scholarly journals Regulation of plant phototropic growth by NPH3/RPT2-like substrate phosphorylation and 14-3-3 binding

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Stuart Sullivan ◽  
Thomas Waksman ◽  
Dimitra Paliogianni ◽  
Louise Henderson ◽  
Melanie Lütkemeyer ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plant Growth ◽  
Consensus Sequence ◽  
Light Environment ◽  
Common Mechanism ◽  
Growth Responses ◽  
Directional Growth ◽  
Agc Kinases ◽  
Substrate Phosphorylation

AbstractPolarity underlies all directional growth responses in plants including growth towards the light (phototropism). The plasma-membrane associated protein, NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key determinant of phototropic growth which is regulated by phototropin (phot) AGC kinases. Here we demonstrate that NPH3 is directly phosphorylated by phot1 within a conserved C-terminal consensus sequence (RxS) that is necessary to promote phototropism and petiole positioning in Arabidopsis. RxS phosphorylation also triggers 14-3-3 binding combined with changes in NPH3 phosphorylation and localisation status. Mutants of NPH3 that are unable to bind or constitutively bind 14-3-3 s show compromised functionality consistent with a model where phototropic curvature is established by signalling outputs arising from a gradient of NPH3 RxS phosphorylation across the stem. Our findings therefore establish that NPH3/RPT2-Like (NRL) proteins are phosphorylation targets for plant AGC kinases. Moreover, RxS phosphorylation is conserved in other members of the NRL family, suggesting a common mechanism of regulating plant growth to the prevailing light environment.

scholarly journals Regulation of Plant Phototropic Growth by NPH3/RPT2-like Substrate Phosphorylation and 14-3-3 Binding

2021 ◽  
Author(s):  
Stuart Sullivan ◽  
Thomas Waksman ◽  
Louise Henderson ◽  
Dimitra Paliogianni ◽  
Melanie Lütkemeyer ◽  
...  
Keyword(s):  
Consensus Sequence ◽  
Phosphorylation Site ◽  
Common Mechanism ◽  
Binding Motif ◽  
Growth Responses ◽  
Directional Growth ◽  
Agc Kinases ◽  
C Terminus

Polarity underlies all plant physiology and directional growth responses such as phototropism. Yet, our understanding of how plant tropic responses are established is far from complete. The plasma-membrane associated BTB-containing protein, NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key determinant of phototropic growth which is regulated by AGC kinases known as the phototropins (phots). However, the mechanism by which phots initiate phototropic signalling via NPH3, and other NPH3/RPT2-like (NRL) members, has remained unresolved. Here we demonstrate that NPH3 is directly phosphorylated by phot1 both in vitro and in vivo. Light-dependent phosphorylation within a conserved consensus sequence (RxS) located at the extreme C-terminus of NPH3 is necessary to promote its functionality for phototropism and petiole positioning in Arabidopsis. Phosphorylation of this region by phot1 also triggers 14-3-3 binding combined with changes in NPH3 phosphorylation and localisation status. Seedlings expressing mutants of NPH3 that are unable to bind or constitutively bind 14-3-3s show compromised functionality that is consistent with a model where signalling outputs arising from a gradient in NPH3 RxS phosphorylation/localisation across the stem are a major contributor to phototropic responsiveness. Our current findings provide further evidence that 14-3-3 proteins are instrumental components regulating auxin-dependent growth and show for the first time that NRL proteins are direct phosphorylation targets for plant AGC kinases. Moreover, the C-terminal phosphorylation site/14-3-3-binding motif of NPH3 is conserved in several members of the NRL family, suggesting a common mechanism of regulation.

Superior Stable and High Quantum Yield Phosphor Na2BaSr(PO4)2: Eu2+ for Plant Growth LEDs

2021 ◽  
Author(s):  
Jinmeng Xiang ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
Minkun Jin ◽  
Xue Zhou ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Plant Growth ◽  
Light Emitting Diodes ◽  
Light Environment ◽  
High Quantum Yield ◽  
Light Emitting ◽  
Growth Rhythm ◽  
High Quantum ◽  
Violet Light ◽  
Important Means

Controlling the light environment of plant growth using phosphor-converted light-emitting diodes (pc-LEDs) is an important means to regulate the growth rhythm and enhance the yield, in which bluish violet light...

scholarly journals A Meta-Analytical Approach on Arbuscular Mycorrhizal Fungi Inoculation Efficiency on Plant Growth and Nutrient Uptake

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 370
Author(s):  
Murugesan Chandrasekaran
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Nutrient Uptake ◽  
Mycorrhizal Fungi ◽  
Host Plants ◽  
Plant Biomass ◽  
Meta Analysis ◽  
Arbuscular Mycorrhizal ◽  
Growth Responses ◽  
Mycorrhizal Plants

