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Some transporters play important roles in the uptake and acropetal xylem translocation of vectorized agrochemicals. However, it is poorly understood the basipetally phloem-loading functions of transporters toward vectorized agrochemicals. Here, L-Val-PCA (L-valine-phenazine-1-carboxylic acid conjugate) uptake was demonstrated carrier-mediated. RcAAP2, RcANT7, and RcLHT1 showed a similarly up-regulated expression pattern from 62 transporter coding genes in Ricinus at 1 h after L-Val or L-Val-PCA treatment. Subcellular localization revealed that fusion RcAAP2-eGFP, RcANT7-eGFP and RcLHT1-eGFP proteins were expressed in the plasma membrane of mesophyll and phloem cells. Yeast assays found that RcAAP2, RcANT7, and RcLHT1 facilitated L-Val-PCA uptake. To further demonstrate the phloem-loading functions, using vacuum infiltration strategy, an Agrobacterium-mediated RNA interference (RNAi) protocol was constructed in seedlings. HPLC detection indicated that L-Val-PCA phloem sap concentrations were significantly decreased 54.5 %, 27.6 %, and 41.6 % after silencing for 72 h and increased 48.3 %, 52.6 %, and 52.4 % after overexpression, respectively. In conclusion, the plasma membrane-located RcAAP2, RcANT7, and RcLHT1 can loaded L-Val-PCA into Ricinus sieve tubes for the phloem translocation, which may aid in the utilization of transporters and molecular design of phloem-mobile fungicides target root or vascular pathogens., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interests. Manuscript has been approved by all authors for submission., (Copyright © 2023 Elsevier B.V. All rights reserved.)

To effectively control the infection of plant pathogens, we designed and synthesized a series of phenylthiazole derivatives containing a 1,3,4-thiadiazole thione moiety and screened for their antibacterial potencies against Ralstonia solanacearum , Xanthomonas oryzae pv. oryzae , as well as their antifungal potencies against Sclerotinia sclerotiorum , Rhizoctonia solani , Magnaporthe oryzae and Colletotrichum gloeosporioides . The chemical structures of the target compounds were characterized by 1 H NMR, 13 C NMR and HRMS. The bioassay results revealed that all the tested compounds exhibited moderate-to-excellent antibacterial and antifungal activities against six plant pathogens. Especially, compound 5k possessed the most remarkable antibacterial activity against R. solanacearum (EC 50 = 2.23 μg/mL), which was significantly superior to that of compound E1 (EC 50 = 69.87 μg/mL) and the commercial agent Thiodiazole copper (EC 50 = 52.01 μg/mL). Meanwhile, compound 5b displayed the most excellent antifungal activity against S. sclerotiorum (EC 50 = 0.51 μg/mL), which was equivalent to that of the commercial fungicide Carbendazim (EC 50 = 0.57 μg/mL). The preliminary structure-activity relationship (SAR) results suggested that introducing an electron-withdrawing group at the meta-position and ortho-position of the benzene ring could endow the final structure with remarkable antibacterial and antifungal activity, respectively. The current results indicated that these compounds were capable of serving as promising lead compounds.

Hard and superconducting materials play significant roles in their respective application areas and are also crucial research fields in condensed matter physics. Materials with the key properties of both hard and superconducting properties could lead to technology development, but it is also full of challenges. Herein, we report the synthesis of high-quality metastable W 3 P single crystals with superconductivity and excellent mechanical properties. The synergistic effect of temperature and pressure was effective in suppressing further decomposition of metastable W 3 P as-synthesized by our synthesis technique (high-pressure and high-temperature method). The transport and magnetic measurements indicate that W 3 P is a typical type-II BCS superconductor, displaying a superconducting transition temperature of 5.9 K and an impressive critical magnetic field of 4.35 T. Theory calculations reveal a metallic property in W 3 P, and the phonon modes of the vibration of W atoms are important for electron-phonon interaction. Meanwhile, W 3 P shows excellent mechanical properties with a high fracture toughness of 8 MPa m 1/2 and an impressive asymptotic hardness of 22 GPa, which is currently reported as being the hardest among transition metal phosphides. It opens up a new class of advanced materials that combine excellent mechanical properties with superconductivity.

