The pRC system is an efficient tool for genetic studies in
, ensuring direct insertion of foreign gene elements into
chromosome downstream of
. This system is designed for double recombination across
...and the downstream region, which considerably simplifies genetic studies of complementation, overexpression, pathogenicity, and in-vivo promoter activity assays with monocopy in
, one of the most destructive plant-pathogenic bacteria worldwide.
is extremely heterogeneous and is currently referred to as a
species complex (RSSC). The
gene is greatly conserved, but its downstream regions are mostly different in the RSSC, which limits the application of the current pRC plasmid in the RSSC. We compared all existing 132 genome sequences in a precise genomic
downstream region and confirmed that the pRC system is appropriate for application of chromosomal integration in all RSSC strains but needs respective reconstruction on current pRC plasmids, since
downstream regions are greatly variable in the RSSC. RSSC strains can be grouped according to identical
downstream regions. This grouping provides valuable information for gene insertion in this chromosomal region, as it facilitates universal application of the pRC system in RSSC strains.
This paper analyzes the robustness and stability of a disturbance observer (DOB) and a reaction torque observer (RTOB)-based robust motion control systems. Conventionally, a DOB is analyzed by using ...an ideal velocity measurement that is obtained without using a low-pass filter (LPF); however, it is impractical due to noise constraints. An LPF of velocity measurement changes the robustness of a DOB significantly and puts a new design constraint on the bandwidth of a DOB. An RTOB, which is used to estimate environmental impedance, is an application of a DOB. The stability of an RTOB-based robust force control system has not been reported yet since its oversimplified model is derived by assuming that an RTOB has a feedforward control structure. However, in reality, it has a feedback control structure; therefore, not only the performance but also the stability is affected by the design parameters of an RTOB. A new practical stability analysis method is proposed for an RTOB-based robust force control system. In addition to that, novel and practical design methods, which improve the robustness of a DOB and the stability and performance of an RTOB-based robust force control system, are proposed by using the new analysis methods. The validity of the proposals is verified by simulation and experimental results.
This paper analyzes a disturbance observer with a focus on parameter variations. The parameter variations are the inertia variation and the variation of torque coefficient. Conventionally, their ...nominal values are designed not as control parameters but the same values as the actual ones. However, disturbance observer is able to include the effect of phase compensation by properly selecting the nominal model parameters. In this paper, these nominal model parameters are actively designed to achieve the phase compensation. This paper proposes the design method of observer to achieve phase compensation based on disturbance observer. Compared with implementing phase compensator, the control system is simple and easy to design. The selection of these parameters has some restriction. When the nominal model parameters are much separated from the actual ones, the stability of the control system deteriorates. This paper focuses on the inertia variation and neglects the variation of torque coefficient. Furthermore, the stability of position and force control systems is analyzed. The validity of the proposed design method and the effect of phase compensation are verified by some experimental results.
The structure of food webs and carbon flow in aquatic ecosystems can be better understood by studying contributing factors such as the diets of herbivorous fish. Metabarcoding using a high-throughput ...sequencer has recently been used to clarify prey organisms of various fish except herbivorous fish. Since sequences of predator fish have dominated in sequences obtained by metabarcoding, we investigated a method for suppressing the amplification of fish DNA by using a blocking primer or peptide nucleic acid (PNA) clamp to determine the prey organisms of herbivorous fish. We designed three blocking primers and one PNA clamp that anneal to fish-specific sequences and examined how efficient they were in suppressing DNA amplification in various herbivorous fish. The results showed that the PNA clamp completely suppressed fish DNA amplification, and one of the blocking primers suppressed fish DNA amplification but less efficiently than the PNA clamp. Finally, we conducted metabarcoding using mock community samples as templates to determine whether the blocking primer or the PNA clamp was effective in suppressing fish DNA amplification. The results showed that the PNA clamp suppressed 99.3%-99.9% of fish DNA amplification, whereas the blocking primer suppressed 3.3%-32.9%. Therefore, we propose the application of the PNA clamp for clarifying the prey organisms and food preferences of various herbivorous fish.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Phospholipid signaling plays an important role in plant immune responses against phytopathogenic bacteria in Nicotiana benthamiana. Here, we isolated two phospholipase C2 (PLC2) orthologs in the N. ...benthamiana genome, designated as PLC2-1 and 2-2. Both NbPLC2-1 and NbPLC2-2 were expressed in most tissues and were induced by infiltration with bacteria and flg22. NbPLC2-1 and NbPLC2-2 (NbPLC2s) double-silenced plants showed a moderately reduced growth phenotype. The induction of the hypersensitive response was not affected, but bacterial growth and the appearance of bacterial wilt were accelerated in NbPLC2s-silenced plants when they were challenged with a virulent strain of Ralstonia solanacearum that was compatible with N. benthamiana. NbPLC2s-silenced plants showed reduced expression levels of NbPR-4, a marker gene for jasmonic acid signaling, and decreased jasmonic acid and jasmonoyl-L-isoleucine contents after inoculation with R. solanacearum. The induction of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes was reduced in NbPLC2s-silenced plants after infiltration with R. solanacearum or Pseudomonas fluorescens. Accordingly, the resistance induced by flg22 was compromised in NbPLC2s-silenced plants. In addition, the expression of flg22-induced PTI marker genes, the oxidative burst, stomatal closure, and callose deposition were all reduced in the silenced plants. Thus, NbPLC2s might have important roles in pre- and post-invasive defenses, namely in the induction of PTI.
A soil-borne bacterium
invading plant roots first colonizes the intercellular spaces of the root, and eventually enters xylem vessels, where it replicates at high levels leading to wilting symptoms. ...After invasion into intercellular spaces,
strain OE1-1 attaches to host cells and expression of the
genes encoding components of the type III secretion system (T3SS). OE1-1 then constructs T3SS and secrets effectors into host cells, inducing expression of the host gene encoding phosphatidic acid phosphatase. This leads to suppressing plant innate immunity. Then, OE1-1 grows on host cells, inducing quorum sensing (QS). The QS contributes to regulation of OE1-1 colonization of intercellular spaces including mushroom-type biofilm formation on host cells, leading to its virulence.
strains AW1 and K60 produce methyl 3-hydroxypalmitate (3-OH PAME) as a QS signal. The methyltransferase PhcB synthesizes 3-OH PAME. When 3-OH PAME reaches a threshold level, it increases the ability of the histidine kinase PhcS to phosphorylate the response regulator PhcR. This results in elevated levels of functional PhcA, the global virulence regulator. On the other hand, strains OE1-1 and GMI1000 produce methyl 3-hydroxymyristate (3-OH MAME) as a QS signal. Among
strains, the deduced PhcB and PhcS amino acid sequences are related to the production of QS signals.
produces aryl-furanone secondary metabolites, ralfuranones, which are extracellularly secreted and required for its virulence, dependent on the QS. Interestingly, ralfuranones affect the QS feedback loop. Taken together, integrated signaling
ralfuranones influences the QS, contributing to pathogen virulence.
Phosphatidic acid plays an important role in Nicotiana benthamiana immune responses against phytopathogenic bacteria. We analyzed the contributions of endoplasmic reticulum-derived chloroplast ...phospholipids, including phosphatidic acid, to the resistance of N. benthamiana against Ralstonia solanacearum. Here, we focused on trigalactosyldiacylglycerol 3 (TGD3) protein as a candidate required for phosphatidic acid signaling. On the basis of Arabidopsis thaliana TGD3 sequences, we identified two putative TGD3 orthologs in the N. benthamiana genome, NbTGD3-1 and NbTGD3-2. To address the role of TGD3s in plant defense responses, we created double NbTGD3-silenced plants using virus-induced gene silencing. The NbTGD3-silenced plants showed a moderately reduced growth phenotype. Bacterial growth and the appearance of bacterial wilt disease were accelerated in NbTGD3-silenced plants, compared with control plants, challenged with R. solanacearum. The NbTGD3-silenced plants showed reduced both expression of allene oxide synthase that encoded jasmonic acid biosynthetic enzyme and NbPR-4, a marker gene for jasmonic acid signaling, after inoculation with R. solanacearum. Thus, NbTGD3-mediated endoplasmic reticulum—chloroplast lipid transport might be required for jasmonic acid signaling-mediated basal disease resistance in N. benthamiana.
