昆虫发育与免疫：现代昆虫学一个重要方向

昆虫发育与免疫作为昆虫学的重要方向,面向国家需求和科学前沿,经过多维度的研究,在解决重大害虫成灾和人类健康等方面取得了重要成就。同时,生物技术的进步极大地推进了昆虫发育与免疫的学科发展,使得我们对昆虫生长发育和免疫防御的认识更加深入和全面。本“昆虫生长发育与免疫”专辑论文较好地反映了我国昆虫发育与免疫的研究现状与研究特色。生长发育方面涵盖了从卵到成虫的所有发育阶段,主要研究信号转导机制;免疫方面则聚焦于生物互作。在大数据背景下,将传统和现代技术并用,加强合作,使本研究方向在害虫防治、昆虫资源利用和粮食安全等方面将发挥更大的作用。     

多次交配对小菜蛾精包形成与生殖力的影响

【目的】小菜蛾Plutella xylostella是主要为害十字花科作物的一种世界性害虫,强大的生殖能力是其成为田间最难防治的害虫的主要原因之一。交配是营两性生殖昆虫繁衍后代必要的一个生理过程,明确小菜蛾雌雄成虫的交配行为及交配后的生理响应,对于小菜蛾种群监测和综合防治具有重要意义。【方法】解剖观察小菜蛾成虫生殖腺及精包形成;利用行为学与生物学实验,测定和分析小菜蛾成虫交配与再交配能力、精包形成与消化,以及交配次数对精包形成以及雌虫生殖力的影响。【结果】小菜蛾雄成虫在交配过程中精液以精包的形式传递给雌成虫,在交配囊中精包呈白色、不透明、气球状结构,交配结束后精包可被充分消化和吸收。成虫交配能力观测结果显示,小菜蛾雌雄成虫均具有多次交配行为。首次交配后,雄成虫表现出短暂的再交配延迟,20 min内其交配成功率为54.6%,显著低于首次交配。虽然交配次数不会影响雄成虫的交配时长,但雄成虫交配史对其自身的精包大小以及雌成虫的生殖力均具有显著的抑制作用。雌成虫表现出明显的再交配抑制性,交配过的雌成虫在12 h内的交配率显著低于未交配雌成虫的,这可能取决于首次交配后精包的消化和吸收速率。雌成虫多次交配后,其产卵量和卵孵化率与单次交配的相比没有显著差异。【结论】多次交配会使小菜蛾雄成虫再交配延迟,雌成虫再交配受到抑制;多次交配产生的雄成虫精包显著减小,雌成虫产卵量与卵孵化率并没有从多次交配中获得收益。本研究为解析小菜蛾雌雄成虫生殖调控机制奠定理论基础。     

鹿衔草内生真菌Penicillium solitum次生代谢产物的分离鉴定与神经保护活性筛选

【背景】鹿衔草(Pyrola incarnata Fisch)化学成分丰富,而且具有多种药理活性,在食品、医药领域得到广泛应用,但尚未见其内生真菌次生代谢产物的相关报道。【目的】对鹿衔草内生真菌Penicillium solitum (P.solitum)的次生代谢产物进行分离鉴定,筛选出具有抗神经炎症的活性成分。【方法】采用柱层析和制备型高效液相色谱对鹿衔草内生真菌P.solitum次生代谢产物进行分离和纯化,通过核磁共振和高分辨质谱进行结构鉴定,利用反向分子对接技术筛选出抗神经炎症活性的化合物,采用脂多糖(lipopolysaccharide,LPS)诱导的BV-2细胞炎症模型进行验证。【结果】从鹿衔草内生真菌P.solitum次生代谢产物中分离鉴定出12个化合物,分别为cyclopenin (1)、dehydrocyclopeptin (2)、viridicatin (3)、对羟基苯甲酸(4)、吲哚乙酸(5)、methyl compactin (6)、cyclopeptine (7)、cyclopenol (8)、原儿茶酸(9)、viridicatol (10)、N-[2-(3-indolyl) ethyl]malonamic acid (11)和solitumidine A (12)。分子对接结果显示化合物11与炎症相关的丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)信号通路中p38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,简称p38)和细胞外信号调节激酶1(extracellular regulated protein kinase 1,ERK1)有较高的结合活性。BV-2细胞实验表明,化合物11 (10、20μmol/L)能显著提高BV-2细胞存活率,并有效抑制炎症因子(肿瘤坏死因子-α、白介素-1β、白介素-6)和一氧化氮的释放。【结论】化合物11是新天然产物,具有抗神经炎症活性,其作用机制可能与抑制MAPK信号通路中p38和ERK蛋白的表达有关。     

