Studies on adventitious root formation in Pinus radiata : biochemical and molecular aspects.

A reliable in vitro rooting system was established for further studies on biochemical and molecular aspects during adventitious root formation in Pinus radiata hypocotyls. High root counts and rooting efficiency were observed in a medium comprising ½ strength of the Murashige & Skoog's basal medium (1962), 20 g/l sucrose, 9 mg/l IBA and solidified with 8 g/l agar. In this system, the first cell division, formation of root primordium initial (a cluster of meristematic cells), well-organized root primordium (a dome shaped structure) and root emergence were typically observed at around day 4, 7, 10 and 13, respectively. The increase of buffer soluble total proteins resulted in a peak at day 7 in the treatment with IBA (rooting treatment), but this peak was not observed in the other non-rooting treatments (including IBA+kinetin, kinetin alone and hormone-free control). Rooting related proteins were not observed using one-dimensional SDS polyacrylamide gel electrophoresis (PAGE). However, 19 proteins associated with the IBA treatment were observed by two-dimensional PAGE although their magnitudes were very small so that it was difficult to quantify them and establish them as novel proteins. Changes of peroxidase (PO), IAA-oxidase (IAA-O), amylase (Amy) and succinic dehydrogenase (SDH) activities assayed using tissue extracts were not significantly different between the rooting and the non-rooting treatments during the experiment. By contrast, the increase of polyphenol oxidase (PPO) activity was more significant at day 7 in the rooting treatment than in the other treatments. Nevertheless, histochemical localization of PO, PPO and SDH indicated that these enzymes were somehow associated with adventitious root formation. In the IBA treatment, the increase of starch content in the rooting region reached its maximum at day 4 and 7. This increase coincided with the histological observation ofaccumulation of starch grains at the sites where root primordia initiated. To identify the molecular signals that initiate adventitious root formation, subtracted cDNA library was made from IBA-treated hypocotyls following polymerase chain reaction (PCR) amplification of subtracted single strand-cDNAs. Inserts of 5 bacterial clones (Rl-72, R2-7, R2-22, R2-35 and R3-24) were digoxigenin-labelled and used to detect their corresponding transcripts using RNA dot blotting. Using RNA dot blotting analysis, Rl-72 detected an equivalent level of transcript in the hypocotyls at day 0 and day 7 in the treatments with and without IBA; whereas the other 4 clones, especially R2-7 and R2-35, detected different levels of transcripts in the hypocotyls during adventitious root initiation. Southern blotting analysis indicated that the R2-7 transcript is likely to be represented by a single gene or a member of a smaller gene family. Adventitious root formation in P. radiata was significantly improved using Agrobacterium rhizogenes. Compared with the strain A4T, strain LBA9402 was very effective in increasing rooting percentage and root number. High rooting percentages and root numbers were obtained in the trials with hypocotyl segments, intact seedlings and adventitious shoots. The findings in this research can assist further studies to shed some light on why some clonal cuttings of radiata pine root more easily than others do, and why mature cuttings are difficult for adventitious root induction

Root induction in radiata pine using Agrobacterium rhizogenes

Root induction using Agrobacterium rhizogenes was conducted in hypocotyl explants, intact seedlings, de-rooted seedling cuttings and adventitious shoots of radiata pine ( Pinus radiata D. Don). Use of two A. rhizogenes strains (A4T and LB9402), with or without application of IBA, can trigger root formation in different explants. Strain LBA9402 was more effective than A4T in increasing rooting percentage and root number. Addition of 4.4 uMIBA to the medium further enhanced rooting from the cultured hypocotyl segments inoculated with the two A. rhizogenes strains. Strain LBA9402+IBA induced in about 75% of the cultured hypocotyl segments to form roots. In contrast the controls failed to initiate roots on intact seedlings or cultured segments in presence or absence of IBA. Rooting of adventitious shoots from 3 year-old radiata pine was improved following inoculation with LBA9402, suggesting that this rooting treatment has potential to aid clonal propagation of radiata pine

Transjugular Intrahepatic Portosystemic Shunt for the Treatment of Portal Hypertension in Noncirrhotic Patients with Portal Cavernoma

Background. The purpose of this study was to evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) placement in the management of portal hypertension in noncirrhotic patients with portal cavernoma. Methods. We conducted a single institution retrospective analysis of 15 noncirrhotic patients with portal cavernoma treated with TIPS placement. 15 patients (4 women and 11 men) were evaluated via the technical success of TIPS placement, procedural complications, and follow-up shunt patency. Results. TIPS placement was technically successful in 11 out of 15 patients (73.3%). Procedure-related complications were limited to a single instance of hepatic encephalopathy in one patient. In patients with successful shunt placement, the portal pressure gradient decreased from 25.8±5.7 to 9.5±4.2 mmHg (P<0.001). TIPS dysfunction occurred in two patients during a median follow-up time of 45.2 months. Revision was not performed in one patient due to inadequate inflow. The other patient died of massive gastrointestinal bleeding in a local hospital. The remaining nine patients maintained functioning shunts through their last evaluation. Conclusions. TIPS is a safe and effective therapeutic treatment for noncirrhotic patients with symptomatic portal hypertension secondary to portal cavernoma