Objectives: To determine whether 3D-CT multi-level anatomical features can provide a more accurate prediction of surgical decision-making for partial or radical nephrectomy in renal cell carcinoma., Methods: This is a retrospective study based on multi-center cohorts. A total of 473 participants with pathologically proved renal cell carcinoma were split into the internal training and the external testing set. The training set contains 412 cases from five open-source cohorts and two local hospitals. The external testing set includes 61 participants from another local hospital. The proposed automatic analytic framework contains the following modules: a 3D kidney and tumor segmentation model constructed by 3D-UNet, a multi-level feature extractor based on the region of interest, and a partial or radical nephrectomy prediction classifier by XGBoost. The fivefold cross-validation strategy was used to get a robust model. A quantitative model interpretation method called the Shapley Additive Explanations was conducted to explore the contribution of each feature., Results: In the prediction of partial versus radical nephrectomy, the combination of multi-level features achieved better performance than any single-level feature. For the internal validation, the AUROC was 0.93 ± 0.1, 0.94 ± 0.1, 0.93 ± 0.1, 0.93 ± 0.1, and 0.93 ± 0.1, respectively, as determined by the fivefold cross-validation. The AUROC from the optimal model was 0.82 ± 0.1 in the external testing set. The tumor shape Maximum 3D Diameter plays the most vital role in the model decision., Conclusions: The automated surgical decision framework for partial or radical nephrectomy based on 3D-CT multi-level anatomical features exhibits robust performance in renal cell carcinoma. The framework points the way towards guiding surgery through medical images and machine learning., Clinical Relevance Statement: We proposed an automated analytic framework that can assist surgeons in partial or radical nephrectomy decision-making. The framework points the way towards guiding surgery through medical images and machine learning., Key Points: • The 3D-CT multi-level anatomical features provide a more accurate prediction of surgical decision-making for partial or radical nephrectomy in renal cell carcinoma. • The data from multicenter study and a strict fivefold cross-validation strategy, both internal validation set and external testing set, can be easily transferred to different tasks of new datasets. • The quantitative decomposition of the prediction model was conducted to explore the contribution of each extracted feature., (© 2023. The Author(s).)

The non-Hermitian skin effect is a distinctive phenomenon in non-Hermitian systems, which manifests as the anomalous localization of bulk states at the boundary. To understand the physical origin of the non-Hermitian skin effect, a bulk band characterization based on the dynamical degeneracy on an equal frequency contour is proposed, which reflects the strong anisotropy of the spectral function. In this paper, we report the experimental observation of a newly-discovered geometry-dependent non-Hermitian skin effect and dynamical degeneracy splitting in a two-dimensional acoustic crystal and reveal their remarkable correspondence by performing single-frequency excitation measurements. Our work not only provides a controllable experimental platform for studying the non-Hermitian physics, but also confirms the unique correspondence between the non-Hermitian skin effect and the dynamical degeneracy splitting, paving a new way to characterize the non-Hermitian skin effect., Competing Interests: Conflict of interest The authors declare that they have no conflict of interest., (Copyright © 2023 Science China Press. Published by Elsevier B.V. All rights reserved.)

Crop fungal diseases pose a serious threat to global crop production and quality. Developing new and efficient fungicides is an important measure to control crop diseases. Phenylthiazole was found to be an excellent antifungal skeleton based on our previous study on the structural optimization and biological activity of the natural product thiasporine A. To find new fungicides, 45 phenylthiazole derivatives containing an acylhydrazone moiety were designed and synthesized by the principle of active substructure splicing. Forty-two of the forty-five compounds are novel, except for compounds E1 , E14 , and E33 . Their structures were structurally characterized by 1 H NMR, 13 C NMR, and HRMS. The antifungal activities of the target compounds against Magnaporthe oryzae Colletotrichum camelliaet , Bipolaris maydis , and Sclerotinia sclerotiorum were evaluated at 25 μg/mL. The bioassay results revealed that most of these compounds exhibited excellent antifungal activities against M. oryzae and C. camelliaet at 25 μg/mL. In particular, compounds E4 , E10 , E14 , E17 , E23 , E26 , and E27 showed the inhibition rate of more than 80% against M. oryzae , with EC 50 values of 1.66, 2.01, 2.26, 1.45, 1.50, 1.29, and 2.65 μg/mL, respectively, which were superior to that of the commercial fungicides Isoprothiolane (EC 50 = 3.22 μg/mL) and Phenazine-1-carboxylic acid (EC 50 = 27.87 μg/mL). The preliminary structure-activity relationship (SAR) results suggested that introducing methyl, halogen, or methoxy at the ortho-position of R 1 and the para-position of R 2 can endow the final structure with excellent antifungal activity against M. oryzae . The current results provide useful data for developing phenylthiazole derivatives as new fungicides for controlling rice blast caused by M. oryzae .

