氘标记稻瘟酯的合成及其杀菌活性

氘标记农药作为探针或者内标在农药代谢、毒理研究或者农药残留分析中发挥着重要作用。由于动力学同位素效应,C-D键比C-H键更为稳定,因此氘标记农药可能具有更长的半衰期,以及对非靶标生物更小的毒性。稻瘟酯是一种对水稻恶苗病和稻瘟病有良好防治效果的农用杀菌剂。本项研究利用单电子转移还原氘化反应和氘标记中间体,成功合成了4个不同位点被选择性氘代的稻瘟酯,其中3个化合物未见文献报道,并对其进行了杀菌活性测试。离体杀菌活性测试结果显示,上述4种氘代稻瘟酯对水稻稻瘟病菌和水稻恶苗病菌均具有良好的生物活性,与未被标记的稻瘟酯无显著差异。氘标记稻瘟酯未来可作为代谢、毒理研究的探针及农药残留分析中的内标。     

天维菌素酰化衍生物的合成及杀虫杀螨活性

以天维菌素B、天维菌素B单糖苷和天维菌素B苷元为原料,经选择性C-5羟基保护,在C-13、C-4′和C-4″位引入不同酰基基团,合成了3个系列共23个天维菌素B酰化衍生物,并通过1H NMR、13C NMR和高分辨质谱对所有目标化合物的结构进行了表征。生物活性测定结果表明,所有衍生物对小菜蛾Plutella xylostella、朱砂叶螨Tetranychus cinnabarinus以及松材线虫Bursaphelenchus xylophilus均表现出不同程度的毒杀活性,其中天维菌素B C-4″位衍生物的活性优于C-4′位衍生物及13位衍生物。化合物8e对小菜蛾和松材线虫的毒杀活性最优,LC50值分别为9.2 mg/L和0.42 mg/L,化合物8b对朱砂叶螨的毒性最高,LC50值为0.0019 mg/L,均优于对照药天维菌素B。     

茶足柄瘤蚜茧蜂脂代谢相关的滞育关联基因差异表达分析

本文对茶足柄瘤蚜茧蜂滞育组与正常发育组进行转录组测序,筛选差异表达基因,根据功能注释发现这些滞育关联基因主要与碳水化合物代谢、脂质代谢以及信号转导等途径相关。借助KEGG数据库,共筛选出滞育期间401个与脂代谢相关的差异基因,在滞育期间呈现不同程度的上调表达,涉及了脂肪酸生物合成、甘油脂代谢、类固醇生物合成等代谢途径,除与脂质合成相关的脂肪酸合成酶、超长链脂肪酸延伸酶基因上调表达外,与脂质分解相关的酶,如酯酶同样上调表达,可能与提高茶足柄瘤蚜茧蜂免疫力有关;与激素合成相关基因的上调表达,可能抑制茶足柄瘤蚜茧蜂卵巢发育。     

高效氯氟氰菊酯对东亚小花蝽捕食功能反应的影响

为了研究高效氯氟氰菊酯对东亚小花蝽雌成虫捕食功能反应的影响,比较分析了LC₂₅、LC₅₀、LC₇₅高效氯氟氰菊酯胁迫3日龄东亚小花蝽雌成虫后,对大豆蚜捕食量、寻找效应、猎物密度效应、种内分摊竞争效应和功能反应等的影响。研究表明,对照组与LC₂₅、LC₅₀高效氯氟氰菊酯胁迫的东亚小花蝽成虫受猎物密度效应影响明显,而LC₇₅高效氯氟氰菊酯胁迫的东亚小花蝽成虫受猎物密度效应影响不明显;在药剂浓度为0 mg/L和140 mg/L时,捕食量达到的最大值和最小值分别为12.33和0.83头,寻找效应达到的最大值和最小值分别为0.96和0.10;受不同浓度药剂胁迫的东亚小花蝽成虫对大豆蚜的捕食能力和寻找效应均随着药剂浓度的增加而下降;捕食量随大豆蚜虫口密度增加而增多,种内竞争分摊强度随小花蝽数量增加而增强,平均捕食量降低;在LC₅₀高效氯氟氰菊酯胁迫下,东亚小花蝽成虫捕食作用率方程为E=0.1255P^-0.2956,分摊竞争强度方程为I=0.5401logP^-0.0033。     

