N-terminal acetylation orchestrates glycolate-mediated ROS homeostasis to promote rice thermoresponsive growth.

Climate warming poses a significant threat to global crop production and food security. However, our understanding of the molecular mechanisms governing thermoresponsive development in crops remains limited. Here we report that the auxiliary subunit of N-terminal acetyltransferase A (NatA) in rice OsNAA15 is a prerequisite for rice thermoresponsive growth. OsNAA15 produces two isoforms OsNAA15.1 and OsNAA15.2, via temperature-dependent alternative splicing. Among the two, OsNAA15.1 is more likely to form a stable and functional NatA complex with the potential catalytic subunit OsNAA10, leading to a thermoresponsive N-terminal acetylome. Intriguingly, while OsNAA15.1 promotes plant growth under elevated temperatures, OsNAA15.2 exhibits an inhibitory effect. We identified two glycolate oxidases (GLO1/5) as major substrates from the thermoresponsive acetylome. These enzymes are involved in hydrogen peroxide (H2O2) biosynthesis via glycolate oxidation. N-terminally acetylated GLO1/5 undergo their degradation through the ubiquitin-proteasome system. This leads to reduced reactive oxygen species (ROS) production, thereby promoting plant growth, particularly under high ambient temperatures. Conclusively, our findings highlight the pivotal role of N-terminal acetylation in orchestrating the glycolate-mediated ROS homeostasis to facilitate thermoresponsive growth in rice.

Platelet bioenergetic profiling uncovers a metabolic pattern of high dependency on mitochondrial fatty acid oxidation in type 2 diabetic patients who developed in-stent restenosis.

Although platelet bioenergetic dysfunction is evident early in the pathogenesis of diabetic macrovascular complications, the bioenergetic characteristics in type 2 diabetic patients who developed coronary in-stent restenosis (ISR) and their effects on platelet function remain unclear. Here, we performed platelet bioenergetic profiling to characterize the bioenergetic alterations in 28 type 2 diabetic patients with ISR compared with 28 type 2 diabetic patients without ISR (non-ISR) and 28 healthy individuals. Generally, platelets from type 2 diabetic patients with ISR exhibited a specific bioenergetic alteration characterized by high dependency on fatty acid (FA) oxidation, which subsequently induced complex III deficiency, causing decreased mitochondrial respiration, increased mitochondrial oxidant production, and low efficiency of mitochondrial ATP generation. This pattern of bioenergetic dysfunction showed close relationships with both α-granule and dense granule secretion as measured by surface P-selectin expression, ATP release, and profiles of granule cargo proteins in platelet releasates. Importantly, ex vivo reproduction of high dependency on FA oxidation by exposing non-ISR platelets to its agonist mimicked the bioenergetic dysfunction observed in ISR platelets and enhanced platelet secretion, whereas pharmaceutical inhibition of FA oxidation normalized the respiratory and redox states of ISR platelets and diminished platelet secretion. Further, causal mediation analyses identified a strong association between high dependency on FA oxidation and increased angiographical severity of ISR, which was significantly mediated by the status of platelet secretion. Our findings, for the first time, uncover a pattern of bioenergetic dysfunction in ISR and enhance current understanding of the mechanistic link of high dependency on FA oxidation to platelet abnormalities in the context of diabetes.

First report of Pseudomonas cichorii causing bacterial leaf blight of pocketbook plant (Calceolaria hybrida) in Taiwan.