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts of higher plants which increase the growth and nutrient uptake of host plants. The primary objective was initiated based on analyzing the enormity of optimal effects upon AMF inoculation in a comparative bias between mycorrhizal and non-mycorrhizal plants stipulated on plant biomass and nutrient uptake. Consequently, in accomplishing the above-mentioned objective a vast literature was collected, analyzed, and evaluated to establish a weighted meta-analysis irrespective of AMF species, plant species, family and functional group, and experimental conditions in the context of beneficial effects of AMF. I found a significant increase in the shoot, root, and total biomass by 36.3%, 28.5%, and, 29.7%, respectively. Moreover, mycorrhizal plants significantly increased phosphorus, nitrogen, and potassium uptake by 36.3%, 22.1%, and 18.5%, respectively. Affirmatively upon cross-verification studies, plant growth parameters intensification was accredited to AMF (Rhizophagus fasciculatus followed by Funniliforme mosseae), plants (Triticum aestivum followed by Solanum lycopersicum), and plant functional groups (dicot, herbs, and perennial) were the additional vital important significant predictor variables of plant growth responses. Therefore, the meta-analysis concluded that the emancipated prominent root characteristics, increased morphological traits that eventually help the host plants for efficient phosphorus uptake, thereby enhancing plant biomass. The present analysis can be rationalized for any plant stress and assessment of any microbial agent that contributes to plant growth promotion.

Growth responses of Leymus chinensis (Trin.) Tzvelev to sheep saliva after defoliation

2010 ◽  
Vol 32 (4) ◽  
pp. 419 ◽  
Author(s):  
Xing Teng ◽  
Lei Ba ◽  
Deli Wang ◽  
Ling Wang ◽  
Jushan Liu
Keyword(s):  
Plant Growth ◽  
Aboveground Biomass ◽  
Field Experiments ◽  
Perennial Grass ◽  
Leaf Length ◽  
Leymus Chinensis ◽  
Growth Responses ◽  
Time Duration ◽  
Positive Effects ◽  
Leaf Weight

Many studies indicated that saliva from herbivores might be involved in plant growth responses when plants have been grazed. However, there is currently no general agreement on whether saliva can affect plant growth. Our aims were to determine the growth response of plants to sheep saliva after defoliation under diverse environmental conditions (different sward structures), and whether the effect of saliva is influenced by time (duration) after its application. We conducted field experiments with clipping treatments and the application of sheep saliva to the damaged parts of tillers to simulate sheep grazing on the perennial grass Leymus chinensis (Trin.) Tzvelev during the early growing seasons. Results demonstrated that clipping with saliva application significantly increased tiller numbers 8 weeks after treatments in comparison with clipping alone. A key finding is that the effect of sheep saliva on plant growth was short-lived. Clipping with saliva application increased leaf weight in the second week, while clipping alone had no effect. Moreover, clipping with saliva application promoted the elongation of new leaves (not the old ones) in the first week whereas clipping alone was ineffective. Results also showed that there were no differences between clipping with saliva application and clipping alone for relative height growth rate and aboveground biomass. Therefore, we concluded that saliva application to clipping treatment would produce an additional effect compared to clipping alone for the plant and the positive effects are time dependent. The additional effects primarily embodied in the individual level of plant, such as the changes of leaf weight and leaf length. Beyond the level, the effects of saliva only produced many more tiller numbers rather than the accumulation of aboveground biomass.

Plant Growth Responses

1964 ◽  
pp. 183-195
Author(s):  
R. P. Mericle ◽  
L. W. Mericle ◽  
A. E. Smith ◽  
W. F. Campbell ◽  
D. J. Montgomery
Keyword(s):  
Plant Growth ◽  
Growth Responses

scholarly journals An Internal Polarity Landmark Is Important for Externally Induced Hyphal Behaviors in Candida albicans

2008 ◽  
Vol 7 (4) ◽  
pp. 712-720 ◽  
Author(s):  
Alexandra Brand ◽  
Anjalee Vacharaksa ◽  
Catherine Bendel ◽  
Jennifer Norton ◽  
Paula Haynes ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Kidney Tissue ◽  
Systemic Infection ◽  
Cell Cortex ◽  
Environmental Cues ◽  
Growth Responses ◽  
Directional Growth ◽  
Internal Polarity ◽  
Hyphal Tip

ABSTRACT Directional growth is a function of polarized cells such as neurites, pollen tubes, and fungal hyphae. Correct orientation of the extending cell tip depends on signaling pathways and effectors that mediate asymmetric responses to specific environmental cues. In the hyphal form of the eukaryotic fungal pathogen Candida albicans, these responses include thigmotropism and galvanotropism (hyphal turning in response to changes in substrate topography and imposed electrical fields, respectively) and penetration into semisolid substrates. During vegetative growth in C. albicans, as in the model yeast Saccharomyces cerevisiae, the Ras-like GTPase Rsr1 mediates internal cellular cues to position new buds in a prespecified pattern on the mother cell cortex. Here, we demonstrate that Rsr1 is also important for hyphal tip orientation in response to the external environmental cues that induce thigmotropic and galvanotropic growth. In addition, Rsr1 is involved in hyphal interactions with epithelial cells in vitro and its deletion diminishes the hyphal invasion of kidney tissue during systemic infection. Thus, Rsr1, an internal polarity landmark in yeast, is also involved in polarized growth responses to asymmetric environmental signals, a paradigm that is different from that described for the homologous protein in S. cerevisiae. Rsr1 may thereby contribute to the pathogenesis of C. albicans infections by influencing hyphal tip responses triggered by interaction with host tissues.

