In Vivo and In Vitro Interactions between Exopolysaccharides from Bacillus thuringensis HD270 and Vip3Aa11 Protein.

Bacillus thuringiensis (Bt) secretes the nutritional insecticidal protein Vip3Aa11, which exhibits high toxicity against the fall armyworm (Spodoptera frugiperda). The Bt HD270 extracellular polysaccharide (EPS) enhances the toxicity of Vip3Aa11 protoxin against S. frugiperda by enhancing the attachment of brush border membrane vesicles (BBMVs). However, how EPS-HD270 interacts with Vip3Aa11 protoxin in vivo and the effect of EPS-HD270 on the toxicity of activated Vip3Aa11 toxin are not yet clear. Our results indicated that there is an interaction between mannose, a monosaccharide that composes EPS-HD270, and Vip3Aa11 protoxin, with a dissociation constant of Kd = 16.75 ± 0.95 mmol/L. When EPS-HD270 and Vip3Aa11 protoxin were simultaneously fed to third-instar larvae, laser confocal microscopy observations revealed the co-localization of the two compounds near the midgut wall, which aggravated the damage to BBMVs. EPS-HD270 did not have a synergistic insecticidal effect on the activated Vip3Aa11 protein against S. frugiperda. The activated Vip3Aa11 toxin demonstrated a significantly reduced binding capacity (548.73 ± 82.87 nmol/L) towards EPS-HD270 in comparison to the protoxin (34.96 ± 9.00 nmol/L). Furthermore, this activation diminished the affinity of EPS-HD270 for BBMVs. This study provides important evidence for further elucidating the synergistic insecticidal mechanism between extracellular polysaccharides and Vip3Aa11 protein both in vivo and in vitro.

The 'Candidatus Phytoplasma ziziphi' effectors SJP1/2 negatively control leaf size by stabilizing the transcription factor ZjTCP2 in jujube.

Phytoplasmas manipulate host plant development to benefit insect vector colonization and their own invasion. However, the virulence factors and mechanisms underlying small-leaf formation caused by jujube witches' broom (JWB) phytoplasmas remain largely unknown. Here, effectors SJP1 and SJP2 from JWB phytoplasmas were identified to induce small-leaf formation in jujube (Ziziphus jujuba). In vivo interaction and expression assays showed that SJP1 and SJP2 interacted with and stabilized the transcription factor ZjTCP2. Overexpression of SJP1 and SJP2 in jujube induced ZjTCP2 accumulation. In addition, the abundance of miRNA319f_1 was significantly reduced in leaves of SJP1 and SJP2 transgenic jujube plants and showed the opposite pattern to the expression of its target, ZjTCP2, which was consistent with the pattern in diseased leaves. Overexpression of ZjTCP2 in Arabidopsis promoted ectopic leaves arising from the adaxial side of cotyledons and reduced leaf size. Constitutive expression of the miRNA319f_1 precursor in the 35S::ZjTCP2 background reduced the abundance of ZjTCP2 mRNA and reversed the cotyledon and leaf defects in Arabidopsis. Therefore, these observations suggest that effectors SJP1 and SJP2 induced small-leaf formation, at least partly, by interacting with and activating ZjTCP2 expression both at the transcriptional and the protein level, providing new insights into small-leaf formation caused by phytoplasmas in woody plants.

Biochemical and Transcriptome Analyses Reveal a Stronger Capacity for Photosynthate Accumulation in Low-Tillering Rice Varieties.

