Nejvíce citovaný článek - PubMed ID 11845211
The plant-signaling molecule auxin triggers fast and slow cellular responses across land plants and algae. The nuclear auxin pathway mediates gene expression and controls growth and development in land plants, but this pathway is absent from algal sister groups. Several components of rapid responses have been identified in Arabidopsis, but it is unknown if these are part of a conserved mechanism. We recently identified a fast, proteome-wide phosphorylation response to auxin. Here, we show that this response occurs across 5 land plant and algal species and converges on a core group of shared targets. We found conserved rapid physiological responses to auxin in the same species and identified rapidly accelerated fibrosarcoma (RAF)-like protein kinases as central mediators of auxin-triggered phosphorylation across species. Genetic analysis connects this kinase to both auxin-triggered protein phosphorylation and rapid cellular response, thus identifying an ancient mechanism for fast auxin responses in the green lineage.
- Klíčová slova
- RAF kinase, auxin, plant evolution, protein phosphorylation,
- MeSH
- Arabidopsis genetika metabolismus MeSH
- bílkoviny řas metabolismus MeSH
- fosforylace MeSH
- kyseliny indoloctové metabolismus MeSH
- proteinkinasy metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- rostlinné proteiny metabolismus MeSH
- rostliny metabolismus MeSH
- signální transdukce * MeSH
- vyšší rostliny * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- bílkoviny řas MeSH
- kyseliny indoloctové MeSH
- proteinkinasy MeSH
- rostlinné proteiny MeSH
Roots are sensors evolved to simultaneously respond to manifold signals, which allow the plant to survive. Root growth responses, including the modulation of directional root growth, were shown to be differently regulated when the root is exposed to a combination of exogenous stimuli compared to an individual stress trigger. Several studies pointed especially to the impact of the negative phototropic response of roots, which interferes with the adaptation of directional root growth upon additional gravitropic, halotropic or mechanical triggers. This review will provide a general overview of known cellular, molecular and signalling mechanisms involved in directional root growth regulation upon exogenous stimuli. Furthermore, we summarise recent experimental approaches to dissect which root growth responses are regulated upon which individual trigger. Finally, we provide a general overview of how to implement the knowledge gained to improve plant breeding.
- Klíčová slova
- ABA, SnRK1, SnRK2, TOR, auxin, green systems biology, metabolomics, panomics,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The phytohormone auxin is a master regulator of plant growth and development in response to many endogenous and environmental signals. The underlying coordination of growth is mediated by the formation of auxin maxima and concentration gradients. The visualization of auxin dynamics and distribution can therefore provide essential information to increase our understanding of the mechanisms by which auxin orchestrates these growth and developmental processes. Several auxin reporters have been developed to better perceive the auxin distribution and signaling machinery in vivo. This review focuses on different types of auxin reporters and biosensors used to monitor auxin distribution and its dynamics, as well as auxin signaling, at the cellular and tissue levels in different plant species. We provide a brief history of each reporter and biosensor group and explain their principles and utilities.
Mineral nutrition is one of the key environmental factors determining plant development and growth. Nitrate is the major form of macronutrient nitrogen that plants take up from the soil. Fluctuating availability or deficiency of this element severely limits plant growth and negatively affects crop production in the agricultural system. To cope with the heterogeneity of nitrate distribution in soil, plants evolved a complex regulatory mechanism that allows rapid adjustment of physiological and developmental processes to the status of this nutrient. The root, as a major exploitation organ that controls the uptake of nitrate to the plant body, acts as a regulatory hub that, according to nitrate availability, coordinates the growth and development of other plant organs. Here, we identified a regulatory framework, where cytokinin response factors (CRFs) play a central role as a molecular readout of the nitrate status in roots to guide shoot adaptive developmental response. We show that nitrate-driven activation of NLP7, a master regulator of nitrate response in plants, fine tunes biosynthesis of cytokinin in roots and its translocation to shoots where it enhances expression of CRFs. CRFs, through direct transcriptional regulation of PIN auxin transporters, promote the flow of auxin and thereby stimulate the development of shoot organs.
- Klíčová slova
- macronutrient, nitrate, plant development,
- MeSH
- cytokininy metabolismus MeSH
- dusičnany * metabolismus MeSH
- kořeny rostlin metabolismus MeSH
- kyseliny indoloctové * metabolismus MeSH
- půda MeSH
- regulace genové exprese u rostlin MeSH
- signální transdukce MeSH
- výhonky rostlin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cytokininy MeSH
- dusičnany * MeSH
- kyseliny indoloctové * MeSH
- půda MeSH
Apple species are the unique naturally rich source of dihydrochalcones, phenolic compounds with an elusive role in planta, but suggested auto-allelochemical features related to "apple replant disease" (ARD). Our aim was to elucidate the physiological basis of the phytotoxic action of dihydrochalcone phloretin in the model plant Arabidopsis and to promote phloretin as a new prospective eco-friendly phytotoxic compound. Phloretin treatment induced a significant dose-dependent growth retardation and severe morphological abnormalities and agravitropic behavior in Arabidopsis seedlings. Histological examination revealed a reduced starch content in the columella cells and a serious disturbance in root architecture, which resulted in the reduction in length of meristematic and elongation zones. Significantly disturbed auxin metabolome profile in roots with a particularly increased content of IAA accumulated in the lateral parts of the root apex, accompanied by changes in the expression of auxin biosynthetic and transport genes, especially PIN1, PIN3, PIN7, and ABCB1, indicates the role of auxin in physiological basis of phloretin-induced growth retardation. The results reveal a disturbance of auxin homeostasis as the main mechanism of phytotoxic action of phloretin. This mechanism makes phloretin a prospective candidate for an eco-friendly bioherbicide and paves the way for further research of phloretin role in ARD.