TAL effector-dependent Bax gene expression in transgenic rice confers disease resistance to Xanthomonas oryzae pv. oryzae

The hypersensitive response (HR) is a form of programmed cell death of plant cells occurring in the local region surrounding pathogen infection site to prevent the spread of infection by pathogens. Bax, a mammalian pro-apoptotic member of Bcl-2 family, triggers HR-like cell death when expressed in plants. However, constitutive expression of the Bax gene negatively affects plant growth and development. The Xa10 gene in rice (Oryza sativa) is an executor resistance (R) gene that confers race-specific disease resistance to Xanthomonas oryzae pv. oryzae strains harboring TAL effector gene AvrXa10. In this study, the Xa10 promoter was used to regulate heterologous expression of the Bax gene from mouse (Mus musculus) in Nicotiana benthamiana and rice. Cell death was induced in N. benthamiana after co-infiltration with the P_Xa10:Bax:T_Xa10 gene and the P_PR1:AvrXa10:T_Nos gene. Transgenic rice plants carrying the P_Xa10:Bax:T_Xa10 gene conferred specific disease resistance to Xa10-incompatible X. oryzae pv. oryzae strain PXO99^A(pHM1AvrXa10), but not to the Xa10-compatible strain PXO99^A(pHM1). The resistance specificity was confirmed by the AvrXa10-dependent induction of the P_Xa10:Bax:T_Xa10 gene in transgenic rice. Our results demonstrated that the inducible expression of the Bax gene in transgenic rice was achieved through the control of the executor R gene promoter and the heterologous expression of the pro-apoptosis regulator gene in rice conferred disease resistance to X. oryzae pv. oryzae.

     

云南省普洱市思茅区路杀爬行动物研究

爬行动物是受道路影响的主要野生脊椎动物类群之一,2019-2020年,采用路巡调查法对云南省普洱市思茅区爬行动物路杀现象进行了调查。结果发现,路杀爬行动物有7科22种100只,钝头蛇科的横纹钝头蛇Pareas margaritophorus、眼镜蛇科的银环蛇Bungarus multicinctus是路杀数量最多的物种,包括2种国家二级重点保护野生动物：闪鳞蛇Xenopeltis unicolor和三索蛇Coelognathus radiatus。爬行动物的路杀有3个高峰时间段,7：00-10：00时是最集中的路杀时间段。温度20-25℃是最集中的路杀温度范围。进一步的分析发现,爬行动物的路杀与其活动节律有关,7：00-10：00时的晒阳行为可能是路杀的主要诱因。     

三峡水库涪陵-奉节段消落带优势草本植物生态位与种间联结性研究

参照相邻格子法对三峡水库中段(重庆市涪陵—奉节段消落带)地上植被进行调查,并运用生态位宽度、生态位重叠度、χ~2检验等手段对优势草本植物生态位与种间联结性进行分析,能在一定程度上揭示三峡水库消落带优势草本植物的生态学特性、进而推测植被群落的演替趋势,以期为三峡水库消落带植被生态修复提供理论基础或参考建议。结果表明：(1)本次调查发现共有优势植物57种、隶属22科44属,其中狗牙根的生态位宽度最大、占绝对竞争优势。(2)在105个种对中,生态位相似比(C_ih)≥0.50的种对有4个,生态位重叠值(L_ih)≥0.50的种对有7个,种间相似性较小、竞争关系较弱。(3)χ~2检验结果显示,优势植物种间正负联结比为1.33,正联结优势不明显;而Pearson与Spearman秩相关检验结果显示,种间正负联结比分别为0.54、0.75,负联结占优势。三种检验方式均表明,优势植物种间联结性较弱、稳定性相对较差、独立性相对较强。(4)种间联结系数(AC)≥0.60的种对数为7种,共同出现百分率(PC)≥0.7的种对数仅为1种。种间总体正联结性不强,物种趋于独...     