Moderate control of rice tillering and the development of rice varieties with large panicles are important topics for future high-yield rice breeding. Herein, we found that low-tillering rice varieties stopped tillering earlier and had a larger leaf area of the sixth leaf. Notably, at 28 days after sowing, the rice seedlings of the low-tillering group had an average single-culm above-ground biomass of 0.84 g, significantly higher than that of the multi-tillering group by 56.26%, and their NSC (non-structural carbohydrate) and starch contents in sheaths were increased by 43.34% and 97.75%, respectively. These results indicated that the low-tillering group of rice varieties had a stronger ability to store photosynthetic products in the form of starch in their sheaths, which was thus more beneficial for their large panicle development. The results of carbon and nitrogen metabolism analyses showed that the low-tillering group had a relatively strong carbon metabolism activity, which was more favorable for the accumulation of photosynthesis products and the following development of large panicles, while the multi-tillering group showed relatively strong nitrogen metabolism activity, which was more beneficial for the development and formation of new organs, such as tillers. Accordingly, in the low-tillering rice varieties, the up-regulated genes were enriched in the pathways mainly related to the synthesis of carbohydrates, while the down-regulated genes were mainly enriched in the nitrogen metabolism pathways. This study provides new insights into the mechanism of rice tillering regulation and promotes the development of new varieties with ideal plant types.

Inositolphosphorylceramide synthases, OsIPCSs, regulate plant height in rice.

Inositolphosphorylceramide synthase (IPCS) catalyses ceramides and phosphatidylinositol (PI) into inositolphosphorylceramide (IPC), which is involved in the regulation of plant growth and development. A total of three OsIPCS family genes have been identified in rice. However, most of their functions remain unknown. Here, the functions of OsIPCSs were analyzed by CRISPR/Cas9 technology, lipidomics analysis, and transcriptomics analysis. Single-gene mutation of OsIPCSs resulted in dwarf phenotype. Among them, the phenotype of osipcs3 mutant was more severe. Multi-gene mutation of OsIPCS genes led to more severe phenotypes, indicating the additive effects of OsIPCSs. We further determined that a significant decrease in epidermal cell elongation of internode in the mutants. There was a significant decrease in the content of IPC detected in the osipcs2/3 and osipcs1/2/3 mutants. The contents of glycosyl inositol phosphoryl ceramide (GIPC) were also decreased by 20% and 10% in osipcs2/3 and osipcs1/2/3, respectively. The results of RNA-seq showed that numerous DEGs found to be associated with cellular component organization, anatomical structure morphogenesis, and cell growth in the osipcs2, osipcs2/3, and osipcs1/2/3. Taken together, OsIPCSs may be involved in the regulation of plant height through affecting cell growth and sphingolipid metabolism in rice.

Carotenoid components and their biosynthesis in a bud mutant of Shiranui mandarin (Citrus reticulata Blanco) with citrine flavedo.

Carotenoids are secondary metabolite responsible for colored pigments in plants and microbes (Li et al., 2022). They are a class of C40 tetraterpenoids consisting of eight isoprenoid units, and can be classified into carotenes and xanthophylls on the basis of their functional groups (Saini et al., 2015). Carotenes can be linear (phytoene, phytofluene, and ζ|-carotene) or branched (ß|-carotene and α|-carotene). Xanthophylls comprise ß,ß|-xanthophylls (ß|-cryptoxanthin, zeaxanthin, violaxanthins, and neoxanthin) and ß,ε|-xanthophylls (α-cryptoxanthin, α-carotene, and lutein). Citrus fruits are complex sources of carotenoids, which are the principal pigments responsible for the typical orange color of most types (Chen, 2020). The difference in total carotenoid content and the diversity of carotenoid isomer proportion also accounts for other colors of citrus fruits, such as yellow, red, and pink (Chen, 2020).

ipa1 improves rice drought tolerance at seedling stage mainly through activating abscisic acid pathway.

KEY MESSAGE: ipa1 enhances rice drought tolerance mainly through activating the ABA pathway. It endows rice seedlings with a more developed root system, smaller leaf stomata aperture, and enhanced carbon metabolism. Drought is a major abiotic stress to crop production. IPA1 (IDEAL PLANT ARCHITECTURE 1)/OsSPL14 encodes a transcription factor and has been reported to function in both rice ideal plant architecture and biotic resistance. Here, with a pair of IPA1 and ipa1-NILs (Near Iso-genic Lines), we found that ipa1 could significantly improve rice drought tolerance at seedling stage. The ipa1 plants had a better-developed root system and smaller leaf stomatal aperture. Analysis of carbon-nitrogen metabolism-associated enzyme activity, gene expression, and metabolic profile indicated that ipa1 could tip the carbon-nitrogen metabolism balance towards an increased carbon metabolism pattern. In both the control and PEG-treated conditions, ABA content in the ipa1 seedlings was significantly higher than that in the IPA1 seedlings. Expression of the ABA biosynthesis genes was detected to be up-regulated, whereas the expression of ABA catabolism genes was down-regulated in the ipa1 seedlings. In addition, based on yeast one-hybrid assay and dual-luciferase assay, IPA1 was found to directly activate the promoter activity of OsHOX12, a transcription factor promoting ABA biosynthesis, and OsNAC52, a positive regulator of the ABA pathway. The expression of OsHOX12 and OsNAC52 was significantly up-regulated in the ipa1 plants. Combined with the previous studies, our results suggested that ipa1 could improve rice seedling drought tolerance mainly through activating the ABA pathway and that regulation of the ipa1-mediated ABA pathway will be an important strategy for improving drought resistance of rice.

Genome-Wide Comprehensive Analysis of the Nitrogen Metabolism Toolbox Reveals Its Evolution and Abiotic Stress Responsiveness in Rice (Oryza sativa L.).

Nitrogen metabolism (NM) plays an essential role in response to abiotic stresses for plants. Enzyme activities have been extensively studied for nitrogen metabolism-associated pathways, but the knowledge of nitrogen metabolism-associated genes involved in stress response is still limited, especially for rice. In this study, we performed the genome-wide characterization of the genes putatively involved in nitrogen metabolism. A total of 1110 potential genes were obtained to be involved in nitrogen metabolism from eight species (Arabidopsis thaliana (L.) Heynh., Glycine max (L.) Merr., Brassica napus L., Triticum aestivum L., Sorghum bicolor L., Zea mays L., Oryza sativa L. and Amborella trichopoda Baill.), especially 104 genes in rice. The comparative phylogenetic analysis of the superfamily revealed the complicated divergence of different NM genes. The expression analysis among different tissues in rice indicates the NM genes showed diverse functions in the pathway of nitrogen absorption and assimilation. Distinct expression patterns of NM genes were observed in rice under drought stress, heat stress, and salt stress, indicating that the NM genes play a curial role in response to abiotic stress. Most NM genes showed a down-regulated pattern under heat stress, while complicated expression patterns were observed for different genes under salt stress and drought stress. The function of four representative NM genes (OsGS2, OsGLU, OsGDH2, and OsAMT1;1) was further validated by using qRT-PCR analysis to confirm their responses to these abiotic stresses. Based on the predicted transcription factor binding sites (TFBSs), we built a co-expression regulatory network containing transcription factors (TFs) and NM genes, of which the constructed ERF and Dof genes may act as the core genes to respond to abiotic stresses. This study provides novel sights to the interaction between nitrogen metabolism and the response to abiotic stresses.

Identification, expression and miRNA targeting of auxin response factor genes related to phyllody in the witches' broom disease of jujube.

Jujube witches' broom (JWB) disease, associated with the presence of phytoplasmas, induces huge crop losses in the woody perennial fruit tree Ziziphus jujuba. An imbalance in the phytohormone auxin is thought to be a key factor in the development of the witches' broom symptoms, and in the alteration of floral development into leafy structures, termed phyllody. The Auxin Response Factor (ARF) gene family controls auxin-responsive gene expression during plant growth and development. However, it remains unknown if the ARF genes are involved in the formation of leaf-like flowers. In the present study, sixteen jujube ARF genes were identified bioinformatically and annotated based on the Z. jujuba cv. Dongzao genome. The ZjARFs were homologous to 12 out of the 23 Arabidopsis ARFs and were distributed in 8 jujube chromosomes and 3 unmapped scaffolds. Phylogenetic analysis grouped the ZjARFs into three classes. Spatio-temporal expression analysis revealed that the ZjARF genes were differentially expressed among different tissues during normal development. The expression of seven ZjARF genes was significantly decreased from flower buds to flowering. JWB-infected jujube plants developed the typical phyllody symptoms and showed lower auxin accumulation during floral development. ZjARF1, ZjARF2, ZjARF3, ZjARF4 and ZjARF8 resulted differentially regulated after phytoplasma infection. ZjARF4 was down-regulated before and during floral development in phytoplasma-infected plants, but it was significantly up-regulated before flowering and down-regulated during flowering in the healthy plants. Target site analysis showed that miRNA167, miRNA529 and miRNA2950 could directly target ZjARF4. Together, the data showed that the auxin-controlled ARF4 gene is likely involved in the disruption of floral development in phytoplasma-infected jujube plants.

Synthesis, G-Quadruplex DNA binding and cytotoxic properties of naphthalimide substituted styryl dyes.

G-Quadruplex DNAs, formed by G-rich DNA sequences in human genes, are promising targets for design of cancer drugs. In this study, two naphthalimide substituted styryl dyes with different sizes of aromatic groups were synthesized. The spectral analysis showed that the dye X-2 with a large aromatic group formed aggregates in buffer solution displaying very weak fluorescence intensity, and disaggregated in the presence of G-Quadruplex DNAs with large intensity enhancements (up to ~1800 fold). Moreover, X-2 displayed good selectivity to G-Quadruplex DNAs. In contrast, dye X-3 with the smaller aromatic group had much lower fluorescence enhancements and poor selectivity to G-Quadruplex DNAs, suggesting that the suitably sized aromatic ring was essential for the interaction with G-Quadruplex. Further binding studies suggested that X-2 mainly bound on G-quartet surface through end-stacking mode. Cytotoxicity assay showed that both of the two dyes showed good anti-proliferative activities against the cancer cell lines and less cytotoxicity in non-malignant cell lines, which were better than a standard drug 5-fluorouracil. In addition, living cell imaging was also studied and demonstrated the potential applications of the new dye X-2 in bioassays and cell imaging.

Swelling suppression of black cotton soil by means of liquid immersion and surface modification.

Although the surface organic modification of smectite has been investigated widely, the swelling behavior of clays has been scarcely studied with consideration of civil engineering applications. In this work a facile strategy of liquid-immersion (dilute H2SO4 aqeuous solution) was proposed, and the 3-aminopropyltrimethoxysilane (APS) was utilized as surface modifier to suppress expansibility of black cotton soil (BCS) which is a type of highly swelling soils in tropical areas. Factors such as the incorporation dosage of APS, surface characters of soil treated by solution of H2SO4 or Na2CO3, and reaction temperatures/time were investigated to get lower swelling ratios. The treatment of BCS by H2SO4 was found more effective in immobilizing APS molecules, and hydronium ions were suppressed after the APS modification. The free swelling index (FSI) of BCS was decreased from 120% to 15% after treatment with H2SO4 and appropriate amount of APS modification. The reaction can be completed within several hours at the room temperature to ~80 °C. The soil samples were characterized by different means including the X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscope, thermogravimetric analysis and Zeta potential measurements. The APS molecules were found to react with -OH groups of the clay, and the hydrophobic groups provide surface hydrophobicity, which prevents hydration of cations within clay minerals. The APS was indicated to re-constructed lamellar structures of smectites after H2SO4 treatment, which suppressed the intra-crystalline and the subsequent osmotic swelling. This research highlights the liquid immersion and surface modification is applicable in diminishing swelling ratios of highly expansive black cotton soil.

Chemoradiotherapy with Concurrent Regional Arterial Chemotherapy for Locally Bulky Unresectable Rectal Cancer: A Case Series.

