Much of plant development depends on cell-to-cell redistribution of the plant hormone auxin, which is facilitated by the plasma membrane (PM) localized PIN FORMED (PIN) proteins. Auxin export activity, developmental roles, subcellular trafficking, and polarity of PINs have been well studied, but their structure remains elusive besides a rough outline that they contain two groups of 5 alpha-helices connected by a large hydrophilic loop (HL). Here, we focus on the PIN1 HL as we could produce it in sufficient quantities for biochemical investigations to provide insights into its secondary structure. Circular dichroism (CD) studies revealed its nature as an intrinsically disordered protein (IDP), manifested by the increase of structure content upon thermal melting. Consistent with IDPs serving as interaction platforms, PIN1 loops homodimerize. PIN1 HL cytoplasmic overexpression in Arabidopsis disrupts early endocytic trafficking of PIN1 and PIN2 and causes defects in the cotyledon vasculature formation. In summary, we demonstrate that PIN1 HL has an intrinsically disordered nature, which must be considered to gain further structural insights. Some secondary structures may form transiently during pairing with known and yet-to-be-discovered interactors.

• Klíčová slova
• PIN1, dimerization, hydrophilic hoop, intrinsic disorder, subcellular trafficking,
• MeSH
• Arabidopsis * metabolismus   MeSH
• biologický transport MeSH
• kořeny rostlin metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• membránové transportní proteiny genetika   metabolismus   MeSH
• proteiny huseníčku * genetika   metabolismus   MeSH
• vnitřně neuspořádané proteiny * genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyseliny indoloctové MeSH
• membránové transportní proteiny MeSH
• PIN1 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku * MeSH
• vnitřně neuspořádané proteiny * MeSH

The unprecedented rise in the human population has increased pressure on agriculture production. To enhance the production of crops, farmers mainly rely on the use of chemical fertilizers and pesticides, which have, undoubtedly, increased the production rate but at the cost of losing sustainability of the environment in the form of genetic erosion of indigenous varieties of crops and loss of fertile land. Therefore, farming practices need to upgrade toward the use of biological agents to maintain the sustainability of agriculture and the environment. In this context, using microbial inoculants and amino acids may present a more effective, safer, economical, and sustainable alternative means of realizing higher productivity of crops. Therefore, field experiments were performed on chickpea for two succeeding years using Rhizobium and L-methionine (at three levels, i.e., 5, 10, and 15 mg L-1) separately and in combinations. The results show that the application of Rhizobium and all the three levels of L-methionine increased the growth and yield of chickpea. There was a higher response to a lower dose of L-methionine, i.e., 5 mg L-1. It has been found that maximum grain yield (39.96 and 34.5% in the first and second years, respectively) of chickpea was obtained with the combined use of Rhizobium and L-methionine (5 mg L-1). This treatment was also the most effective in enhancing nodule number (91.6 and 58.19%), leghemoglobin (161.1 and 131.3%), and protein content (45.2 and 45%) of plants in both years. Likewise, photosynthetic pigments and seed chemical composition were significantly improved by Rhizobium inoculation. However, these effects were prominent when Rhizobium inoculation was accompanied by L-methionine. In conclusion, utilizing the potential of combined use of L-methionine and microbial inoculant could be a better approach for developing sustainable agriculture production.

• Klíčová slova
• L-methionine, PGPR, Rhizobium, chickpea, plant-microbe interaction,
• Publikační typ
• časopisecké články MeSH

Auxin regulates the transcription of auxin-responsive genes by the TIR1/AFBs-Aux/IAA-ARF signaling pathway, and in this way facilitates plant growth and development. However, rapid, nontranscriptional responses to auxin that cannot be explained by this pathway have been reported. In this review, we focus on several examples of rapid auxin responses: (1) the triggering of changes in plasma membrane potential in various plant species and tissues, (2) inhibition of root growth, which also correlates with membrane potential changes, cytosolic Ca2+ spikes, and a rise of apoplastic pH, (3) the influence on endomembrane trafficking of PIN proteins and other membrane cargoes, and (4) activation of ROPs (Rho of plants) and their downstream effectors such as the cytoskeleton or vesicle trafficking. In most cases, the signaling pathway triggering the response is poorly understood. A role for the TIR1/AFBs in rapid root growth regulation is emerging, as well as the involvement of transmembrane kinases (TMKs) in the activation of ROPs. We discuss similarities and differences among these rapid responses and focus on their physiological significance, which remains an enigma in most cases.

• MeSH
• endocytóza MeSH
• kořeny rostlin růst a vývoj   MeSH
• kyseliny indoloctové metabolismus   MeSH
• membránové potenciály MeSH
• proteiny vázající GTP metabolismus   MeSH
• receptory buněčného povrchu metabolismus   MeSH
• rostlinné proteiny metabolismus   MeSH
• rostliny metabolismus   MeSH
• vápník metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• auxin receptor, plant MeSH Prohlížeč
• kyseliny indoloctové MeSH
• proteiny vázající GTP MeSH
• receptory buněčného povrchu MeSH
• rostlinné proteiny MeSH
• vápník MeSH

• Publikační typ
• časopisecké články MeSH

Eukaryotic cells rely on the accuracy and efficiency of vesicular traffic. In plants, disturbances in vesicular trafficking are well studied in quickly dividing root meristem cells or polar growing root hairs and pollen tubes. The development of the female gametophyte, a unique haploid reproductive structure located in the ovule, has received far less attention in studies of vesicular transport. Key molecules providing the specificity of vesicle formation and its subsequent recognition and fusion with the acceptor membrane are Rab proteins. Rabs are anchored to membranes by covalently linked geranylgeranyl group(s) that are added by the Rab geranylgeranyl transferase (RGT) enzyme. Here we show that Arabidopsis plants carrying mutations in the gene encoding the β-subunit of RGT (rgtb1) exhibit severely disrupted female gametogenesis and this effect is of sporophytic origin. Mutations in rgtb1 lead to internalization of the PIN1 and PIN3 proteins from the basal membranes to vesicles in provascular cells of the funiculus. Decreased transport of auxin out of the ovule is accompanied by auxin accumulation in tissue surrounding the growing gametophyte. In addition, female gametophyte development arrests at the uni- or binuclear stage in a significant portion of the rgtb1 ovules. These observations suggest that communication between the sporophyte and the developing female gametophyte relies on Rab-dependent vesicular traffic of the PIN1 and PIN3 transporters and auxin efflux out of the ovule.

• Klíčová slova
• Arabidopsis, PIN1, PIN3, Rab, auxin transport, female gametophyte, funiculus, ovule, rab geranylgeranyl transferase,
• MeSH
• Arabidopsis * genetika   MeSH
• kyseliny indoloctové MeSH
• proteiny huseníčku * genetika   MeSH
• pylová láčka MeSH
• vajíčko rostlin genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyseliny indoloctové MeSH
• proteiny huseníčku * 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

Directional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration.

• MeSH
• Arabidopsis genetika   metabolismus   MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• hrách setý genetika   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• laktony metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin genetika   fyziologie   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• kyseliny indoloctové MeSH
• laktony MeSH
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH

Plants as non-mobile organisms constantly integrate varying environmental signals to flexibly adapt their growth and development. Local fluctuations in water and nutrient availability, sudden changes in temperature or other abiotic and biotic stresses can trigger changes in the growth of plant organs. Multiple mutually interconnected hormonal signaling cascades act as essential endogenous translators of these exogenous signals in the adaptive responses of plants. Although the molecular backbones of hormone transduction pathways have been identified, the mechanisms underlying their interactions are largely unknown. Here, using genome wide transcriptome profiling we identify an auxin and cytokinin cross-talk component; SYNERGISTIC ON AUXIN AND CYTOKININ 1 (SYAC1), whose expression in roots is strictly dependent on both of these hormonal pathways. We show that SYAC1 is a regulator of secretory pathway, whose enhanced activity interferes with deposition of cell wall components and can fine-tune organ growth and sensitivity to soil pathogens.

• MeSH
• Arabidopsis genetika   růst a vývoj   metabolismus   MeSH
• buněčná stěna chemie   metabolismus   MeSH
• cytokininy metabolismus   MeSH
• endozomy metabolismus   MeSH
• geneticky modifikované rostliny metabolismus   MeSH
• Golgiho aparát metabolismus   MeSH
• kořeny rostlin metabolismus   mikrobiologie   MeSH
• kyseliny indoloctové metabolismus   MeSH
• membránové proteiny genetika   metabolismus   MeSH
• odolnost vůči nemocem genetika   MeSH
• Plasmodiophorida patogenita   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• půda MeSH
• regulace genové exprese u rostlin genetika   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• sekreční dráha genetika   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom genetika   MeSH
• vezikulární transportní proteiny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AT2G18840 protein, Arabidopsis MeSH Prohlížeč
• AT4G30260 protein, Arabidopsis MeSH Prohlížeč
• cytokininy MeSH
• ECHIDNA protein, Arabidopsis MeSH Prohlížeč
• kyseliny indoloctové MeSH
• membránové proteiny MeSH
• proteiny huseníčku MeSH
• půda MeSH
• regulátory růstu rostlin MeSH
• SYAC1 protein, Arabidopsis MeSH Prohlížeč
• vezikulární transportní proteiny MeSH

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

Arabidopsis PIN2 protein directs transport of the phytohormone auxin from the root tip into the root elongation zone. Variation in hormone transport, which depends on a delicate interplay between PIN2 sorting to and from polar plasma membrane domains, determines root growth. By employing a constitutively degraded version of PIN2, we identify brassinolides as antagonists of PIN2 endocytosis. This response does not require de novo protein synthesis, but involves early events in canonical brassinolide signaling. Brassinolide-controlled adjustments in PIN2 sorting and intracellular distribution governs formation of a lateral PIN2 gradient in gravistimulated roots, coinciding with adjustments in auxin signaling and directional root growth. Strikingly, simulations indicate that PIN2 gradient formation is no prerequisite for root bending but rather dampens asymmetric auxin flow and signaling. Crosstalk between brassinolide signaling and endocytic PIN2 sorting, thus, appears essential for determining the rate of gravity-induced root curvature via attenuation of differential cell elongation.

• MeSH
• Arabidopsis účinky léků   metabolismus   MeSH
• biologický transport účinky léků   MeSH
• brassinosteroidy metabolismus   farmakologie   MeSH
• endocytóza účinky léků   MeSH
• gravitropismus účinky léků   fyziologie   MeSH
• kořeny rostlin účinky léků   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• meristém účinky léků   metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• regulátory růstu rostlin metabolismus   farmakologie   MeSH
• signální transdukce MeSH
• steroidy heterocyklické metabolismus   farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• brassinolide MeSH Prohlížeč
• brassinosteroidy MeSH
• kyseliny indoloctové MeSH
• PIN2 protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH
• steroidy heterocyklické MeSH