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Plant & Cell Physiology Oct 2019Chloroplast movement is important for plants to avoid photodamage and to perform efficient photosynthesis. Phototropins are blue light receptors in plants that function...
Chloroplast movement is important for plants to avoid photodamage and to perform efficient photosynthesis. Phototropins are blue light receptors in plants that function in chloroplast movement, phototropism, stomatal opening, and they also affect plant growth and development. In this study, full-length cDNAs of two PHOTOTROPIN genes, PaPHOT1 and PaPHOT2, were cloned from a moth orchid Phalaenopsis aphrodite, and their functions in chloroplast movement were investigated. Phylogenetic analysis showed that PaPHOT1 and PaPHOT2 orthologs were highly similar to PHOT1 and PHOT2 of the close relative Phalaenopsis equestris, respectively, and clustered with monocots PHOT1 and PHOT2 orthologs, respectively. Phalaenopsis aphrodite expressed a moderate level of PaPHOT1 under low blue light of 5 μmol�m-2�s-1 (BL5) and a high levels of PaPHOT1 at >BL100. However, PaPHOT2 was expressed at low levels at
BL100. Analysis of light-induced chloroplast movements using the SPAD method indicated that orchid accumulated chloroplasts at BL25 and significant chloroplast avoidance movement was observed at >BL100. Virus-induced gene silencing of PaPHOTs in orchids showed decreased gene expression of PaPHOTs and reduced both chloroplast accumulation and avoidance responses. Heterologous expression of PaPHOT1 in Arabidopsis phot1phot2 double mutant recovered chloroplast accumulation response at BL5, but neither PaPHOT1 nor PaPHOT2 was able to restore mutant chloroplast avoidance at BL100. Overall, this study showed that phototropins mediate chloroplast movement in Phalaenopsis orchid is blue light-dependent but their function is slightly different from Arabidopsis which might be due to gene evolution. Topics: Arabidopsis Proteins; Chloroplasts; DNA, Complementary; Gene Expression; Gene Silencing; In Situ Hybridization; Light; Mutation; Orchidaceae; Photosynthesis; Phototropins; Phototropism; Phylogeny; Plant Leaves; Plant Proteins; Plants, Genetically Modified; Protein Serine-Threonine Kinases
PubMed: 31198960
DOI: 10.1093/pcp/pcz116 -
Plant & Cell Physiology Mar 2020Plants take up water and nutrients through roots, and uptake efficiency depends on root behavior. Roots recognize the moisture gradient in the soil and grow toward the...
Plants take up water and nutrients through roots, and uptake efficiency depends on root behavior. Roots recognize the moisture gradient in the soil and grow toward the direction of high moisture. This phenomenon is called hydrotropism, and it contributes to efficient water uptake. As nutrients in soil are also unevenly distributed, it is beneficial for plants to grow their roots in the direction of increasing nutrient concentrations, but such a phenomenon has not been demonstrated. Here, we describe the directional growth of roots in response to a nutrient gradient. Using our assay system, the gradient of a nitrogen nutrient, NH4+, was sufficient to stimulate positive tropic responses of rice lateral roots. This phenomenon is a tropism of plant roots to nutrients; hence, we propose the name 'nutritropism'. As well as other tropisms, differential cell elongation was observed before the elongation zone during nutritropism, but the pattern promoting cell elongation preferentially on the non-stimulated side was opposite to those in root hydrotropism and gravitropism. Our evaluation of the NH4+ gradient suggested that the root tips responded to a sub-micromolar difference in NH4+ concentration on both sides of the root. Hydrotropism, gravitropism and phototropism were described in plants as the 'power of movement' by Charles and Francis Darwin in 1880, and these three tropisms have attracted the attention of plant scientists for more than 130 years. Our discovery of nutritropism represents the fourth 'power of movement' in plants and provides a novel root behavioral property used by plants to acquire nutrients efficiently.