INTRODUCTION: We evaluated the feasibility and efficacy of chemoradiotherapy with concurrent regional arterial chemotherapy (CRT/RAC) for locally bulky unresectable rectal cancer (LBURC). CASE PRESENTATION: We retrospectively reviewed 9 patients with LBURC who received CRT/RAC between January 2012 and December 2018. The regimen consisted of chemoradiotherapy and 3 cycles of regional arterial chemotherapy. Surgery was performed 6 weeks after completion of radiotherapy. The median longest tumor diameter was 10 cm (range 8.2-13.6). Grade 3 toxicity and postoperative complications occurred in 3 and 4 patients, respectively. All patients showed partial response according to the Response Evaluation Criteria in Solid Tumors (RECIST). One patient refused the operation after completion of the scheduled regimen but then had a bowel obstruction and had to undergo urgent surgery. Of the 8 patients who underwent scheduled surgery, all had R0 resection without multivisceral resection; 3 achieved pathological complete response and 5 exhibited good tumor regression. The median follow-up period was 35 months (range 9-63). Recurrences occurred in 3 of 9 patients (pelvic relapses in 2 and lung in 1). CONCLUSION: CRT/RAC appeared to be beneficial to LBURC, as it achieves remarkable rates of R0 resection, good tumor regression, and pathologic complete response. These preliminary results have to be confirmed in larger cohorts of patients.

[Simultaneous determination of four anthraquinones in rat plasma by HPLC-FLD method and its pharmacokinetic study].

This paper aims to develop a method for the determination of aloe-emodin, rhein, chrysophanol and physcion and study the pharmacokinetic properties of four anthraquinones in rat plasma after oral administration of gardenia and rhubarb decoction. The plasma concentrations at different time points of four anthraquinones were determined by HPLC-FLD method. Plasma samples were extracted with liquid-liquid extraction procedure. Plasma samples were separated on a C18 column (4.6 mm x 150 mm, 5 µm), using 0.2% acetic acid and methanol as mobile phase at a flow rate of 1.0 mL min(-1) with gradient elution. The excitation and emission wavelengths were set at 430, 525 nm, respectively. DAS 2.0 software was applied to calculate the pharmacokinetic parameters. The results showed four anthraquinones can be absorbed. The main parameters of aloe-emodin, rhein, chrysophanol and physcion were as follows: C(max) for aloe-emodin was (0.085 ± 0.058), (3.772 ± 1.152), (0.464 ± 0.267), (0.028 ± 0.008) mg x L(-1) respectively; t(max) for rhein was (1.042 ± 0.510), (0.805 ± 0.307), (1.167 ± 0.283), (0.616 ± 0.162) h respectively; t½ for chrysophanol was (3.557 ± 1.250), (6.879 ± 1.126), (5.196 ± 2.032), (4.337 ± 1.816) h; AUC(0-t) for physcion was (0.504 ± 0.130), (9.558 ± 1.106), (2.545 ± 1.554), (0.052 ± 0.018) mg x h x L(-1). This paper developed a selective, accurate and sensitive HPLC-FLD method for the simultaneous determination of four anthraquiones in rat plasma.

[Clinical study of lymph node metastatic pattern of thoracic esophageal squamous carcinoma].

OBJECTIVE: To analyze the patterns of lymph node metastases of thoracic esophageal carcinoma and define the adequate range of lymph node dissection. METHODS: The clinical data of 217 patients with esophageal carcinoma undergoing radical surgical resection of the lymph nodes in three regions were retrospectively analyzed. RESULTS: Lymph node metastases were found in 136 of the 217 patients (62.6%) and skip metastases of the lymph nodes in 12 patients (5.5%). In 3 989 lymph nodes desected, metastases were identified in 454 lymph nodes (11.38%). The rates of lymph node metastasis were 31.7%, 21.2% and 12.1% in the neck, thoracic mediastinum and abdominal cavity, respectively, in upper thoracic esophageal carcinoma, 21.9%, 30.5% and 15.6% in middle thoracic carcinoma, and 9.75%, 12.7% and 34.5% in lower thoracic carcinoma. The degree of tumor differentiation, depth of tumor invasion and lymphatic vessel invasion were factors influencing lymph node metastases (P<0.05). CONCLUSION: Because of the upward, downward and skip metastasis of esophageal carcinoma cells to the lymph nodes, the operable patients with thoracic esophagus carcinoma should receive radical desection of the lymph nodes in the 3 regions to promote the patients' survival.