玉米粉淀粉含量近红外模型建立与优化

以230份玉米自交系为样本,采用旋光法与一阶导数及去一条直线的光谱预处理法,构建玉米粉样淀粉含量的近红外分析（NIRS）模型。研究标明,该模型可显著提高子粒淀粉含量预测的准确性。该模型的定标标准偏差（RMSEE）、交叉验证标准偏差（RMSECV）、外部验证标准偏差（RMSEP）、定标相关系数（R_cal²）、交叉验证相关系数（R_cv²）、外部验证相关系数（R_cv²）分别为0.609、0.722、0.738、0.909、0.864和0.854。建立的玉米粉样NIRS模型可将预测值与化学值偏差控制在1.7%内,能够准确定量分析玉米子粒淀粉含量,应用于育种材料早期筛选及群体水平粗淀粉分析。     

不同耕作方式对辽西褐土物理性状及玉米根系分布的影响

通过连续3年大田试验,对旋耕、翻耕、深松3种耕作方式下的土壤物理性质、玉米根系分布和产量进行测定。结果表明,与翻耕和旋耕相比,深松显著增加了玉米田土壤耕层厚度和降低了犁底层厚度。在中下层土壤,深松还降低了土壤紧实度和容重,改善了土壤的孔隙状况,有利于玉米根系向下生长,使得中下层土壤的玉米根系不仅更丰富,而且占总根系量的比例也更高,最终提高了玉米产量。本研究表明,深松耕作有利于改善辽西褐土区土壤结构和促进玉米生长。     

金刚砂辅助农杆菌进行玉米基因转化研究

对超声波处理方式进行改进,在超声波处理时,加入金刚砂以辅助EPSPS基因转导到玉米幼胚中。结果表明,800粒处理种子播种出苗93株,玉米苗经大田glyphosate筛选有27株具有抗性,进行PCR电泳检测,显示23株阳性,初步证明EPSPS基因已经转化到玉米植株中,转化率为29%。金刚砂辅助处理玉米基因转化具有可行性,利于生产实际操作。     

基于无人机多光谱遥感的冬小麦冠层叶绿素含量估测研究

为探讨利用无人机多光谱影像监测冬小麦叶绿素含量的可行性,基于北京市大兴区中国水科院试验基地的2019年冬小麦无人机多光谱影像和田间实测冠层叶绿素含量数据,选取16种光谱植被指数,确定对冬小麦冠层叶绿素含量显著相关的植被指数,采用一元二次线性回归和逐步回归分析方法建立各生育时期及全生育期的SPAD值估测模型,通过精度检验确定对冬小麦冠层叶绿素含量监测的最优模型。结果表明,两种分析方法中逐步回归建模效果最佳。拔节期选取4个植被指数(MSR、CARI、NGBDI、TVI)建模效果最好,模型率定的决定系数(r~2)为0.73,模型验证的r~2、相对误差(RE)和均方根误差(RMSE)分别为0.63、2.83%、1.68;抽穗期选取3个植被指数(GNDVI、GOSAVI、CARI)建模效果最好,模型率定的r~2为0.81,模型验证的r~2、RE、RMSE分别为0.63、2.83%、1.68;灌浆期选取2个植被指数(MSR、NGBDI)建模效果最好,模型率定的r~2为0.67,模型验证的r~2、RE、RMSE分别为0.65、2.83%、1.88。因此,无人机多光谱影像结合逐步回归模型可以很好地监测冬小麦SPAD值动态变化。     

ROCK promotes high glucose-induced cardiomyocyte apoptosis by inhi-biting PI3K/Akt signaling pathway