Topics: Ammonium Compounds; Biological Transport; Gravitropism; Nitrogen; Nutrients; Oryza; Phototropism; Plant Roots; Soil; Tropism; Water
PubMed: 31808938
DOI: 10.1093/pcp/pcz218 -
Technology and Health Care : Official... 2023Acute sports fatigue impairs athletes' performance and causes other health issues; therefore, an effective method of relieving acute sports fatigue is being researched.
BACKGROUND
Acute sports fatigue impairs athletes' performance and causes other health issues; therefore, an effective method of relieving acute sports fatigue is being researched.
OBJECTIVE
The present study was envisaged to evaluate the effect of electric auto-massage therapy and proprioceptive neuromuscular facilitated (PNF) stretching method on the recovery of acute exercise fatigue using the heart rate variability-based multi-physiological index and RPE scale, and to explore the underlying principle and mechanism.
METHOD
Sixty volunteers were divided into the stretching group, massage group and control group (20 subjects each) using the complete randomization method. The massage group chose the kneading, pressing, tapping and patting techniques using the intelligent massage chair to intervene on the volunteers, the stretching group chose the PNF stretching method to intervene on the volunteers, while the control group did not adopt any of these techniques. The Rating Of Perceived Exertion (RPE) score, heart rate (HR), grip strength, skin electrical activity, heart rate variability (HRV) and blood oxygen saturation (SpO2) of the three groups were recorded before and after the intervention.
RESULTS
Before the intervention, there was no statistically significant difference between the values of heart rate variability (HRV) in the three groups (P> 0.05), while after the intervention, there was a statistically significant difference between the values of heart rate variability - low frequency/high frequency (HRV (LF/HF)) and HRV (HF) in the three groups as: HRV (HF): ηH2= 0.10; P= 0.022; HRV (LF/HF): ηH2= 0.44; P= 0.001. The results indicated that the different intervention methods presented substantial effects on the values of HRV (HF) and HRV (LF/HF) in the volunteers. The HRV (HF) values of massage group, stretching group and control group were compared, and the difference between the massage group and control group was statistically significant (P= 0.019). Further, the HRV (HF) values of massage group rose more significantly than control group after the intervention, and the difference between HRV (HF) values of massage group and stretching group was not statistically significant. When comparing the HRV (LF/HF) values of massage group, stretching group and control group, the differences between the massage group and stretching group and control group were statistically significant (P= 0.001, P< 0.05), and it was observed that the HRV (LF/HF) values of massage group decreased more significantly than those of stretching group and control group after the intervention. The difference in HRV (LF) values between the three groups after the intervention was not statistically significant (P> 0.05).
CONCLUSION
1. It was observed that the electric automatic massage therapy played a vital role in the rapid relief of exercise fatigue by soothing and regulating the human phototropic system, reducing vagal tone, and accelerating the excretion of metabolites; while PNF stretching relieved the exercise fatigue by providing physical and verbal communication to transfer the perception of fatigue, and by promoting the excretion of metabolites through muscle isometric contraction. 2. The effect of electric auto-massage therapy was marginally stronger than the commonly used PNF stretching exercise method.
Topics: Humans; Exercise; Fatigue; Massage; Heart Rate; Athletic Performance
PubMed: 37038791
DOI: 10.3233/THC-236016 -
Science (New York, N.Y.) Nov 2023Intercellular air spaces are necessary for phototropism in .
Intercellular air spaces are necessary for phototropism in .
Topics: Arabidopsis; Arabidopsis Proteins; Light; Mutation; Phototropism; Plant Stems
PubMed: 37995218
DOI: 10.1126/science.adl2394 -
Plant Physiology Mar 2022Efficient foraging by plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms... (Comparative Study)
Comparative Study
Efficient foraging by plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms range from sensing gravity (gravitropism), light (phototropism), water (hydrotropism), touch (thigmotropism), and more. Electrotropism, also known as galvanotropism, is the phenomenon of aligning growth with external electric fields and currents. Although root electrotropism has been observed in a few species since the end of the 19th century, its molecular and physical mechanisms remain elusive, limiting its comparison with the more well-defined sensing pathways in plants. Here, we provide a quantitative and molecular characterization of root electrotropism in the model system Arabidopsis (Arabidopsis thaliana), showing that it does not depend on an asymmetric distribution of the plant hormone auxin, but instead requires the biosynthesis of a second hormone, cytokinin. We also show that the dose-response kinetics of the early steps of root electrotropism follows a power law analogous to the one observed in some physiological reactions in animals. Future studies involving more extensive molecular and quantitative characterization of root electrotropism would represent a step toward a better understanding of signal integration in plants and would also serve as an independent outgroup for comparative analysis of electroreception in animals and fungi.