scholarly journals The PH Domain and the Polybasic c Domain of Cytohesin-1 Cooperate specifically in Plasma Membrane Association and Cellular Function

1998 ◽  
Vol 9 (8) ◽  
pp. 1981-1994 ◽  
Author(s):  
Wolfgang Nagel ◽  
Pierre Schilcher ◽  
Lutz Zeitlmann ◽  
Waldemar Kolanus
Keyword(s):  
Plasma Membrane ◽  
Cell Adhesion ◽  
Tyrosine Kinase ◽  
Biological Function ◽  
Common Mechanism ◽  
Membrane Association ◽  
Bruton’S Tyrosine Kinase ◽  
Ph Domain ◽  
Bruton's Tyrosine Kinase ◽  
Ph Domains

Recruitment of intracellular proteins to the plasma membrane is a commonly found requirement for the initiation of signal transduction events. The recently discovered pleckstrin homology (PH) domain, a structurally conserved element found in ∼100 signaling proteins, has been implicated in this function, because some PH domains have been described to be involved in plasma membrane association. Furthermore, several PH domains bind to the phosphoinositides phosphatidylinositol-(4,5)-bisphosphate and phosphatidylinositol-(3,4,5)-trisphosphate in vitro, however, mostly with low affinity. It is unclear how such weak interactions can be responsible for observed membrane binding in vivo as well as the resulting biological phenomena. Here, we investigate the structural and functional requirements for membrane association of cytohesin-1, a recently discovered regulatory protein of T cell adhesion. We demonstrate that both the PH domain and the adjacent carboxyl-terminal polybasic sequence of cytohesin-1 (c domain) are necessary for plasma membrane association and biological function, namely interference with Jurkat cell adhesion to intercellular adhesion molecule 1. Biosensor measurements revealed that phosphatidylinositol-(3,4,5)-trisphosphate binds to the PH domain and c domain together with high affinity (100 nM), whereas the isolated PH domain has a substantially lower affinity (2–3 μM). The cooperativity of both elements appears specific, because a chimeric protein, consisting of the c domain of cytohesin-1 and the PH domain of the β-adrenergic receptor kinase does not associate with membranes, nor does it inhibit adhesion. Moreover, replacement of the c domain of cytohesin-1 with a palmitoylation–isoprenylation motif partially restored the biological function, but the specific targeting to the plasma membrane was not retained. Thus we conclude that two elements of cytohesin-1, the PH domain and the c domain, are required and sufficient for membrane association. This appears to be a common mechanism for plasma membrane targeting of PH domains, because we observed a similar functional cooperativity of the PH domain of Bruton’s tyrosine kinase with the adjacent Bruton’s tyrosine kinase motif, a novel zinc-containing fold.

scholarly journals Plasma membrane damage causes NLRP3 activation and pyroptosis during Mycobacterium tuberculosis infection

2019 ◽  
Author(s):  
Kai S. Beckwith ◽  
Marianne S. Beckwith ◽  
Sindre Ullmann ◽  
Ragnhild Sætra ◽  
Haelin Kim ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Plasma Membrane ◽  
Membrane Damage ◽  
Common Mechanism ◽  
Mycobacterium Tuberculosis Infection ◽  
Plasma Membrane Damage ◽  
Cytosolic Side ◽  
Infected Cells ◽  
Mediated Contact ◽  
Spread Of Infection

AbstractMycobacterium tuberculosis (Mtb) is a major global health problem and causes extensive cytotoxicity in patient cells and tissues. Here we define an NLRP3, caspase-1 and gasdermin D-mediated pathway to pyroptosis in human monocytes following exposure to Mtb. We demonstrate an ESX-1 mediated, contact-induced plasma membrane (PM) damage response that occurs during phagocytosis or from the cytosolic side of the PM after phagosomal rupture in Mtb infected cells. This PM injury in turn causes K+ efflux and activation of NLRP3 dependent IL-1β release and pyroptosis, facilitating the spread of Mtb to neighbouring cells. Further we reveal a dynamic interplay of pyroptosis with ESCRT-mediated PM repair. Collectively, these findings reveal a novel mechanism for pyroptosis and spread of infection acting through dual PM disturbances both during and after phagocytosis. We also highlight dual PM damage as a common mechanism utilized by other NLRP3 activators that have previously been shown to act through lysosomal damage.Graphical abstract

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