AIMTo investigate whether Rho-associated coiled-coil kinase (ROCK) is involved in high glucose-induced apoptosis of primary cardiomyocytes by regulating PI3K/Akt signaling pathway. METHODSPrimary Wistar rat cardiomyocytes were cultured and identified by α-sarcomeric actin (α-SCA) immunohistochemistry. Cardiomyocytes were treated with 5.5, 33 and 40 mmol/L glucose for 48 h. The cell viability was measured by MTT assay, and the mRNA expression of ROCK1 and ROCK2 in the cardiomyocytes was detected by RT-qPCR. Flow cytometry was used to analyze the apoptosis of the cardiomyocytes. The protein levels of ROCK1, ROCK2, cleaved caspase-3, Bcl-2, PI3K, Akt and p-Akt were determined by Western blot. In order to confirm the regulatory effect of ROCKs on PI3K/Akt signaling pathway, the cells were divided into control group (5.5 mmol/L glucose), high glucose group (33 mmol/L glucose) and high glucose+Y27632 (ROCK inhibitor) group. Western blot was used to detect the protein levels of ROCK1, ROCK2, PI3K, Akt and p-Akt. RESULTSAfter 48 h of high glucose exposure, the values of relative cell viability in 33 and 40 mmol/L glucose groups were (79.71±2.43)% and (68.41±7.49)%, respectively, both of which were significantly decreased compared with normal control group (P<0.05). After 48 h of high glucose exposure, the relative mRNA levels of ROCK1 and ROCK2 in 33 and 40 mmol/L glucose groups were significantly increased compared with normal control group (P<0.05). Compared with normal control group, the apoptotic rate in 33 and 40 mmol/L glucose groups was increased significantly (P<0.05). Compared with normal control group, the protein expression of ROCK1, ROCK2 and cleaved caspase-3 in 33 and 40 mmol/L glucose groups was increased (P<0.05), while the protein expression of Bcl-2 was decreased (P<0.05). No significant difference in the protein levels of PI3K and Akt among the 3 groups was observed, while the protein level of p-Akt in 33 and 40 mmol/L glucose groups was decreased compared with normal control group (P<0.05). Compared with high glucose group, the expression of ROCK1 and ROCK2 was decreased in high glucose+Y27632 group. No significant difference in the protein levels of PI3K and Akt among the 3 groups was observed. Compared with normal control group, the protein level of p-Akt in high glucose group was decreased, and the protein level of p-Akt in high glucose+Y27632 group was increased significantly compared with high glucose group. CONCLUSION Under high glucose environment, ROCK may reduce the level of p-Akt by inhibiting the PI3K/Akt signaling pathway, thus promoting the apoptosis of cardiomyocytes.     

Effects of calpain-2 and autophagy-related protein 5 on hepatocyte apoptosis induced by endoplasmic reticulum stress

AIMTo investigate the effects of calpain-2 and autophagy-related protein 5 (Atg5) on apoptosis of BRL-3A rat normal liver cells during endoplasmic reticulum stress (ERS) induced by dithiothreitol (DTT). METH?ODS: BRL-3A cells were treated with DTT at 2.0 mmol/L for 0, 6, 12 and 24 h to induce ERS. Real-time cell analysis (RTCA) was used to measure the effect of DTT on BRL-3A cell proliferation. Apoptosis and cell cycle distribution were analyzed by flow cytometry. The mRNA expression of calpain-2 and Atg5 was detected by real-time PCR. The protein levels of calpain-2, Atg5, Atg7, Atg12 and microtubule-associated protein 1 light chain 3 (LC3) were determined by Western blot. The interaction between calpain-2 and Atg5 was investigated by co-immunoprecipitation (Co-IP). RESULTSThe proliferation of BRL-3A cells treated with DTT was significantly inhibited. The apoptosis of BRL-3A cells was significantly increased after DTT treatment for 6, 12 and 24 h as compared with 0 h group (P<0.05). The cell cycle was arrested in G₁ phase after DTT treatment (P<0.05). After DTT treatment for 6, 12 and 24 h, the mRNA expression of calpain-2 and Atg5 in the BRL-3A cells was significantly increased as compared with 0 h group (P<0.05). The protein levels of calpain-2, Atg12 and Atg7 in the cells treated with DTT for 6, 12 and 24 h were significantly higher than those in 0 h group, and the ratio of LC3-II/LC3-I was also significantly higher than that in 0 h group, while Atg5 expression was significantly lower than that in 0 h group (P<0.05). The results of Co-IP found that the anti-calpain-2 antibody precipitated Atg5 protein from the cell lysates, and the anti-Atg5 antibody also precipitated calpain-2 from the cell lysates, which confirmed the interaction between calpain-2 and Atg5. CONCLUSION Calpain-2 may participate in ERS-induced hepatocyte apoptosis by interacting with Atg5.