Pocketbook plants (Calceolaria spp.) are flowering ornamentals often grown as potted plants (Poesch 1937). In December 2022, leaf blight symptoms were observed on 2-mo-old plants of C. hybrida F1 'Dainty'. The disease was found in a nursery in Ren'ai Township, Nantou, and about 20% of the plants exhibited symptoms. Symptomatic plants had brown or gray necrotic lesions of different sizes and shapes, mostly around leaf margins. Lower leaf wilting was also observed (Fig. S1, A and B). Three plants were sampled. Leaf lesions were surface-disinfected with 75% ethanol and cut into smaller pieces in 10 mM MgCl2. After observing bacterial streaming under a microscope, the bacteria were streaked onto nutrient agar (NA). Following 2 days at 28°C, a type of round, creamy white colony predominated on all the plates. Three strains (Calc-A, Calc-B, and Calc-C) were obtained, one from each plant. The strains produced fluorescent pigments on King's B medium and were tested Gram-negative. The strains were characterized with the LOPAT scheme (Schaad et al. 2001). They did not exhibit activities of pectic enzymes, arginine dihydrolase and levan sucrase, but produced oxidase and induced the hypersensitive response in tobacco. DNA was extracted from the strains for PCR amplification of the 16S rDNA with primer pair 27f/1492r as described by Lane (1991). The 16S rDNA sequences were compared with entries in the GenBank database. The sequences obtained (GenBank accession no. OR824302) matched that of Pseudomonas cichorii MAFF 301158 (accession no. AB724288; 1,403/1,403 bp) and were 99% identical to that of DSM 50259T (accession no. CP074349; 1,391/1,405 bp). The strains were also tested with the species-specific primers hrp1a and hrp2a (Cottyn et al. 2011). The amplicons were sequenced and a BLASTn search showed that the sequences (accession no. OR827305) shared the highest identity (99.3%) with that of P. cichorii strain 83-1 (accession no. DQ168848; 848/854 bp) and were 97.3% identical to the sequence of DSM 50259T (accession no. CP074349; 831/854 bp). Calc-A was selected as a representative strain and deposited in the Bioresource Collection and Research Center, Taiwan (reference no. BCRC 81432). Koch's postulates were fulfilled by spray-inoculating a suspension of Calc-A on three 2-mo-old C. hybrida F1 'Dainty' plants. The inoculum was prepared by suspending NA-grown cells in 10 mM MgCl2 including 0.02% Silwet L-77 (OD600 = 0.3; 1.5 x 108 CFU/ml). For the controls, three plants were sprayed with bacteria-free solution. The plants were bagged throughout the experiment and kept in a growth chamber (14/10 h light/dark; 26/24°C day/night). Leaf blight and wilting symptoms developed on all leaves of the inoculated plants after 30 h, but not the controls (Fig. S1, C and D). The pathogen was reisolated from the treatment group, and colony PCR with hrp1a/hrp2a showed that the reisolated strain shared the same sequence with Calc-A to Calc-C. Repeating the inoculation assay produced consistent results. This is the first report of P. cichorii affecting Calceolaria in Taiwan. The bacterium has been reported infecting diverse crops in Taiwan, such as tomato and lettuce (Tsai et al. 2014). Expanding the understanding of the pathogen's potential hosts could help prevent its spread across important crops.

Influence of adjuvant chemotherapy on survival for patients with completely resected high-risk stage IB NSCLC.

BACKGROUND: The use of adjuvant chemotherapy (ACT) in completely resected stage IB NSCLC is still controversial. This study aims to investigate the efficacy of ACT in pathological stage IB non-small cell lung cancer (NSCLC) with high risk factors. METHODS: Patients with pT2aN0M0 stage IB NSCLC who underwent complete resection from 2013 to 2017 were retrospectively analyzed. Univariate and multivariable logistic regression analysis was used to assess potential independent risk factors associated with poor prognosis. To compare survival between patients who received ACT and those who did not. RESULTS: In univariate and multivariate analyses, adenocarcinomas with predominantly micropapillary (MIP) and solid patterns (SOL), poorly differentiated squamous cell carcinoma (SCC), number of lymph nodes dissected less than 16 and tumor size larger than 36 mm were identified as high-risk factors for recurrence. In patients with high risk factors for recurrence, ACT resulted in significantly longer DFS (HR, 0.4689, 95%CI, 1.193-3.818; p = 0.0108) and OS (HR, 0.4696, 95%CI, 0.6578-6.895; p = 0.2073), although OS failed to reach statistically significance. After propensity score matching (PSM), 67 pairs of patients were 1:1 matched in the two groups and all baseline characteristics were well balanced. The results also demonstrated that ACT was associated with improved DFS (HR, 0.4776, 95%CI, 0.9779-4.484; p = 0.0440) while OS was not significantly different (92.5% vs. 91.0%; HR, 0.6167, 95%CI, 0.1688-2.038; p = 0.7458). In patients with low-risk factors for recurrence, DFS (HR, 0.4831, 95%CI, 0.03025-7.715; p = 0.6068) and OS (HR, 0.969, 95%CI, 0.08364-11.21; p = 0.9794) was not significantly different between those who received ACT and those who did not. CONCLUSION: In patients with completely resected stage IB NSCLC, ACT can improve survival in patients with high risk for recurrence. Further large multicenter studies are needed to confirm these findings.