基于GIS的四川盆周北部山区夏玉米农业气象灾害风险评估——以旺苍县为例

气象灾害是制约我国农业发展的主要因素之一,明确夏玉米农业气象灾害风险对于防灾减灾具有重要意义。本研究基于自然灾害风险理论,以四川盆地北部山区的典型区域(旺苍县)1981—2018年气象数据和玉米产量数据为基础,确定影响夏玉米生产的主要致灾因子,并结合孕灾环境敏感性及承灾体脆弱性构建夏玉米综合农业气象灾害风险评估模型,对四川盆地北部山区夏玉米生产过程中的农业气象灾害风险进行评估。结果表明: 研究期间,成熟期高温、花期暴雨、成熟期暴雨、灌浆期连阴雨和孕穗期干旱是影响研究区夏玉米生长发育的主要农业气象灾害。旺苍县夏玉米农业气象灾害综合风险分布大致呈西南-东北走向,高风险和较高风险区分布区域约占旺苍县总面积的二分之一;灾害风险高值区主要位于研究区西南部,基本与致灾因子危险性高值区一致;灾害风险低值区多集中在西部边缘,此区域亦为成熟期高温、成熟期暴雨、花期暴雨气象灾害的低风险区。     

女贞子化学成分、药理作用及药动学研究进展

女贞子系木犀科(Oleaceae)女贞属植物女贞(Ligustrum lucidum)的干燥果实,为我国传统中药,具有滋补肝肾、明目乌发的功效。女贞子含三萜类、环烯醚萜类、苯乙醇苷类及黄酮类等多种化学成分。许多药理作用研究表明女贞子具有抗肿瘤、抗氧化、抗炎镇痛、保肝、抗骨质疏松、免疫调节、降血糖降血脂、抗菌抗病毒等活性。对女贞子的化学成分、药理作用及药代动力学研究进行综述,以期为我国女贞子资源的进一步开发和利用提供参考。     

Betulinic acid induces apoptosis and suppresses metastasis in hepatocellular carcinoma cell lines in vitro and in vivo

Hepatocellular carcinoma (HCC) is a high incidence and mortality malignant tumour globally. Betulinic acid (BA) is a pentacyclic triterpenoid with potential pro‐apoptotic activities which widely found in many plants. In this study, we determined the effects of BA on proliferation, apoptosis, invasion, and metastasis in HCC cell lines and on tumour growth and pulmonary metastasis in mice. The results suggested that BA could inhibit cell viability and proliferation of HCC cell lines including HepG2, LM3, and MHCC97H. In addition, BA induced apoptosis of HepG2 cells characterised condensed nuclei and nuclear fragmentation. Moreover, western blot analysis showed that BA‐induced apoptosis associated with increasing of pro‐apoptotic protein Bax and cleaved caspase‐3 and decreasing of anti‐apoptotic protein Bcl‐2. Meanwhile, BA also reduced the reactive oxygen species (ROS) level. Furthermore, BA also significantly inhibited HCC growth in vivo and blocked pulmonary metastasis of HCC by regulating the metastasis‐related proteins including MMP‐2, MMP‐9, and TIMP2 without obvious toxicity. In all, the present study suggested that BA might be a promising anti‐HCC drug candidate by inhibiting proliferation, inducing apoptosis, and blocking metastasis.     

Removal of nitrogen by heterotrophic nitrification–aerobic denitrification of a novel halotolerant bacterium Pseudomonas mendocina TJPU04

Excess inorganic nitrogen in water poses a severe threat to enviroment. Removal of inorganic nitrogen by heterotrophic nitrifying–aerobic denitrifying microorganism is supposed to be a promising and applicable technology only if the removal rate can be maintained sufficiently high in real wastewater under various conditions, such as high concentration of salt and wide range of different nitrogen concentrations. Here, a new heterotrophic nitrifying–aerobic denitrifying bacterium was isolated and named as Pseudomonas mendocina TJPU04, which removes NH₄⁺-N, NO₃⁻-N and NO₂⁻-N with average rate of 4.69, 5.60, 4.99 mg/L/h, respectively. It also maintains high nitrogen removal efficiency over a wide range of nitrogen concentrations. When concentration of NH₄⁺-N, NO₃⁻-N and NO₂⁻-N was up to 150, 150 and 50 mg/L, 98%, 93%, and 100% removal efficiency could be obtained, respectively, after 30-h incubation under sterile condition. When it was applied under non-sterile condition, the ammonia removal efficiency was slightly lower than that under sterile condition. However, the nitrate and nitrite removal efficiencies under non-sterile condition were significantly higher than those under sterile condition. Strain TJPU04 also showed efficient nitrogen removal performance in the presence of high concentration of salt and nitrogen. In addition, the removal efficiencies of NH₄⁺-N, NO₃⁻-N and TN in real wastewater were 91%, 52%, and 75%, respectively. These results suggest that strain TJPU04 is a promising candidate for efficient removal of inorganic nitrogen in wastewater treatment.