Phospholipid signaling plays an important role in plant immune responses. Here, we isolated two phospholipase C1 (PLC1) orthologs in the N. benthamiana genome, designated N. benthamiana PLC1-1 and ...PLC1-2 (NbPLC1-1 and NbPLC1-2). The NbPLC1-2-silenced plants showed an accelerated hypersensitive response (HR) challenged with an incompatible strain of R. solanacearum. Additionally, accelerated hypersensitive cell death was also observed in The NbPLC1-2-silenced plants by the bacterial effectors AvrA and PopA1 and oomycete INF1. Expression of NbPR-1, a marker gene for salicylic acid signaling, and NbPR-4, a marker gene for jasmonic acid signaling, was drastically increased by incompatible R. solanacearum in the NbPLC1-2-silenced plants. Although HR cell death was accelerated, the bacterial population was not reduced in the NbPLC1-2-silenced NahG plants compared to the NbPLC1-2-silenced wild type N. benthamiana plants. The hypersensitive cell death acceleration and bacterial population reduction from the NbPLC1-2 silencing was compromised by concomitant suppression of the NbPLC1-2 with NbCoi1. These results suggested that the NbPLC1-2 might act as a negative regulator for the HR in N. benthamiana. The NbPLC1-2 protein might negatively regulate both cell death and disease resistance via jasmonic acid-dependent signaling and suppress disease resistance via a salicylic acid -dependent pathway.
•The article showed the negative regulation of hypersensitive response by phosphoinositide-specific phospholipase C1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, we show that tasks can be realized by appropriate coordinate transformation. This approach, oblique coordinate control, decouples tasks. Even though a system is large, they can be ...designed by a combination of small tasks. Therefore, tasks can be regarded as reusable components. In this study, micro-macro bilateral control is achieved as a complicated task. Small objects can be manipulated as large objects in micro-macro bilateral control. However, ideal micro-macro bilateral controllers are usually derived only for single-degree-of-freedom (DOF) systems. Then, we propose a micro-macro bilateral controller for multi-DOF on the basis of oblique coordinate control. To obtain multi-DOF bilateral control, we first derive control goals as kinematic relations. This study also considers the case where scaling gains of position and force are selected in a different manner. The goals of micro-macro bilateral control are then controlled by oblique coordinate control. The validity of the proposed method is experimentally verified.
We previously revealed that the SEC14 phospholipid transfer protein from Nicotiana benthamiana (NbSEC14) has a role in plant immune responses against phytopathogenic bacteria in a hypersensitive ...response-independent manner. To characterize the role of NbSEC14 on plant immunity, we analyzed the relationship between NbSEC14 and pathogen-associated molecular pattern-triggered immunity (PTI). NbSEC14-silenced plants exhibited down-regulated expression of PTI marker genes (NbAcre31 and NbPti5) after being inoculated with Pseudomonas syringae pv. tabaci. Additionally, we observed accelerated bacterial growth and inhibited expression of PTI marker genes in NbSEC14-silenced plants infected with the hrp-deficient P. syringae pv. tabaci mutant. We used Pseudomonas fluorescens and flg22 as PTI inducers to further examine the association between NbSEC14 and the induction of PTI. The expression of PTI marker genes was compromised in NbSEC14-silenced plants infiltrated with P. fluorescens and flg22. Meanwhile, a cell death-based PTI assay indicated NbSEC14 was required for PTI. Furthermore, callose deposition and disease resistance induced by flg22 were compromised in NbSEC14-silenced plants. These results suggest that NbSEC14 may help regulate the induction of PTI.
•NbSEC14-silenced plants exhibited down-regulated expression of PTI marker genes.•Callose deposition and disease resistance induced by flg22 were compromised in NbSEC14-silenced plants.•NbSEC14 may help regulate the induction of PTI.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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