Upregulation of oxidative stress by triphenyl phosphate (TPhP) exposure causes antioxidant insult and apoptotic process in Epithelioma papulosum cyprini (EPC) cells.

Triphenyl phosphate (TPhP) is the predominant compound of organophosphate flame retardants (OPFRs), which can elicit a toxicological effect on physiological response and tissue development of fish. In this study, we investigated the effect of TPhP exposure on cell viability, antioxidant capacities, and apoptosis in EPC cells. Current study revealed that TPhP exposure could decrease cell viability and promote intracellular oxidative stress in EPC cells. In addition, high-dose TPhP exposure could facilitate antioxidant insults and cause mitochondrial collapse in a dose-dependent manner, along with increased gene expressions involved in apoptosis and unfolded protein response (UPR). These results indicated that reactive oxygen species (ROS)-induced cytotoxic stress and cell death were involved in antioxidant insults and apoptotic activation in TPhP-exposed fish cells.

Biasing the Formation of Solution-Unstable Intermediates in Coordination Self-Assembly by Mechanochemistry.

Due to the reversible nature of coordination bonds and solvation effect, coordination self-assembly pathways are often difficult to elucidate experimentally in solution, as intermediates and products are in constant equilibration. The present study shows that some of these transient and high-energy self-assembly intermediates can be accessed by means of ball-milling approaches. Among them, highly aqueous-unstable Pd3 L11 and Pd6 L14 open-cage intermediates of the framed Fujita Pd6 L14 cage and Pd2 L22 , Pd3 L21 and Pd4 L22 intermediates of Mukherjee Pd6 L24 capsule are successfully trapped in solid-state, where Pd=tmedaPd2+ , L1=2,4,6-tris(4-pyridyl)-1,3,5-triazine and L2=1,3,5-tris(1-imidazolyl)benzene). Their structures are assigned by a combination of solution-based characterization tools such as standard NMR spectroscopy, DOSY NMR, ESI-MS and X-ray diffraction. Collectively, these results highlight the opportunity of using mechanochemistry to access unique chemical space with vastly different reactivity compared to conventional solution-based supramolecular self-assembly reactions.

Ginsenosides: changing the basic hallmarks of cancer cells to achieve the purpose of treating breast cancer.

In 2021, breast cancer accounted for a substantial proportion of cancer cases and represented the second leading cause of cancer deaths among women worldwide. Although tumor cells originate from normal cells in the human body, they possess distinct biological characteristics resulting from changes in gene structure and function of cancer cells in contrast with normal cells. These distinguishing features, known as hallmarks of cancer cells, differ from those of normal cells. The hallmarks primarily include high metabolic activity, mitochondrial dysfunction, and resistance to cell death. Current evidence suggests that the fundamental hallmarks of tumor cells affect the tissue structure, function, and metabolism of tumor cells and their internal and external environment. Therefore, these fundamental hallmarks of tumor cells enable tumor cells to proliferate, invade and avoid apoptosis. Modifying these hallmarks of tumor cells represents a new and potentially promising approach to tumor treatment. The key to breast cancer treatment lies in identifying the optimal therapeutic agent with minimal toxicity to normal cells, considering the specific types of tumor cells in patients. Some herbal medicines contain active ingredients which can precisely achieve this purpose. In this review, we introduce Ginsenoside's mechanism and research significance in achieving the therapeutic effect of breast cancer by changing the functional hallmarks of tumor cells, providing a new perspective for the potential application of Ginsenoside as a therapeutic drug for breast cancer.