Identifying and decoupling many-body interactions in spin ensembles in diamond

We simulate the dynamics of varying density quasi-two-dimensional spin ensembles in solid-state systems, focusing on the nitrogen-vacancy centers in diamond. We consider the effects of various control sequences on the averaged dynamics of large ensembles of spins, under a realistic "spin-bath" environment. We reveal that spin locking is efficient for decoupling spins initialized along the driving axis, both from coherent dipolar interactions and from the external spin-bath environment, when the driving is two orders of magnitude stronger than the relevant coupling energies. Since the application of standard pulsed dynamical decoupling sequences leads to strong decoupling from the environment, while other specialized pulse sequences can decouple coherent dipolar interactions, such sequences can be used to identify the dominant interaction type. Moreover, a proper combination of pulsed decoupling sequences could lead to the suppression of both interaction types, allowing additional spin manipulations. Finally, we consider the effect of finite-width pulses on these control protocols and identify improved decoupling efficiency with increased pulse duration, resulting from the interplay of dephasing and coherent dynamics

Geo6D: Geometric Constraints Learning for 6D Pose Estimation

Numerous 6D pose estimation methods have been proposed that employ end-to-end regression to directly estimate the target pose parameters. Since the visible features of objects are implicitly influenced by their poses, the network allows inferring the pose by analyzing the differences in features in the visible region. However, due to the unpredictable and unrestricted range of pose variations, the implicitly learned visible feature-pose constraints are insufficiently covered by the training samples, making the network vulnerable to unseen object poses. To tackle these challenges, we proposed a novel geometric constraints learning approach called Geo6D for direct regression 6D pose estimation methods. It introduces a pose transformation formula expressed in relative offset representation, which is leveraged as geometric constraints to reconstruct the input and output targets of the network. These reconstructed data enable the network to estimate the pose based on explicit geometric constraints and relative offset representation mitigates the issue of the pose distribution gap. Extensive experimental results show that when equipped with Geo6D, the direct 6D methods achieve state-of-the-art performance on multiple datasets and demonstrate significant effectiveness, even with only 10% amount of data

Optical Multipath RF Self-Interference Cancellation Based on Phase Modulation for Full-Duplex Communication

Optical multipath RF self-interference cancellation (SIC) based on phase modulation for full-duplex communication is proposed and demonstrated experimentally. Phase modulation is utilized to convert the RF signal into optical domain, in which the time delay tuning, amplitude tuning and phase inversion for multipath RF SIC are completed. The comprehensive theoretical model of the optical multipath RF SIC system is established, and the factors affecting SIC performance including the time delay, amplitude and phase deviations are analyzed. The experimental results verify the feasibility of the proposed scheme for full-duplex communication with the cancellation depth of 26 dB and 28 dB over 100 MHz at central frequency of 6 GHz and 10 GHz, respectively. A figure of merit of the maximum interference to signal of interest ratio is defined to characterize the SOI recovery capability of optical RF SIC system

High-efficiency green management of potato late blight by a self-assembled multicomponent nano-bioprotectant

Abstract Potato late blight caused by Phytophthora infestans is a devastating disease worldwide. Unlike other plant pathogens, double-stranded RNA (dsRNA) is poorly taken up by P. infestans, which is a key obstacle in using dsRNA for disease control. Here, a self-assembled multicomponent nano-bioprotectant for potato late blight management is designed based on dsRNA and a plant elicitor. Nanotechnology overcomes the dsRNA delivery bottleneck for P. infestans and extends the RNAi protective window. The protective effect of nano-enabled dsRNA against infection arises from a synergistic mechanism that bolsters the stability of dsRNA and optimizes its effective intracellular delivery. Additionally, the nano-enabled elicitor enhances endocytosis and amplifies the systemic defense response of the plants. Co-delivery of dsRNA and an elicitor provides a protective effect via the two aspects of pathogen inhibition and elevated plant defense mechanisms. The multicomponent nano-bioprotectant exhibits superior control efficacy compared to a commercial synthetic pesticide in field conditions. This work proposes an eco-friendly strategy to manage devastating plant diseases and pests

Differential Effects of Tautomycetin and Its Derivatives on Protein Phosphatase Inhibition, Immunosuppressive Function and Antitumor Activity

In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured in vivo phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its in vivo PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions