined in any plant species.

Functional compensation of primary and secondary metabolites by duplicate genes in Arabidopsis thaliana.

It is well known that knocking out a gene in an organism often causes no phenotypic effect. One possible explanation is the existence of duplicate genes; that is, the effect of knocking out a gene is compensated by a duplicate copy. Another explanation is the existence of alternative pathways.

Toward genome-wide metabolotyping and elucidation of metabolic system: metabolic profiling of large-scale bioresources.

An improvement in plant production is increasingly important for a sustainable human society. For this purpose, understanding the mechanism of plant production, that is, the plant metabolic system, is an immediate necessity. After the sequencing of the Arabidopsis genome, it has become possible to obtain a bird's eye view of its metabolism by means of omics such as transcriptomics and proteomics.