Tagged: Arabidopsis thaliana

Functional and chemical characterization of XAF

Plants rely on stiff cells walls for support. But these same cell walls have to be flexible to grow when required. Nguyen-Phan and Fry examine a chemical that regulates how this happens. Plant cell walls have many demands put upon them. As plants lack skeletons, the job of supporting the plant rests on their rigidity. However, plants also need to be able to move, despite having no muscles. The same plant cell walls, therefore, also need flexibility. A common problem cell walls face is water. When a plant needs to flex, it can fill its vacuoles up with water. This...

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Diagram of the chemical process

Nitrate nutrition improves energy efficiency under hypoxic stress

Plants take up and assimilate nitrogen (N) in the form of nitrate (NO3–) or ammonium (NH4+), or a combination of both. When oxygen availability is reduced (hypoxia), plants need to generate energy to survive and protect themselves against the hypoxia-induced damage. Wany et al. investigate the role of NO3– or NH4+ on increasing energy efficiency under hypoxia in Arabidopsis. They find that hypoxic stress under NO3– nutrition leads to increased nitrate reductase activity, nitric oxide (NO) production, class 1 phytoglobin gene expression, and in turn ATP production. These effects were reduced under NH4+ nutrition. The results indicate that NO3–nutrition influences multiple factors in order to increase...

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Characterization of a CONSTANS-Like gene induced in spaceflight

The complex networks and signalling pathways that equip plants to cope with environmental challenges in terrestrial environments developed over evolutionary time. Exposing plants to novel environments presents opportunities to understand how plants adjust to conditions outside their evolutionary experience. Spaceflight is one such environment and understanding how plants function outside of Earth’s boundaries is also integral to space exploration. Plants respond to spaceflight in ways that are dependent on species, ecotype, genetics and even organs. The physiological impact of spaceflight is reflected in the patterns of gene expression. For example, spaceflight-grown Arabidopsis roots tend to be smaller, have fewer lateral roots...

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A touching example

Calcium signaling regulates the protein VIP1 in touch responses in Arabidopsis

How can plants perceive mechanical stress such as touch? Calcium and several proteins are known to be involved, but it is still unclear how they interact. VIP1 of the model plant Arabidopsis thaliana is a bZIP (basic Leucine Zipper Domain) transcription factor and one of such proteins. When cells perceive mechanical stress, VIP1 moves from the cytosol to the nucleus, changes gene expression patterns, and regulates root bending, which helps roots avoid obstacles. Tsugama et al. report that VIP1 binds to the calcium-binding calmodulin proteins, and that its nuclear-cytoplasmic shuttling requires calcium. This study can help find novel regulators of...

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MeJA contributes to the regulation of the trade-off between defence mode and plant growth

COI1-dependent growth, proteomic and metabolomic changes

Plant cell suspensions provide a model to study the apoplast and to monitor metabolic and cell cycle-related changes. Bömer et al. frame a case study for the stable transformation of Arabidopsis cell cultures identifying CORONATINE INSENSITIVE 1 (COI1)-dependent changes in cell wall proteins, cell division and expansion, and availability of metabolites. A role for methyl jasmonate (MeJA) in regulating the trade-off between defence mode and plant growth, by inhibiting cell proliferation and promoting changes in cell wall composition, is supported. This study contributes to the understanding of the regulation of growth and the production of metabolic resources by JAs and...

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Arabidopsis

Adaptation of ecological strategies to climate within species

In Grime’s C-S-R strategy model, plant ecological strategies vary between ruderals (R), stress-tolerators (S) and competitors (C). These variations are assumed to reflect adaptation of species to the environment, although the relationships with environmental factors such as climate remain debated. Moreover, adaptive processes such as selection and diversification need to be tested within species. Vasseur et al. show that C-S-R strategies diversify with climate between lineages of Arabidopsis thaliana. Intraspecific variations notably result from a selection gradient on stress-tolerance and ruderality with latitude. This highlights the potential of merging functional ecology and biogeography with evolutionary genomics to understand plant adaptation...