Background: Placenta accreta spectrum (PAS) is a significant contributor to maternal morbidity and mortality. Our objective was to develop a quantitative analysis framework utilizing magnetic resonance imaging (MRI)-anatomical-clinical features to predict 3 clinically significant parameters in patients with PAS: placenta subtype (invasive vs . non-invasive placenta), intraoperative bleeding (≥1,500 vs . <1,500 mL), and hysterectomy risk (hysterectomy vs . non-hysterectomy)., Methods: A total of 125 pregnant women with PAS from 2 medical centers were enrolled into an internal training set and an external testing set. Some 21 MRI-anatomical-clinical features were integrated as input into the framework. The proposed quantitative analytic framework contains mainly 3 classifiers built by extreme gradient boosting (XGBoost) and their testing in external datasets. We also further compared the accuracy of placenta subtype prediction between the proposed model and 4 radiologists. A quantitative model interpretation method called SHapley Additive exPlanations (SHAP) was conducted to explore the contribution of each feature., Results: The placenta subtype (invasive vs . non-invasive), intraoperative bleeding (≥1,500 vs . <1,500 mL), and hysterectomy risk (hysterectomy vs . non-hysterectomy) demonstrated impressive area under the receiver operating characteristic curve (AUROC) values of 0.93, 0.88, and 0.90, respectively, in the internal validation set. Even in the external testing set, these metrics maintained their strength, achieving AUROC values of 0.91, 0.82, and 0.82, respectively. Comparing our proposed framework to the 4 radiologists, our model exhibited superior accuracy, specificity, and sensitivity in predicting placental subtypes within the external testing cohort. The features associated with intraplacental dark T2 bands played a crucial role in the decision-making process of all 3 prediction models., Conclusions: The quantitative analysis framework can provide a robust method for classification of placenta subtype (invasive vs . non-invasive placenta), intraoperative bleeding (≥1,500 vs . <1,500 mL), and hysterectomy risk (hysterectomy vs . non-hysterectomy) based on MRI-anatomical-clinical features in PAS., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-23-142/coif). The authors have no conflicts of interest to declare., (2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

Background: Plant pathogenic fungal infections have become a severe threat to the yield and quality of agricultural products, and new green antifungal agents with high efficiency and low toxicity are needed. In this study, a series of thiasporine A derivatives containing phenylthiazole-1,3,4-oxadiazole thione (ketone) structures were designed and synthesized, and their antifungal activities against six invasive and highly destructive phytopathogenic fungi were evaluated., Results: The results found that all compounds showed moderate to potent antifungal activity against six phytopathogenic fungi, and most of the E series compounds showed remarkable antifungal activity against Sclerotinia sclerotiorum and Colletotrichum camelliaet. In particular, compounds E1-E5, E7, E8, E13, E14, E17, and E22 showed more significant antifungal activity against S. sclerotiorum, with half-maximal effective concentration (EC 50 ) values of 0.22, 0.48, 0.56, 0.65, 0.51, 0.39, 0.60, 0.56, 0.60, 0.63, and 0.45 μg mL -1 , respectively, which were superior to that of carbendazim (0.70 μg mL -1 ). Further activity studies showed that compound E1 possessed superior curative activities against S. sclerotiorum in vivo and better inhibitory effects on sclerotia germination and the formation of S. sclerotiorum compared with those of carbendazim., Conclusions: This study indicates that these thiasporine A derivatives containing phenylthiazole-1,3,4-oxadiazole thione structures might be used as antifungal agents against S. sclerotiorum. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

