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Journal of Experimental Botany Sep 2023This article comments on: Pang L, Kobayashi A, Atsumi Y, Miyazawa Y, Fujii N, Dietrich D, Bennett MJ, Takahashi H. 2023. MIZU-KUSSEI1 (MIZ1) and GNOM/MIZ2 control not...
This article comments on: Pang L, Kobayashi A, Atsumi Y, Miyazawa Y, Fujii N, Dietrich D, Bennett MJ, Takahashi H. 2023. MIZU-KUSSEI1 (MIZ1) and GNOM/MIZ2 control not only positive hydrotropism but also phototropism in Arabidopsis roots. Journal of Experimental Botany 74, 5026–5038.
Topics: Phototropism; Arabidopsis; Tropism
PubMed: 37702013
DOI: 10.1093/jxb/erad293 -
Journal of Experimental Botany Mar 2023Plants recognize the direction of a light source and exhibit phototropic responses. Physiological studies have predicted that differences in the light intensity received... (Review)
Review
Plants recognize the direction of a light source and exhibit phototropic responses. Physiological studies have predicted that differences in the light intensity received by the cells on the irradiated and shaded sides of a coleoptile or hypocotyl cause differences in the amounts of photoproduct. This hypothetical photoproduct appears to regulate a signaling pathway that controls cell elongation in which cells under lower light intensity elongate more than those under higher light intensity. This results in a bending growth toward a light source and has been proposed as the photoproduct-gradient model of phototropism. In this review, we summarize recent findings on the photosensory adaptation mechanisms involving a blue-light photoreceptor, phototropin1 (phot1), ROOT PHOTOTROPISM2, NONPHOTOTROPIC HYPOCOTYL3 (NPH3), and another photoreceptor family, the phytochromes. The current evidence demonstrates that, in addition to the transition of the phot1-NPH3 photoreceptor complexes to their active state, the presence of a certain population of the phot1-NPH3 complexes showing a steady state, even in a light environment, is essential for recognition of the light source direction in phototropism. This is consistent with the photoproduct-gradient model, and a dissociation state of the phot1-NPH3 complex would be considered an entity of the hypothetical photoproduct in this model.
Topics: Phototropism; Arabidopsis; Arabidopsis Proteins; Hypocotyl; Light
PubMed: 36629282
DOI: 10.1093/jxb/erad015 -
Plant Physiology and Biochemistry : PPB Jul 2021Hypocotyl phototropism is redundantly mediated by phot1 and phot2, two blue light receptor phototropins, under the intensity of blue light>1 μmol m s. As light...
Hypocotyl phototropism is redundantly mediated by phot1 and phot2, two blue light receptor phototropins, under the intensity of blue light>1 μmol m s. As light intensity increases, phot1 inhibits the phot2-mediated response. To date, only Arabidopsis Root Phototropism2 (RPT2) has been shown to participate in phot1-mediated inhibition of phototropism. To dissect the signaling network that underlies phot1-mediated inhibition, we carried out a yeast two-hybrid (Y2H) screening assay for RPT2 interacting proteins and identified J-domain protein required for chloroplast accumulation response 1 (JAC1). The interaction between JAC1 and RPT2 was verified by bimolecular fluorescence complementation and Co-IP assays. JAC1 is expressed mainly in cotyledons and hypocotyls. Like RPT2, JAC1 can be induced by blue light, suggesting that it may function similarly to RPT2 in the inhibition of phototropism. Genetic analysis showed that jac1 mutation significantly enhanced the hypocotyl bending of phot1 mutants towards intermediate-intensity blue light, and this effect was inhibited by the constitutive expression of JAC1 in the phot1 jac1 mutant. The phot1 rpt2 double mutant also exhibited enhanced phototropism compared with the phot1 mutant. Taken together, our data clearly demonstrate that JAC1 cooperates with RPT2 to negatively regulate hypocotyl phototropism in plants and may act either downstream of or in parallel with phot1.