- Klíčová slova
- ARD, Malus × domestica Borkh. (apple), allelopathy, auxin, dihydrochalcones, phloretin, phytotoxicity, polar auxin transport,
- Publikační typ
- časopisecké články MeSH
Primary root growth is required by the plant to anchor in the soil and reach out for nutrients and water, while dealing with obstacles. Efficient root elongation and bending depends upon the coordinated action of environmental sensing, signal transduction, and growth responses. The actin cytoskeleton is a highly plastic network that constitutes a point of integration for environmental stimuli and hormonal pathways. In this review, we present a detailed compilation highlighting the importance of the actin cytoskeleton during primary root growth and we describe how actin-binding proteins, plant hormones, and actin-disrupting drugs affect root growth and root actin. We also discuss the feedback loop between actin and root responses to light and gravity. Actin affects cell division and elongation through the control of its own organization. We remark upon the importance of longitudinally oriented actin bundles as a hallmark of cell elongation as well as the role of the actin cytoskeleton in protein trafficking and vacuolar reshaping during this process. The actin network is shaped by a plethora of actin-binding proteins; however, there is still a large gap in connecting the molecular function of these proteins with their developmental effects. Here, we summarize their function and known effects on primary root growth with a focus on their high level of specialization. Light and gravity are key factors that help us understand root growth directionality. The response of the root to gravity relies on hormonal, particularly auxin, homeostasis, and the actin cytoskeleton. Actin is necessary for the perception of the gravity stimulus via the repositioning of sedimenting statoliths, but it is also involved in mediating the growth response via the trafficking of auxin transporters and cell elongation. Furthermore, auxin and auxin analogs can affect the composition of the actin network, indicating a potential feedback loop. Light, in its turn, affects actin organization and hence, root growth, although its precise role remains largely unknown. Recently, fundamental studies with the latest techniques have given us more in-depth knowledge of the role and organization of actin in the coordination of root growth; however, there remains a lot to discover, especially in how actin organization helps cell shaping, and therefore root growth.
- Klíčová slova
- actin, actin-binding protein, auxin, cell elongation, gravitropism, light, root growth,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
To overcome nitrogen deficiency, legume roots establish symbiotic interactions with nitrogen-fixing rhizobia that are fostered in specialized organs (nodules). Similar to other organs, nodule formation is determined by a local maximum of the phytohormone auxin at the primordium site. However, how auxin regulates nodule development remains poorly understood. Here, we found that in soybean, (Glycine max), dynamic auxin transport driven by PIN-FORMED (PIN) transporter GmPIN1 is involved in nodule primordium formation. GmPIN1 was specifically expressed in nodule primordium cells and GmPIN1 was polarly localized in these cells. Two nodulation regulators, (iso)flavonoids trigger expanded distribution of GmPIN1b to root cortical cells, and cytokinin rearranges GmPIN1b polarity. Gmpin1abc triple mutants generated with CRISPR-Cas9 showed the impaired establishment of auxin maxima in nodule meristems and aberrant divisions in the nodule primordium cells. Moreover, overexpression of GmPIN1 suppressed nodule primordium initiation. GmPIN9d, an ortholog of Arabidopsis thaliana PIN2, acts together with GmPIN1 later in nodule development to acropetally transport auxin in vascular bundles, fine-tuning the auxin supply for nodule enlargement. Our findings reveal how PIN-dependent auxin transport modulates different aspects of soybean nodule development and suggest that the establishment of auxin gradient is a prerequisite for the proper interaction between legumes and rhizobia.