First filter feeding in the Early Triassic: cranial morphological convergence between Hupehsuchus and baleen whales.

Modern baleen whales are unique as large-sized filter feeders, but their roles were replicated much earlier by diverse marine reptiles of the Mesozoic. Here, we investigate convergence in skull morphology between modern baleen whales and one of the earliest marine reptiles, the basal ichthyosauromorph Hupehsuchus nanchangensis, from the Early Triassic, a time of rapid recovery of life following profound mass extinction. Two new specimens reveal the skull morphology especially in dorsal view. The snout of Hupehsuchus is highly convergent with modern baleen whales, as shown in a morphometric analysis including 130 modern aquatic amniotes. Convergences in the snout include the unfused upper jaw, specialized intermediate space in the divided premaxilla and grooves around the labial margin. Hupehsuchus had enlarged its buccal cavity to enable efficient filter feeding and probably used soft tissues like baleen to expel the water from the oral cavity. Coordinated with the rigid trunk and pachyostotic ribs suggests low speeds of aquatic locomotion, Hupehsuchus probably employed continuous ram filter feeding as in extant bowhead and right whales. The Early Triassic palaeoenvironment of a restrictive lagoon with low productivity drove Hupehsuchus to feed on zooplankton, which facilitated ecosystem recovery in the Nanzhang-Yuan'an Fauna at the beginning of the Mesozoic.

Biasing Divergent Polycyclic Aromatic Hydrocarbon Oxidation Pathway by Solvent-Free Mechanochemistry.

Precise control in reaction selectivity is the goal in modern organic synthesis, and it has been widely studied throughout the synthetic community. In comparison, control of divergent reactivity of a given reagent under different reaction conditions is relatively less explored aspect of chemical selectivity. We herein report an unusual reaction between polycyclic aromatic hydrocarbons and periodic acid H5IO6 (1), where the product outcome is dictated by the choice of reaction conditions. That is, reactions under solution-based condition give preferentially C-H iodination products, while reactions under solvent-free mechanochemical condition provide C-H oxidation quinone products. Control experiments further indicated that the iodination product is not a reaction intermediate toward the oxidation product and vice versa. Mechanistic studies unveiled an in situ crystalline-to-crystalline phase change in 2 during ball-milling treatment, where we assigned it as a polymeric hydrogen-bond network of 1. We believe that this polymeric crystalline phase shields the more embedded electrophilic I═O group of 1 from C-H iodination and bias a divergent C-H oxidation pathway (with I═O) in the solid state. Collectively, this work demonstrates that mechanochemistry can be employed to completely switch a reaction pathway and unmask hidden reactivity of chemical reagents.

Infection patterns of 'Candidatus Liberibacter europaeus' in Cacopsylla oluanpiensis, a psyllid pest of Pittosporum pentandrum.