High level resistance for a variety of insecticides has emerged in Bemisia tabaci, a globally notorious insect. Neonicotinoid insecticides have been applied widely to control B. tabaci. Whether a differentially expressed gene CYP6DB3 discovered from transcriptome data of B. tabaci is involved in the resistance to neonicotinoid insecticides remains unclear. In the study, CYP6DB3 expression was significantly up-regulated in both thiamethoxam- and imidacloprid-resistant strains relative to the susceptive strains. We also found that CYP6DB3 expression was up-regulated after B. tabaci adults were exposed to thiamethoxam and imidacloprid. Moreover, knocking down CYP6DB3 expression via feeding corresponding dsRNA significantly reduced CYP6DB3 mRNA levels by 34.1%. Silencing CYP6DB3 expression increased the sensitivity of B. tabaci Q adults against both thiamethoxam and imidacloprid. Overexpression of CYP6DB3 gene reduced the toxicity of imidacloprid and thiamethoxam to transgenic D. melanogaster. In addition, metabolic studies showed that CYP6DB3 can metabolize 24.41% imidacloprid in vitro. Collectively, these results strongly support that CYP6DB3 plays an important role in the resistance of B. tabaci Q to imidacloprid and thiamethoxam. This work will facilitate a deeper insight into the part of cytochrome P450s in the evolution of insecticide resistance and provide a theoretical basis for the development of new integrated pest resistance management., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Rice sheath blight caused by Rhizoctonia solani Kühn is a major fungal disease that plagues commercially grown rice. Occurring mainly in leaf sheaths and leaves, the disease leads to great losses in food production. β-amino-butyric acid (BABA) has been demonstrated to activate an induced resistance response and is a potent inducer of broad-spectrum disease resistance in different plant species. In this study, β-amino-butyric acid conjugate of phenazine-1-carboxylic acid (PCA) with prominent induced resistance to rice sheath blight was tested. The in vitro fungicidal activity, as well as in vivo efficacy, systemicity, induced resistance and defense enzyme activity of BABA conjugate of PCA against R. solani in rice seedlings was systematically evaluated. The results indicated that in vitro fungicidal activity of PCA-β-aminobutyric acid (4e) against R. solani was lower than that of PCA, but in vivo curative ability of 4e was the highest among all tested compounds. The systemicity tests in rice seedlings revealed that PCA did not possess phloem mobility, while 4e exhibited moderate phloem mobility but much lower thanα-amino-butyric acid conjugate of PCA (4d). In addition, Compound 4e showed the highest induced activity against rice sheath blight. The observed effects of defense enzymes help to explain this high level of induced activity. The current research results indicate that in rice seedlings, BABA conjugate of PCA induce observable resistance to rice sheath blight and exhibit moderate phloem mobility, which could be used as an induced resistance fungicide against rice sheath blight in commercial rice production. The BABA conjugate of PCA might provide a useful example of induced resistance to R. solani., Competing Interests: Declaration of Competing Interest The authors declare they have no conflicts of interest, including specific financial interest and relationships and affiliations relevant to the subject of manuscript. The manuscript has been approved by all authors for publication., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Pressure-stabilized high-entropy sulfide (FeCoNiCuRu)S 2 (HES) is proposed as an anode material for fast and long-term stable lithium/sodium storage performance (over 85% retention after 15 000 cycles @10 A g -1 ). Its superior electrochemical performance is strongly related to the increased electrical conductivity and slow diffusion characteristics of entropy-stabilized HES. The reversible conversion reaction mechanism, investigated by ex-situ XRD, XPS, TEM, and NMR, further confirms the stability of the host matrix of HES after the completion of the whole conversion process. A practical demonstration of assembled lithium/sodium capacitors also confirms the high energy/power density and long-term stability (retention of 92% over 15 000 cycles @5 A g -1 ) of this material. The findings point to a feasible high-pressure route to realize new high-entropy materials for optimized energy storage performance., (© 2023 Wiley-VCH GmbH.)

Amino acid conjugates of pesticides can promote the phloem translocation of parent ingredients, allowing for the reduction of usage, and decreased environmental pollution. Plant transporters play important roles in the uptake and phloem translocation of such amino acid-pesticide conjugates such as L-Val-PCA (L-valine-phenazine-1-carboxylic acid conjugate). However, the effects of an amino acid permease, RcAAP1, on the uptake and phloem mobility of L-Val-PCA are still unclear. Here, the relative expression levels of RcAAP1 were found to be up-regulated 2.7-fold and 2.2-fold by the qRT-PCR after L-Val-PCA treatments of Ricinus cotyledons for 1 h and 3 h, respectively. Subsequently, expression of RcAAP1 in yeast cells increased the L-Val-PCA uptake (0.36 μmol/10 7 cells), which was 2.1-fold higher than the control (0.17 μmol/10 7 cells). Pfam analysis suggested RcAAP1 with its 11 transmembrane domains belongs to the amino acid transporter family. Phylogenetic analysis found RcAAP1 to be strongly similar to AAP3 in nine other species. Subcellular localization showed that fusion RcAAP1-eGFP proteins were observed in the plasma membrane of mesophyll cells and phloem cells. Furthermore, overexpression of RcAAP1 for 72 h significantly increased the phloem mobility of L-Val-PCA in Ricinus seedlings, and phloem sap concentration of the conjugate was 1.8-fold higher than the control. Our study suggested that RcAAP1 as carrier was involved in the uptake and phloem translocation of L-Val-PCA, which could lay foundation for the utilization of amino acids and further development of vectorized agrochemicals., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Xiao, Hu, Hsiang and Li.)