- MeSH
- biologický transport MeSH
- Glycine max genetika růst a vývoj metabolismus MeSH
- kořenové hlízky rostlin růst a vývoj metabolismus MeSH
- kyseliny indoloctové metabolismus MeSH
- rostlinné proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kyseliny indoloctové MeSH
- rostlinné proteiny MeSH
Plant growth and productivity are orchestrated by a network of signaling cascades involved in balancing responses to perceived environmental changes with resource availability. Vascular plants are divided into the shoot, an aboveground organ where sugar is synthesized, and the underground located root. Continuous growth requires the generation of energy in the form of carbohydrates in the leaves upon photosynthesis and uptake of nutrients and water through root hairs. Root hair outgrowth depends on the overall condition of the plant and its energy level must be high enough to maintain root growth. TARGET OF RAPAMYCIN (TOR)-mediated signaling cascades serve as a hub to evaluate which resources are needed to respond to external stimuli and which are available to maintain proper plant adaptation. Root hair growth further requires appropriate distribution of the phytohormone auxin, which primes root hair cell fate and triggers root hair elongation. Auxin is transported in an active, directed manner by a plasma membrane located carrier. The auxin efflux carrier PIN-FORMED 2 is necessary to transport auxin to root hair cells, followed by subcellular rearrangements involved in root hair outgrowth. This review presents an overview of events upstream and downstream of PIN2 action, which are involved in root hair growth control.
- Klíčová slova
- PIN-FORMED 2, ROP2, ROS, TOR signaling, auxin, plant adaptation, polar cell elongation, root growth, root hair growth,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Spontaneously arising channels that transport the phytohormone auxin provide positional cues for self-organizing aspects of plant development such as flexible vasculature regeneration or its patterning during leaf venation. The auxin canalization hypothesis proposes a feedback between auxin signaling and transport as the underlying mechanism, but molecular players await discovery. We identified part of the machinery that routes auxin transport. The auxin-regulated receptor CAMEL (Canalization-related Auxin-regulated Malectin-type RLK) together with CANAR (Canalization-related Receptor-like kinase) interact with and phosphorylate PIN auxin transporters. camel and canar mutants are impaired in PIN1 subcellular trafficking and auxin-mediated PIN polarization, which macroscopically manifests as defects in leaf venation and vasculature regeneration after wounding. The CAMEL-CANAR receptor complex is part of the auxin feedback that coordinates polarization of individual cells during auxin canalization.
- MeSH
- Arabidopsis enzymologie genetika MeSH
- biologický transport MeSH
- kyseliny indoloctové metabolismus MeSH
- mapování interakce mezi proteiny MeSH
- membránové transportní proteiny metabolismus MeSH
- proteinkinasy genetika metabolismus MeSH
- proteiny huseníčku metabolismus MeSH
- transkripční faktory metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kyseliny indoloctové MeSH
- membránové transportní proteiny MeSH
- PIN1 protein, Arabidopsis MeSH Prohlížeč
- proteinkinasy MeSH
- proteiny huseníčku MeSH
- transkripční faktory MeSH
- WRKY23 protein, Arabidopsis MeSH Prohlížeč
Cell polarity is a fundamental feature of all multicellular organisms. PIN auxin transporters are important cell polarity markers that play crucial roles in a plethora of developmental processes in plants. Here, to identify components involved in cell polarity establishment and maintenance in plants, we performed a forward genetic screening of PIN2:PIN1-HA;pin2 Arabidopsis (Arabidopsis thaliana) plants, which ectopically express predominantly basally localized PIN1 in root epidermal cells, leading to agravitropic root growth. We identified the regulator of PIN polarity 12 (repp12) mutation, which restored gravitropic root growth and caused a switch in PIN1-HA polarity from the basal to apical side of root epidermal cells. Next Generation Sequencing and complementation experiments established the causative mutation of repp12 as a single amino acid exchange in Aminophospholipid ATPase3 (ALA3), a phospholipid flippase predicted to function in vesicle formation. repp12 and ala3 T-DNA mutants show defects in many auxin-regulated processes, asymmetric auxin distribution, and PIN trafficking. Analysis of quintuple and sextuple mutants confirmed the crucial roles of ALA proteins in regulating plant development as well as PIN trafficking and polarity. Genetic and physical interaction studies revealed that ALA3 functions together with the ADP ribosylation factor GTPase exchange factors GNOM and BIG3 in regulating PIN polarity, trafficking, and auxin-mediated development.
- MeSH
- ADP-ribosylační faktory metabolismus MeSH
- Arabidopsis účinky léků metabolismus MeSH
- biologický transport účinky léků MeSH
- brefeldin A farmakologie MeSH
- buněčná membrána účinky léků metabolismus MeSH
- genetická epistáze účinky léků MeSH
- GTP-fosfohydrolasy metabolismus MeSH
- kyseliny indoloctové metabolismus MeSH
- mutace genetika MeSH
- proteiny huseníčku metabolismus MeSH
- proteiny přenášející fosfolipidy metabolismus MeSH
- tabák metabolismus MeSH
- trans-Golgiho síť účinky léků metabolismus MeSH
- vazba proteinů účinky léků MeSH
- výměnné faktory guaninnukleotidů metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ADP-ribosylační faktory MeSH
- brefeldin A MeSH
- GTP-fosfohydrolasy MeSH
- kyseliny indoloctové MeSH
- proteiny huseníčku MeSH
- proteiny přenášející fosfolipidy MeSH
- výměnné faktory guaninnukleotidů MeSH