Topics: Arabidopsis; Cytokinins; Electricity; Gene Expression Regulation, Plant; Genes, Plant; Genetic Variation; Genotype; Plant Roots; Tropism
PubMed: 34893912
DOI: 10.1093/plphys/kiab587 -
Physiology and Molecular Biology of... Jun 2023Root systems anchor plants to the substrate in addition to transporting water and nutrients, playing a fundamental role in plant survival. The gene mediates gravity...
UNLABELLED
Root systems anchor plants to the substrate in addition to transporting water and nutrients, playing a fundamental role in plant survival. The gene mediates gravity signal transduction and participates in root and shoot development and auxin flow in many plants. In this study, a regulator, LsLAZY1, was identified from based on previous transcriptome data. The conserved domain and evolutionary relationship were further analyzed comprehensively. The role of in root development was investigated by genetic transformation and associated gravity response and phototropism assay. Subcellular localization showed that LsLAZY1 was localized in the nucleus. overexpression in () increased the length of the primary roots (PRs) and the number of lateral roots (LRs) compared to . Furthermore, : transgenic seedlings affected auxin transport and showed a stronger gravitational and phototropic responses. It also promoted auxin accumulation at the root tips. These results indicated that affects root development and auxin transport.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s12298-023-01326-4.
PubMed: 37520815
DOI: 10.1007/s12298-023-01326-4 -
PLoS Genetics May 2022Shaded plants challenged with herbivores or pathogens prioritize growth over defense. However, most experiments have focused on the effect of shading light cues on...
Shaded plants challenged with herbivores or pathogens prioritize growth over defense. However, most experiments have focused on the effect of shading light cues on defense responses. To investigate the potential interaction between shade-avoidance and wounding-induced Jasmonate (JA)-mediated signaling on leaf growth and movement, we used repetitive mechanical wounding of leaf blades to mimic herbivore attacks. Phenotyping experiments with combined treatments on Arabidopsis thaliana rosettes revealed that shade strongly inhibits the wound effect on leaf elevation. By contrast, petiole length is reduced by wounding both in the sun and in the shade. Thus, the relationship between the shade and wounding/JA pathways varies depending on the physiological response, implying that leaf growth and movement can be uncoupled. Using RNA-sequencing, we identified genes with expression patterns matching the hyponastic response (opposite regulation by both stimuli, interaction between treatments with shade dominating the wound signal). Among them were genes from the PKS (Phytochrome Kinase Substrate) family, which was previously studied for its role in phototropism and leaf positioning. Interestingly, we observed reduced shade suppression of the wounding effect in pks2pks4 double mutants while a PKS4 overexpressing line showed constitutively elevated leaves and was less sensitive to wounding. Our results indicate a trait-specific interrelationship between shade and wounding cues on Arabidopsis leaf growth and positioning. Moreover, we identify PKS genes as integrators of external cues in the control of leaf hyponasty further emphasizing the role of these genes in aerial organ positioning.
Topics: Arabidopsis; Arabidopsis Proteins; Gene Expression Regulation, Plant; Light; Phytochrome; Plant Leaves
PubMed: 35622862
DOI: 10.1371/journal.pgen.1010213 -
The New Phytologist May 2023PIN-FORMED auxin efflux transporters, a subclass of which is plasma membrane-localised, mediate a variety of land-plant developmental processes via their polar...