'Candidatus Liberibacter' is a genus of plant-associated bacteria that can be transmitted by insects of the superfamily Psylloidea. Since many members of this genus are putative causal agents of plant diseases, it is crucial in studying their interactions with the psyllid vectors. However, previous studies have mainly focused on few species associated with diseases of economic significance, and this may potentially hinder the development of a more comprehensive understanding of the ecology of 'Ca. Liberibacter'. The present study showed that an endemic psyllid species in Taiwan, Cacopsylla oluanpiensis, is infected with a species of 'Ca. Liberibacter'. The bacterium was present in geographically distant populations of the psyllid and was identified as 'Ca. Liberibacter europaeus' (CLeu), a species which generally does not induce plant symptoms. Analysis of CLeu infection densities in male and female C. oluanpiensis with different abdominal colors using quantitative polymerase chain reaction revealed that CLeu infection was not significantly associated with psyllid gender and body color. Instead, CLeu infection had a negative effect on the body sizes of both male and female psyllids, which is influenced by bacterial titer. Investigation on CLeu's distribution patterns in C. oluanpiensis's host plant Pittosporum pentandrum indicated that CLeu does not behave as a plant pathogen. Also, results showed that nymph-infested twigs had a greater chance of carrying high loads of CLeu, suggesting that ovipositing females and the nymphs are the main source of the bacterium in the plants. This study is not only the first to formally report the presence of CLeu in C. oluanpiensis and plants in the family Pittosporaceae, but also represents the first record of the bacterium in Taiwan. Overall, the findings in this work broaden the understanding of associations between psyllids and 'Ca. Liberibacter' in the field.

Optimal exercise to improve physical ability and performance in older adults with sarcopenia: a systematic review and network meta-analysis.

OBJECTIVE: The study aimed to pool and analyze the effects of different forms of exercise on muscle strength (handgrip strength [HGS]), and physical performance (timed up and go test [TUGT], gait speed [GS] and chair stand test [CS]) in older adults with sarcopenia. METHODS: The effect sizes of all studies retrieved and included by the four databases were analyzed using the network meta-analysis and expressed as standardized mean differences (SMD) and the corresponding 95% confidence intervals (CI). RESULTS: Twenty studies were included in this study with 1347 older adults with sarcopenia. Compared with control and other intervention groups, resistance training (RT) improved HGS [SMD=3.8, 95% CI (1.3, 6.0), p<0.05] and TUGT [SMD = -1.99, 95% CI (-2.82, -1.16), p<0.05] significantly. comprehensive training (CT) [SMD = -2.04, 95% CI (-3.05, -1.06), Pp<0.05] and Comprehensive training under self-management (CT_SM) [SMD = -2.01, 95% CI (-3.24, -0.78), p<0.05] improved TUGT significantly. CONCLUSION: In older adults with sarcopenia, RT could improve HGS and TUGT, CT and CT_SM could improve TUGT. There were no significant changes in CS and GS with any of the exercise training modes.

Prior skeleton based online deep reinforcement learning for coronary artery centerline extraction.

Coronary centerline extraction is an essential technique for X-ray coronary angiography (XCA) image analysis, which provides qualitative and quantitative guidance for percutaneous coronary intervention (PCI). In this paper, an online deep reinforcement learning method for coronary centerline extraction is proposed based on the prior vascular skeleton. Firstly, with XCA image preprocessing (foreground extraction and vessel segmentation) results, the improved ZhangSuen image thinning algorithm is used to rapidly extract the preliminary vascular skeleton network. On this basis, according to the spatial-temporal and morphological continuity of the angiography image sequence, the connectivity of different branches is determined using k-means clustering, and the vessel segments are then grouped, screened, and reconnected to obtain the aorta and its major branches. Finally, using the previous results as prior information, an online Deep Q-Network (DQN) reinforcement learning method is proposed to optimize each branch simultaneously. It comprehensively considers grayscale intensity and eigenvector continuity to achieve the combination of data-driven and model-driven without pre-training. Experimental results on clinical images and the third-party dataset demonstrate that the proposed method can accurately extract, restructure, and optimize the centerline of XCA images with a higher overall accuracy than the existing state-of-the-art methods.

[Application of "major scientific issues and engineering technology difficulties in traditional Chinese medicine(2019-2021)" in national science and t echnology layout].