[Analysis of lymph node metastases of 217 cases of thoracic esophageal carcinoma and its impact on prognosis].

BACKGROUND & OBJECTIVE: At present, the range of lymph node dissection in treatment of thoracic esophageal cancer is still controversial. This study was designed to explore the status of lymph node metastases of thoracic esophageal carcinoma and its influence on the prognosis and to seek reasonable dissecting range of lymph nodes. METHODS: A retrospective study was performed on the clinical data of 217 patients who had underwent radical operation through three-field lymphadenectomy. Nine distinguishing clinicopathological factors possibly influencing survival rate were chosen. A multivariate analysis of these factors was performed by the computerized Cox proportional hazards model. RESULTS: The 1-, 3-, and 5-year survival rates of all patients were 82.6%, 59.8%, and 48.8%, respectively. The lymph node metastasis rate was 62.6% and the leaping metastasis rate of lymph nodes was 5.5%. In 3989 lymph nodes dissected, metastases were detected in 454 (11.38%). The lymph node metastasis rates present in neck, thoracic mediastinum, and abdominal cavity were 31.7%, 21.2%, and 12.1% in upper-thoracic esophageal carcinoma, 21.9%, 30.5%, and 15.6% in middle-thoracic carcinoma, 9.75%, 12.7%, and 34.5% in lower-thoracic carcinoma, respectively. Degree of tumor differentiation, depth of tumor invasion, and lymphatic vessels invasion were the factors influencing lymph nodes metastases, but the length of tumor was not. According to multivariate analysis, depth of tumor invasion, tumor differentiation, the number of lymph nodes metastatic field, and tumor location were of prognostic significance. With the increasing of the number of lymph nodes metastatic field, the survival rate of the patients dropped gradually(P = 0.0284). CONCLUSION: Lymph node metastasis especially the number of lymph node metastatic field is one of key factors affecting the prognosis of patients. Because of the upward, downward, and leaping spreading of esophageal carcinoma cells to the lymph nodes, the patients with thoracic esophageal carcinoma should be given radical operation through three-field lymphadenectomy to promote the 5-years survival rate.

[A prospective study of combined chemoradiotherapy followed by surgery in the treatment of esophageal carcinoma].

OBJECTIVE: To evaluate the effect of combined chemoradiotherapy followed by surgery for patients with esophageal carcinoma. METHODS: Ninety-seven patients with stage II or III esophageal carcinoma without contraindication against operation and chemoradiotherapy, were randomly divided into two groups: combined group (Group A) 48 and control group (Group B) 49. Patients in group A were given neoadjuvant treatment consisted of chemotherapy with 5-fluorouracil and cisplatin for 2 cycles and radiotherapy of DT36 Gy/12 f/17 d. Three weeks later, operation was performed. Patients in group B were given operation alone. Survival rate was calculated with Kaplan-Meier method. Chi and Log-rank test was used to assess the difference between the two groups. RESULTS: The radical resectability of group A and group B were 85.4% and 65.3% (P = 0.018 1). The lymph node metastasis rate of the two groups were 21.7% and 45.7% (P = 0.019 4). The T stage of group A was significantly lowered (P = 0.003 6). The local and regional recurrence rate of two groups were 34.8% and 58.7% (P = 0.023 6), while there was no significant difference in operative complications between the two groups. Significant improvement in the long-term survival rate was observed in group A, especially in patients who achieved partial and complete response with high 5-year survival rate of 56.5%. CONCLUSION: Preoperative neoadjuvant chemoradiotherapy is able to reduce the tumor and tumor stage, lower the lymph node metastasis rate and local or regional recurrence rate, also it can improve radical resectability and long-term survival without increasing the operative complications.