In the search for crop protectants, amino acid ester conjugates have been widely investigated as potential antifungal agents. In this study, a series of rhein-amino acid ester conjugates were designed and synthesized in good yields, and their structures were confirmed by 1 H-NMR, 13 C-NMR and HRMS. The bioassay results revealed that most of the conjugates exhibited potent inhibitory activity against R. solani and S. sclerotiorum . In particular, conjugate 3c had the highest antifungal activity against R. solani with an EC 50 value of 0.125 mM. For S. sclerotiorum , conjugate 3m showed the highest antifungal activity with an EC 50 value of 0.114 mM. Satisfactorily, conjugate 3c exhibited better protective effects than that of the positive control, physcion, against powdery mildew in wheat. This research supports the role of rhein-amino acid ester conjugates as potential antifungal agents for plant fungal diseases.

Chilo suppressalis Walker (Lepidoptera: Crambidae) is a devastating rice crop pest in China. Chemical insecticides have been used to effectively managing C . suppressalis field populations in most of China's agricultural regions. However, due to the intensive and extensive application of these insecticides, C . suppressalis has developed widespread resistance to many active ingredients. Thus, insecticide resistance development is a genuine concern for all crop specialists and growers. In this study, using the topical application method, we assessed the susceptibility of forty-six field populations of C . suppressalis to three insecticides in three Central Chinese provinces from 2010 to 2021. Our findings revealed that field populations of C . suppressalis built moderate to high levels of resistance to triazophos (Resistance Ratio (RR) = 41.9-250.0 folds), low to moderate levels of resistance to chlorpyrifos (RR = 9.5-95.2 folds), with the exception of the Zhijiang population in 2013 and the Xinyang population in 2015 at 4.8 folds and 3.4 folds resistance rates, respectively, despite showing susceptibility, and low and moderate levels of resistance to abamectin (RR = 4.1-53.5 folds). There were significant correlations between the activity of the detoxification enzymes (CarE) and the log LD 50 values of triazophos. These results should help effective insecticide resistance management strategies reduce the risk of rapid build-ups of resistance to insecticides and slow down the process of selection for insecticide resistance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Meng, Huang, Wan, Li, Li and Zhang.)

Aims: Short-wavelength blue light damaged retina by the oxidative stress in the retinal pigment epithelial (RPE) cells. Filtering blue light from screen could reduce blue hazard, whereas it inevitably altered color-gamut coverage and color-deviation level. Although abnormal fundus-vascular density (FVD) sometimes indicated fundus disease, few researchers noticed its responses to the variation of color-gamut coverage and color-deviation level., Methods: In this study, we performed cellular experiments and analyzed the RPE cell viabilities (CVs) in spectrums with different blue (455-475 nm) ratios to describe the corresponding oxidative-stress levels. Further, we investigated the effects of color-gamut and deviation on FVD variations during the screen-watching task using human factor experiments with 30 participants (university students, including 17 males and 13 females, 21 to 30 years old)., Results: RPE CVs were similar in different spectrums, implying that non-oxidative blue filtering hardly contributed to CV improvement. Color-deviation level seems to induce more significant effects on the visual function compared to color-gamut coverage, and MTF and FVD presents similar variation trends during the visual task., Conclusion: Oxidative-free blue filtering contributed little to decrease retinal oxidative stress yet caused color-deviation increase, which caused significant FVD reduction., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2022 Jianqi Cai et al.)