In order to judge the future development trend of science and technology, plan ahead and lay out the frontier technology fields and directions, China Association of Chinese Medicine(CACM) has launched consultation projects for collecting "major scienti-fic issues and engineering technology difficulties in traditional Chinese medicine(TCM)" for the industry for three consecutive years since 2019. Up to now, 18 projects have been selected as major issues for research, and some experience and achievements have been made. These projects have been applied in important scientific and technological work such as scientific and technological planning and deployment at all levels of national, local, and scientific research institutions, the selection and cultivation of major national scientific and technological projects, and the construction of innovation bases, giving full play to the role of the think tank advisory committee of CACM. This study reviewed the selection of major issues for the first time, systematically combed its application in the national layout of science and technology, and put forward the existing problems and improvement suggestions, aiming to provide new ideas for further improving the selection of major issues and research direction, providing a theoretical basis and decision support for the national scientific and technological layout in the field of TCM, and promoting scientific and technological innovation to facilitate the high quality development of TCM.

Constructing Highly Reliable and Adaptive Primary Explosive Composites for Micro-Initiator Assisting by a Hybrid Template of Metal-Organic Frameworks and Cross-Linked Polymers.

Primary explosive, as a reliable initiator for secondary explosives, is the central component of micro-initiators for modern aerospace systems and military operations. However, they are typically prepared as powders, posing potential safety risks because of the inevitable particles scattering issues in the actual working environments. Here, the fabrication of a highly adaptive bulk material of copper azide (CA)-based safe primary explosive for micro-initiators is demonstrated. This bulk material, as derived by a complete azidation reaction of the carbonized metal-organic framework/cross-linked polymer hybrid template, enables the firm embedding of active CA species in a cross-linked carbon network (denoted as CA-C). Interestingly, this CA-C bulk material demonstrates multifarious mechanical stabilities (e.g., good shock and vibration resistance, and anti-overload capacity) in the simulated working conditions. Meanwhile, the CA contents in the CA-C bulk material reached as high as 70.3%, ensuring its detonation power. As a proof of concept, CA-C bulk material assembling in a micro-detonator can efficiently detonate the secondary explosive of CL-20 under laser irradiation. This work hereby advances the fabrication of safe and powerful primary explosives for the fulfillment of safe micro-initiator in a broad range of applications in aerospace systems.

Gut-liver immune and redox response in hybrid fish (Carassius cuvieri ♀ × Carassius auratus red var. ♂) after gut infection with Aeromonas hydrophila.

Aeromonas hydrophila can pose a great threat to fish survival. In this study, we investigated the differential immune and redox response in gut-liver axis of hybrid fish (WR) undergoing gut infection. WR anally intubated with A. hydrophila showed severe midgut injury with decreased length-to-width ratios of villi along with GC hyperplasia and enhanced antioxidant activities, but expression profiles of cytokines, chemokines, antibacterial molecules, redox sensors and tight junction proteins decreased dramatically. In contrast, immune-related gene expressions and antioxidant activities increased significantly in liver of WR following gut infection with A. hydrophila. These results highlighted the differential immune regulation and redox balance in gut-liver axis response to bacterial infection.

Bacterial Leaf Blight of Polyscias guilfoylei Caused by a Novel Pathovar of Xanthomonas euvesicatoria.

Polyscias guilfoylei is a popular ornamental belonging to the Araliaceae family. The present study identified and characterized bacterial strains causing leaf lesions on P. guilfoylei in a nursery in Taiwan. Strains Pgu1 to Pgu5 were isolated from infected leaf tissues and Koch's postulates were fulfilled. Observation of Pgu1 under a transmission electron microscope revealed that its cells were single flagellated and rod shaped. Sequencing of Pgu1 to Pgu5's 16S ribosomal DNA showed that they belong to the genus Xanthomonas. The biochemical and physiological traits of these bacteria were determined, and many of them also resemble those of other xanthomonads. However, the strains were unable to produce yellow pigments typically found in most members of the Xanthomonas genus, even when grown on yeast dextrose calcium carbonate (YDC) agar. Physiological assays and phylogenetic analyses based on multiple loci showed that the isolates were closely associated with members of the species Xanthomonas euvesicatoria and phylogenetically distant from X. hortorum pv. hederae, the currently only known xanthomonad capable of inducing diseases on Polyscias spp. Artificial inoculation into different host plants revealed that a representative strain, Pgu1, is specialized to P. guilfoylei and perhaps other members of the Araliaceae family. Based on the results from the phylogenetic and phenotypic analyses, the present work concludes that these strains belong to a novel pathovar of X. euvesicatoria. The pathovar epithet polysciadis is proposed.