Topics: Arabidopsis; Arabidopsis Proteins; Auxilins; Chloroplasts; Hypocotyl; Light; Phosphoproteins; Phototropism
PubMed: 34023643
DOI: 10.1016/j.plaphy.2021.05.007 -
FEMS Microbiology Letters Mar 2020Stable, long-term interactions between fungi and algae or cyanobacteria, collectively known as lichens, have repeatedly evolved complex architectures with little... (Review)
Review
Stable, long-term interactions between fungi and algae or cyanobacteria, collectively known as lichens, have repeatedly evolved complex architectures with little resemblance to their component parts. Lacking any central scaffold, the shapes they assume are casts of secreted polymers that cement cells into place, determine the angle of phototropic exposure and regulate water relations. A growing body of evidence suggests that many lichen extracellular polymer matrices harbor unicellular, non-photosynthesizing organisms (UNPOs) not traditionally recognized as lichen symbionts. Understanding organismal input and uptake in this layer is key to interpreting the role UNPOs play in lichen biology. Here, we review both polysaccharide composition determined from whole, pulverized lichens and UNPOs reported from lichens to date. Most reported polysaccharides are thought to be structural cell wall components. The composition of the extracellular matrix is not definitively known. Several lines of evidence suggest some acidic polysaccharides have evaded detection in routine analysis of neutral sugars and may be involved in the extracellular matrix. UNPOs reported from lichens include diverse bacteria and yeasts for which secreted polysaccharides play important biological roles. We conclude by proposing testable hypotheses on the role that symbiont give-and-take in this layer could play in determining or modifying lichen symbiotic outcomes.
Topics: Biofilms; Cyanobacteria; Fungi; Lichens; Phylogeny; Polysaccharides; Symbiosis; Uronic Acids
PubMed: 32037451
DOI: 10.1093/femsle/fnaa023 -
Frontiers in Plant Science 2022Pest management has been a great challenge since the beginning of human agricultural activities. Since the 1930s, chemical pesticide control has been a major control... (Review)
Review
Pest management has been a great challenge since the beginning of human agricultural activities. Since the 1930s, chemical pesticide control has been a major control technology that can solve some of the pest problems in agricultural production. Still, it is harmful to food safety and the ecological environment. Meanwhile, the extensive use of chemical pesticides may lead to the rapid development of pest resistance. Because of the advantages of low cost, eco-friendly advantage, and low side effects, Solar Insecticidal Lamp (SIL) as the main physical control technology has been widely used for pest management in agricultural production in China. Owing to the phototaxis of pests, they have a phototropic rhythm during the nighttime. We can adjust the SIL insecticidal time according to the phototropic rhythm of pests. The purpose of this paper is to provide a comprehensive review of the pest phototactic rhythm in a selection of 24 pest species. It is the first comprehensive survey on the phototactic rhythm of pests and the time segments of this survey are accurate to the hour. The phototactic rhythm of pests are investigated in two different varieties of crops: 1) food crops and 2) economic crops. We also discuss and analyze the various factors (e.g., meteorological conditions, insecticidal devices, physiological states and others) that affect the changing phototactic rhythm of pests. Finally, we highlight some open research challenge issues and future directions.
PubMed: 36743546
DOI: 10.3389/fpls.2022.1018711 -
AoB PLANTS Feb 2021In response to gravistimulation under anisotropic light, tree stems showing an active cambium produce reaction wood that redirects the axis of the trees. Several studies...