To improve the selectivity of the fenoxaprop herbicide to rice and barnyard grass, a series of fenoxaprop-P-ethyl-amino acid ester conjugates were designed and synthesized, and tested for biological activity as well as their phloem mobility. The bioassay results indicated that the target compounds possessed better activity against barnyard grass (Echinochloa crusgalli) than rape (Brassica campestris L.) at the concentration of 0.5 mmol/L. Compounds 3h and 3i, showed more than 70% control efficiency against barnyard grass, while less than 30% for rape. The compounds showed less impact on rice after spray treatment than in the germination test. Compounds 3i, 3j, and 3k showed excellently herbicidal activities against barnyard grass and low phytotoxicity to rice. Compound 3k showed 6.1% phytotoxicity to rice at a spray concentration of 0.25 mmol/L, better than fenoxaprop-P-ethyl (61.6%) at the same concentration. The selectivity results of the target compounds revealed that most of compounds obviously reduced phytotoxicity to rice while retaining herbicidal activity of barnyard grass. The herbicidal activity of compound 3d compared to FPE was increased by 50%, while its safety on rice was also increased by 50%. The concentration of the compounds in barnyard grass roots was higher than in rice roots, showing greater phloem mobility. In particular, the concentration of compound 3d on barnyard grass exhibited 142.72 mg/kg which was 3 times as much as Fenoxaprop, while its concentration on rice exhibited 3.65 mg/kg, the results revealed that the difference of phloem mobility might be the important reason for causing the selectivity., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Plant plasma membrane transporters play essential roles during the translocation of vectorized agrochemicals. Therefore, transporters associated with phloem loading of vectorized agrochemicals have drawn increasing attention. As a model system, castor bean (Ricinus communis L.) has been widely used to detect the phloem mobility of agrochemicals. However, there is still a lack of an efficient protocol for the Ricinus seedling model system that can be directly used to investigate the recognition and phloem loading functions of plasmalemma transporters toward vectorized agrochemicals., Results: Here, using vacuum infiltration strategy, we overexpressed the coding gene for enhanced green fluorescent protein (eGFP) in R. communis seedlings by Agrobacterium tumefaciens-mediated transformation system. Strong fluorescence signals were observed in leaves, demonstrating that exogenous genes can be successfully overexpressed in seedlings. Subsequently, gene expression time and vacuum infiltration parameters were optimized. Observation of fluorescence and qRT-PCR analysis showed that eGFP strength and expression level reached a peak at 72 h after overexpression in seedlings. Parameter optimization showed Agrobacterium concentration at OD 600  = 1.2, and infiltration for 20 min (0.09 MPa), return to atmospheric pressure, and then infiltration for another 20 min, were the suitable transformation conditions. To test the application of vacuum agroinfiltration in directly examining the loading functions of plasma membrane transporters to vectorized agrochemicals in seedlings, two LHT (lysine/histidine transporter) genes, RcLHT1 and RcLHT7, were overexpressed. Subcellular localization showed the strong fluorescent signals of the fusion proteins RcLHT1-eGFP and RcLHT7-eGFP were observed on the cell membrane of mesophyll cells, and their relative expression levels determined by qRT-PCR were up-regulated 47- and 52-fold, respectively. Furthermore, the concentrations of L-Val-PCA (L-valine-phenazine-1-carboxylic acid conjugate) in phloem sap collected from seedling sieve tubes were significantly increased 1.9- and 2.3-fold after overexpression of RcLHT1 and RcLHT7, respectively, implying their roles in recognition and phloem loading of L-Val-PCA., Conclusions: We successfully constructed a transient expression system in Ricinus seedlings and laid the foundation for researchers to directly investigate the loading functions of plasma membrane transporters to vectorized agrochemicals in the Ricinus system., (© 2022. The Author(s).)

Phenazine-1-carboxylic acid (PCA) is a natural product that has been proven effective against a number of soil-borne fungal phytopathogens and registered for biofungicide against rice sheath blight in China. In order to improve the phloem mobility of phenazine-1-carboxylic acid (PCA), four PCA derivatives were designed and synthesized by conjugating PCA with l-alanine methyl ester, d-alanine methyl ester, l-alanine and d-alanine respectively. In vitro and planta bioassays results showed that conjugates L-PAM and D-PAM exhibited higher fungicidal activities against Rhizoctonia solani Kuhn than PCA while L-PA and D-PA were less active than PCA. The concentration of conjugates in Ricinus communis phloem sap was determined by HPLC. The results showed that only L-PA exhibited phloem mobility among these conjugates, and its concentration in Ricinus communis phloem sap increased with the increase of time (the maximum concentration was 12.69μM within 5h). However, the results of pot experiments showed that L-PA and other conjugates didn't exhibited the inhibition for the growth of Rhizoctonia solani Kuhn in the lower leaves after treatment in the upper leaves of rice seedlings. This may be due to the poor plant absorbility for them or their too little amount of accumulation in the lower leaves., (Copyright © 2017 Elsevier Inc. All rights reserved.)