PIN-FORMED auxin efflux transporters, a subclass of which is plasma membrane-localised, mediate a variety of land-plant developmental processes via their polar localisation and subsequent directional auxin transport. We provide the first characterisation of PIN proteins in liverworts using Marchantia polymorpha as a model system. Marchantia polymorpha possesses a single PIN-FORMED gene, whose protein product is predicted to be plasma membrane-localised, MpPIN1. To characterise MpPIN1, we created loss-of-function alleles and produced complementation lines in both M. polymorpha and Arabidopsis. In M. polymorpha, gene expression and protein localisation were tracked using an MpPIN1 transgene encoding a translationally fused fluorescent protein. Overexpression of MpPIN1 can partially complement loss of an orthologous gene, PIN-FORMED1, in Arabidopsis. In M. polymorpha, MpPIN1 influences development in numerous ways throughout its life cycle. Most notably, MpPIN1 is required to establish gemmaling dorsiventral polarity and for orthotropic growth of gametangiophore stalks, where MpPIN1 is basally polarised. PIN activity is largely conserved within land plants, with PIN-mediated auxin flow providing a flexible mechanism to organise growth. Specifically, PIN is fundamentally linked to orthotropism and to the establishment of de novo meristems, the latter potentially involving the formation of both auxin biosynthesis maxima and auxin-signalling minima.
Topics: Arabidopsis; Meristem; Arabidopsis Proteins; Marchantia; Phototropism; Gravitropism; Indoleacetic Acids
PubMed: 36880411
DOI: 10.1111/nph.18854 -
Quantitative Plant Biology 2023An increasing number of collaborative projects between artists and scientists raises the question regarding their value, particularly when considering the redirection of...
An increasing number of collaborative projects between artists and scientists raises the question regarding their value, particularly when considering the redirection of resources. Here we provide a personal account of our collaborative efforts, as an artist and a scientist. We propose that one of the most significant outcomes is something that cannot be planned for in advance: serendipitous events. Such events lead to fresh perspectives and imaginative ideas, the fairy dust underlying many great works of art and science. The unexpected nature of these desired outcomes requires from us a leap of faith on the one hand, and a deep trust in our 'partner in crime' on the other.
PubMed: 37587987
DOI: 10.1017/qpb.2023.7 -
Molecules (Basel, Switzerland) Mar 2021Light is a key factor that affects phytochemical synthesis and accumulation in plants. Due to limitations of the environment or cultivated land, there is an urgent need... (Review)
Review
Light is a key factor that affects phytochemical synthesis and accumulation in plants. Due to limitations of the environment or cultivated land, there is an urgent need to develop indoor cultivation systems to obtain higher yields with increased phytochemical concentrations using convenient light sources. Light-emitting diodes (LEDs) have several advantages, including consumption of lesser power, longer half-life, higher efficacy, and wider variation in the spectral wavelength than traditional light sources; therefore, these devices are preferred for in vitro culture and indoor plant growth. Moreover, LED irradiation of seedlings enhances plant biomass, nutrient and secondary metabolite levels, and antioxidant properties. Specifically, red and blue LED irradiation exerts strong effects on photosynthesis, stomatal functioning, phototropism, photomorphogenesis, and photosynthetic pigment levels. Additionally, ex vitro plantlet development and acclimatization can be enhanced by regulating the spectral properties of LEDs. Applying an appropriate LED spectral wavelength significantly increases antioxidant enzyme activity in plants, thereby enhancing the cell defense system and providing protection from oxidative damage. Since different plant species respond differently to lighting in the cultivation environment, it is necessary to evaluate specific wavebands before large-scale LED application for controlled in vitro plant growth. This review focuses on the most recent advances and applications of LEDs for in vitro culture organogenesis. The mechanisms underlying the production of different phytochemicals, including phenolics, flavonoids, carotenoids, anthocyanins, and antioxidant enzymes, have also been discussed.
Topics: Agriculture; Anthocyanins; Antioxidants; Biomass; Carotenoids; Crops, Agricultural; Flavonoids; Luminescence; Nutritive Value; Phenols; Photosynthesis; Phytochemicals; Plant Development; Plants, Medicinal
PubMed: 33803168
DOI: 10.3390/molecules26051477