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Details of the surface of primary roots

Root hair abundance impacts cadmium accumulation in Arabidopsis thaliana shoots

Root hairs increase the contact area of roots with soil and thereby enhance the capacity for solute uptake. The strict hair/non-hair pattern of Arabidopsis thaliana can change with nutrient deficiency or exposure to toxic elements, which modify root hair density. Kohanová et al. assess the effects of root hairs on cadmium (Cd) uptake and translocation by comparing the Arabidopsis thaliana ecotype Columbia (Col-0) with mutants lacking root hairs (rhd6-1, cpc/try) and a mutant in which most rhizodermal cells develop into hairs (wer/myb23). The results indicate that root hair density can have a large effect on Cd accumulation in shoots, suggesting...

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Arabidopsis roots

Actin cytoskeleton, plant growth and development in Arabidopsis root hair mutant der1-3

The DER1 (deformed root hairs1) locus encodes a major vegetative actin (ACTIN2) in Arabidopsis thaliana. Mutations in DER1 lead to impaired root hair development. However, the role of this gene in overall plant development has not been defined. Using plant phenotyping, immunofluorescence localization, vital staining and live cell imaging, Vaškebová et al. characterise plant growth and organization of the actin cytoskeleton in cells of cotyledons, hypocotyls and roots of der1-3 mutant. They demonstrate a pleiotropic phenotype of this mutant depending on the actin cytoskeleton organisation and deregulation of cell division plane orientation, resulting in wavy root growth pattern.

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Cell signalling diagram

Methanol-induced cell signalling processes

Methanol is a frequently used solvent, and a volatile organic compound (VOC) released from plant cell walls through the action of pectin methylesterases. Tran et al. show that cell wall-produced methanol is a signal in plant immunity and interplant communication. This VOC is able to effectively induce a rapid signalling process dependent on reactive oxygen species (ROS) generation and cytosolic Ca2+ variations. These lead to plant responses to pathogens such as plasma membrane depolarization through anion channel regulation and ethylene synthesis.

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A diagram of the paper

ARP2/3 complex links cell wall assembly and auxin distribution

The protein complex ARP2/3 is responsible for nucleating actin, and its loss results in multiple defects in young seedlings of Arabidopsis thaliana. Sahi et al. show that plants lacking the ARP2/3 complex have defects associated with cell wall synthesis. Mature tissues of inflorescence stems contain less cellulose and more homogalacturonan, cell walls are thinner, and lignification is altered. Stems of mutant plants have reduced basipetal auxin transport and a changed auxin influx carrier (AUX1) expression pattern. Since cell wall composition and auxin transport are functionally connected, morphogenetic defects may be explained by ARP2/3 control of cell wall synthesis and/or auxin...

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A. thaliana plants grown for the experiment

Quantifying temporal change in plant population attributes: insights from a resurrection approach

Plant populations vary over time as a result of the effects of environmental variation on life-cycle traits and genetic diversity. It is important to quantify how much populations actually change over time to better understand the response of plants to rapid environmental shifts, such as those imposed by global climate change. A recent study by Gómez et al., and published as an Editor’s Choice article in AoBP, quantifies the extent of phenotypic and genetic change over time in natural populations of the annual plant Arabidopsis thaliana. The authors grew seeds from four well-known Spanish A. thaliana populations sampled in either...

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Arabidopsis

Effects of nitrogen and phosphorus supply on stoichiometry of six elements in leaves of Arabidopsis thaliana

Plant elemental composition is of fundamental importance for plant growth and metabolic functions. However, knowledge of how multi-elemental stoichiometry responds to varying nitrogen (N) and phosphorus (P) availabilities remains limited. Yan et al. conducted experimental manipulations with nine repeat experiments to investigate the effects of N and P supply on the concentrations and variability of six elements, carbon (C), N, P, potassium (K), calcium (Ca) and magnesium (Mg), in leaves of Arabidopsis thaliana. N and P supplies exerted differential influences on the concentrations of C, N, P, K, Ca and Mg in green leaves. The specific C content should be...

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tps22 and selenium

The role of the TPS22 gene in selenium tolerance

Excess selenium (Se) is toxic to plants; however, relatively little information is known about the regulatory mechanism of plant Se tolerance. Jiang et al. report a novel role of the TPS22 (terpenoid synthase) gene in Se tolerance in Arabidopsis using mutant screening, gene cloning and expression studies. Their findings reveal that cytokinin is downregulated and involved in TPS22-mediated Se tolerance by affecting the key gene expression of Se uptake and Se metabolism detoxification. This study sheds light on the mechanism of Se detoxification and tolerance in plants.

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