MUC1 promotes glioblastoma progression and TMZ resistance by stabilizing EGFRvIII.

Epidermal growth factor receptor variant III (EGFRvIII) is a mutant isoform of EGFR with a deletion of exons 2-7 making it insensitive to EGF stimulation and downstream signal constitutive activation. However, the mechanism underlying the stability of EGFRvIII remains unclear. Based on CRISPR-Cas9 library screening, we found that mucin1 (MUC1) is essential for EGFRvIII glioma cell survival and temozolomide (TMZ) resistance. We revealed that MUC1-C was upregulated in EGFRvIII-positive cells, where it enhanced the stability of EGFRvIII. Knockdown of MUC1-C increased the colocalization of EGFRvIII and lysosomes. Upregulation of MUC1 occurred in an NF-κB dependent manner, and inhibition of the NF-κB pathway could interrupt the EGFRvIII-MUC1 feedback loop by inhibiting MUC1-C. In a previous report, we identified AC1Q3QWB (AQB), a small molecule that could inhibit the phosphorylation of NF-κB. By screening the structural analogs of AQB, we obtained EPIC-1027, which could inhibit the NF-κB pathway more effectively. EPIC-1027 disrupted the EGFRvIII-MUC1-C positive feedback loop in vitro and in vivo, inhibited glioma progression, and promoted sensitization to TMZ. In conclusion, we revealed the pivotal role of MUC1-C in stabilizing EGFRvIII in glioblastoma (GBM) and identified a small molecule, EPIC-1027, with great potential in GBM treatment.

Dual-function DEFENSIN 8 mediates phloem cadmium unloading and accumulation in rice grains.

Grain cadmium (Cd) is translocated from source to sink tissues exclusively via phloem, though the phloem Cd unloading transporter has not been identified yet. Here, we isolated and functionally characterized a defensin-like gene DEFENSIN 8 (DEF8) highly expressed in rice (Oryza sativa) grains and induced by Cd exposure in seedling roots. Histochemical analysis and subcellular localization detected DEF8 expression preferentially in pericycle cells and phloem of seedling roots, as well as in phloem of grain vasculatures. Further analysis demonstrated that DEF8 is secreted into extracellular spaces possibly by vesicle trafficking. DEF8 bound to Cd in vitro, and Cd efflux from protoplasts as well as loading into xylem vessels decreased in the def8 mutant seedlings compared with the wild type. At maturity, significantly less Cd accumulation was observed in the mutant grains. These results suggest that DEF8 is a dual function protein that facilitates Cd loading into xylem and unloading from phloem, thus mediating Cd translocation from roots to shoots and further allocation to grains, representing a phloem Cd unloading regulator. Moreover, essential mineral nutrient accumulation as well as important agronomic traits were not affected in the def8 mutants, suggesting DEF8 is an ideal target for breeding low grain Cd rice.

A one-pot electrochemical synthesis of 2-aminothiazoles from active methylene ketones and thioureas mediated by NH4I.

The electrochemical preparation of 2-aminothiazoles has been achieved by the reaction of active methylene ketones with thioureas assisted by ᴅʟ-alanine using NH4I as a redox mediator. The electrochemical protocol proceeds in an undivided cell equipped with graphite plate electrodes under constant current conditions. Various active methylene ketones, including ß-keto ester, ß-keto amide, ß-keto nitrile, ß-keto sulfone and 1,3-diketones, can be converted to the corresponding 2-aminothiazoles. Mechanistically, the in situ generated α-iodoketone was proposed to be the key active species.