In response to gravistimulation under anisotropic light, tree stems showing an active cambium produce reaction wood that redirects the axis of the trees. Several studies have described transcriptomic or proteomic models of reaction wood relative to the opposite wood. However, the mechanisms leading to the formation of reaction wood are difficult to decipher because so many environmental factors can induce various signalling pathways leading to this developmental reprogramming. Using an innovative isotropic device where the phototropic response does not interfere with gravistimulation we characterized the early molecular responses occurring in the stem of poplar after gravistimulation in an isotropic environment, and without deformation of the stem. After 30 min tilting at 35° under anisotropic light, we collected the upper and lower xylems from the inclined stems. Controls were collected from vertical stems. We used a microarray approach to identify differentially expressed transcripts. High-throughput real-time PCR allowed a kinetic experiment at 0, 30, 120 and 180 min after tilting at 35°, with candidate genes. We identified 668 differentially expressed transcripts, from which we selected 153 candidates for additional Fluidigm qPCR assessment. Five candidate co-expression gene clusters have been identified after the kinetic monitoring of the expression of candidate genes. Gene ontology analyses indicate that molecular reprogramming of processes such as 'wood cell expansion', 'cell wall reorganization' and 'programmed cell death' occur as early as 30 min after gravistimulation. Of note is that the change in the expression of different genes involves a fine regulation of gibberellin and brassinosteroid pathways as well as flavonoid and phosphoinositide pathways. Our experimental set-up allowed the identification of genes regulated in early gravitropic response without the bias introduced by phototropic and stem bending responses.
PubMed: 33542802
DOI: 10.1093/aobpla/plaa071 -
Plant Physiology May 2020Blue-light-induced chloroplast movements play an important role in maximizing light utilization for photosynthesis in plants. Under a weak light condition, chloroplasts...
Blue-light-induced chloroplast movements play an important role in maximizing light utilization for photosynthesis in plants. Under a weak light condition, chloroplasts accumulate to the cell surface to capture light efficiently (chloroplast accumulation response). Conversely, chloroplasts escape from strong light and move to the side wall to reduce photodamage (chloroplast avoidance response). The blue light receptor phototropin (phot) regulates these chloroplast movements and optimizes leaf photosynthesis by controlling other responses in addition to chloroplast movements. Seed plants such as Arabidopsis () have phot1 and phot2. They redundantly mediate phototropism, stomatal opening, leaf flattening, and the chloroplast accumulation response. However, the chloroplast avoidance response is induced by strong blue light and regulated primarily by phot2. Phots are localized mainly on the plasma membrane. However, a substantial amount of phot2 resides on the chloroplast outer envelope. Therefore, differentially localized phot2 might have different functions. To determine the functions of plasma membrane- and chloroplast envelope-localized phot2, we tethered it to these structures with their respective targeting signals. Plasma membrane-localized phot2 regulated phototropism, leaf flattening, stomatal opening, and chloroplast movements. Chloroplast envelope-localized phot2 failed to mediate phototropism, leaf flattening, and the chloroplast accumulation response but partially regulated the chloroplast avoidance response and stomatal opening. Based on the present and previous findings, we propose that phot2 localized at the interface between the plasma membrane and the chloroplasts is required for the chloroplast avoidance response and possibly for stomatal opening as well.
Topics: Arabidopsis; Arabidopsis Proteins; Cell Membrane; Chloroplasts; Photosynthesis; Phototropins; Phototropism; Plant Leaves; Plants, Genetically Modified
PubMed: 32193212
DOI: 10.1104/pp.20.00059 -
Journal of Integrative Plant Biology Oct 2022Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses...
Plant shoot phototropism is triggered by the formation of a light-driven auxin gradient leading to bending growth. The blue light receptor phototropin 1 (phot1) senses light direction, but how this leads to auxin gradient formation and growth regulation remains poorly understood. Previous studies have suggested phot1's role for regulated apoplastic acidification, but its relation to phototropin and hypocotyl phototropism is unclear. Herein, we show that blue light can cause phot1 to interact with and phosphorylate FERONIA (FER), a known cell growth regulator, and trigger downstream phototropic bending growth in Arabidopsis hypocotyls. fer mutants showed defects in phototropic growth, similar to phot1/2 mutant. FER also interacts with and phosphorylates phytochrome kinase substrates, the phot1 downstream substrates. The phot1-FER pathway acts upstream of apoplastic acidification and the auxin gradient formation in hypocotyl under lateral blue light, both of which are critical for phototropic bending growth in hypocotyls. Our study highlights a pivotal role of FER in the phot1-mediated phototropic cell growth regulation in plants.
Topics: Arabidopsis; Phototropins; Arabidopsis Proteins; Hypocotyl; Phytochrome; Indoleacetic Acids; Light
PubMed: 35924740
DOI: 10.1111/jipb.13336 -
Cells Jan 2021Phototropins are plasma membrane-associated photoreceptors of blue light and UV-A/B radiation. The genome encodes two phototropins, and , that mediate phototropism,...
Phototropins are plasma membrane-associated photoreceptors of blue light and UV-A/B radiation. The genome encodes two phototropins, and , that mediate phototropism, chloroplast positioning, and stomatal opening. They are well characterized in terms of photomorphogenetic processes, but so far, little was known about their involvement in photosynthesis, oxidative stress responses, and cell death. By analyzing , single, and double mutants, we demonstrated that both phototropins influence the photochemical and non-photochemical reactions, photosynthetic pigments composition, stomata conductance, and water-use efficiency. After oxidative stress caused by UV-C treatment, and single and double mutants showed a significantly reduced accumulation of HO and more efficient photosynthetic electron transport compared to the wild type. However, all mutants exhibited higher levels of cell death four days after UV-C treatment, as well as deregulated gene expression. Taken together, our results reveal that on the one hand, both phot1 and phot2 contribute to the inhibition of UV-C-induced foliar cell death, but on the other hand, they also contribute to the maintenance of foliar HO levels and optimal intensity of photochemical reactions and non-photochemical quenching after an exposure to UV-C stress. Our data indicate a novel role for phototropins in the condition-dependent optimization of photosynthesis, growth, and water-use efficiency as well as oxidative stress and cell death response after UV-C exposure.
Topics: Antioxidants; Arabidopsis; Arabidopsis Proteins; Biomass; Cell Death; Fluorescence; Gene Expression Profiling; Gene Expression Regulation, Plant; Homeostasis; Hydrogen Peroxide; Mutation; Oxidative Stress; Photosynthesis; Pigments, Biological; Plant Leaves; Plant Stomata; Protein Serine-Threonine Kinases; RNA, Messenger; Transcriptome; Ultraviolet Rays; Water
PubMed: 33498294
DOI: 10.3390/cells10020200 -
Biochemical and Biophysical Research... Dec 2020Auxin plays an important role in plant growth and development; for example, it regulates the elongation and division of plant cells, the formation of plantlet's...
Auxin plays an important role in plant growth and development; for example, it regulates the elongation and division of plant cells, the formation of plantlet's geotropism and phototropism, and the growth of main lateral roots and hypocotyl. IAA gene is associated with auxin and can response to biotic and abiotic stress in plants. However, the regulatory effect of auxin on anthocyanin accumulation has been rarely reported. In this study, we show that auxin inhibites the accumulation of anthocyanin and decreases the expression of genes related to anthocyanin synthesis in calli, leaves, and seedlings of apple. The expression levels of MdIAA family genes were determined, and we found that MdIAA26 significantly responded to auxin, which also induced MdIAA26 degradation. Functional analysis of MdIAA26 showed that overexpressing MdIAA26 in apple calli and Arabidopsis could promote the accumulation of anthocyanin and up-regulate the genes related to anthocyanin synthesis. Furthermore, the MdIAA26-overexpressing Arabidopsis could counteract auxin-induced inhibition on anthocyanin accumulation, which indicates that auxin inhibits the accumulation of anthocyanin in apple by degrading MdIAA26 protein.
Topics: Anthocyanins; Arabidopsis; Databases, Genetic; Gene Expression Regulation, Plant; Indoleacetic Acids; Malus; Plant Leaves; Plant Proteins; Plants, Genetically Modified; Seedlings; Signal Transduction; Up-Regulation
PubMed: 32981681
DOI: 10.1016/j.bbrc.2020.09.065