Divergent functions of SNAC4–9 and possible mechanisms for tomato adaptation to abiotic stresses

Plants are exposed to all types of abiotic stresses during the process of growth and development, which could adversely affect the productivity and postharvest storage quality of plants. In the current study, the expression of SNAC4–9 and the changes of physiological parameters were analyzed in tomato seedlings under various abiotic conditions and hormone treatments. The results demonstrate that all six genes were induced by these stresses at differential induction levels and that SNAC4–9 gene expression profiles were likely to be related to the ABA, SA, and MeJA signaling pathways. In addition, all of the stress- and hormone-treated seedlings exhibited significant increases in their proline content and antioxidant enzyme activities. MDA was significantly increased in seedlings exposed to stress and decreased in hormone-treated seedlings. These data collectively suggest that SNAC4–9 might function through ABA, SA, and JA signaling pathways and the regulation of proline and antioxidant systems. This study combines molecular biology and physiology to provide valuable information for further exploring the functional roles of NAC genes in response to environmental stresses and indicates that these genes may exhibit potential for enhancing stress tolerance of transgenic tomato plants and further improving the postharvest storage quality of tomato plants.     

3种核桃青皮提取物对玉米螟中肠酯酶活性的影响

通过核桃青皮馏分3、6与核桃青皮萃取物青甲水对玉米螟幼虫进行了室内毒力测定,以及中肠酯酶离体活性测定,结果表明核桃青皮馏分6对玉米螟5龄幼虫有较强地抑制作用,青甲水对中肠酯酶的抑制作用不显著。     

青海省几种藏药植物资源状况调查与分析

为有效保护野生植物资源,对产自青海省西宁市、海东市、海北州、海南州、黄南州、果洛州、玉树州和海西州的麻黄、大黄、秦艽、贝母等4种植物的分布区、分布面积、适生环境、资源储量等开展调查研究,并就其资源利用潜力、资源受威胁状况等进行了评价分析。结果表明:麻黄、大黄、秦艽应予以控制,酌量利用;贝母应严加保护,保存种源;麻黄为濒危种类,亟待加以保护;大黄、秦艽、贝母为渐危种类,应重点加以保护。     

葡萄籽粉对保加利亚乳杆菌生长的影响研究

以葡萄籽粉为试验材料,以菊芋粉为对比材料,研究葡萄籽粉在牛乳中对保加利亚乳杆菌生长的影响,以期为进一步开发和、研制抗氧化酸奶提供理论依据。结果表明,在牛乳中加入葡萄籽粉,凝乳时间有所缩短,葡萄籽粉对保加利亚乳杆菌生长无抑制作用,3．0％葡萄籽粉添加量对保加利亚乳杆菌生长有显著促进作用。     

Adaptive immune response of Vgamma2Vdelta2+ T cells during mycobacterial infections

To examine the role of T cell receptor (TCR) in gammadelta T cells in adaptive immunity, a macaque model was used to follow Vgamma2Vdelta2+ T cell responses to mycobacterial infections. These phosphoantigen-specific gammadelta T cells displayed major expansion during Mycobacterium bovis Bacille Calmette-Guérin (BCG) infection and a clear memory-type response after BCG reinfection. Primary and recall expansions of Vgamma2Vdelta2+ T cells were also seen during Mycobacterium tuberculosis infection of naive and BCG-vaccinated macaques, respectively. This capacity to rapidly expand coincided with a clearance of BCG bacteremia and immunity to fatal tuberculosis in BCG-vaccinated macaques. Thus, Vgamma2Vdelta2+ T cells may contribute to adaptive immunity to mycobacterial infections.     

《华南热带农业大学学报》的信息密度及其经济分析

分析2002年《华南热带农业大学学报》的信息密度及其对年直接费用支出的影响。结果表明：其信息密度较小。每条科技信息传递的费用较高。提出编辑部应自行排版以更合理设计版面，加强编辑人员的培训以提高编辑技能。建议刊物信息密度控制在0.25篇／页。     

不同日粮对育肥滩羊屠宰性能和挥发性风味物质的影响

试验旨在研究舍饲滩羊育肥羊的饲喂模式下,颗粒饲料对肉羊屠宰性能和挥发性物质的影响。试验选择体重相近的70日龄宁夏滩羊羯羊45只,随机分为3组,每组15只。对照组饲喂养殖场自配全混合日粮、试验I组饲喂TMR颗粒料、试验II组饲喂颗粒化精料补充料及草料颗粒料。试验期87 d。结果显示:试验I组的宰前活重极显著高于对照组(P<0.01),试验II组的宰前活重极显著低于对照组(P<0.01),试验I组的胴体重极显著高于对照组和试验II组(P<0.01),试验II组小肠活重比显著高于对照组和试验I组(P<0.05)。3组试验羊背腰最长肌均检测出59种挥发性物质,其中烷烃26种,对照组烷烃类物质相对含量较高(36.87%);醛类化合物11种,试验I组相对含量较高(36.88%);杂环烷、脂类、醇类和酸类化合物分别检测出6种、6种、8种和2种。研究表明,在羔羊育肥期,选用育肥羊全混合颗粒料能够更好地改善肉品香味。     

热处理对轻度加工葡萄膜脂过氧化作用的影响

为探索热处理对轻度加工葡萄衰老软化及贮藏保鲜效果的影响，以红地球葡萄为试验材料,研究了50℃ 10 min、50℃ 15 min、 55℃ 5 min、55℃ 10 min热空气处理对其衰老过程中膜脂过氧化作用及贮藏效果的影响。结果表明，55℃ 5 min和10 min处理与对照相比，能抑制过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性的下降，降低丙二醛(MDA)含量的积累和果肉组织的相对电导率，从而抑制轻度加工葡萄的衰老软化。而50℃ 10 min和15 min热处理对延缓轻度加工葡萄衰老软化无明显作用。     

有机生活垃圾半干发酵菌群的分布变化特征

为了研究有机生活垃圾厌氧发酵中菌群的分布变化特征,以有机生活垃圾为生物质资源,进行半干式厌氧发酵试验。采用最大或然数法(most probable number,MPN)分析发酵过程中厌氧菌群时间和空间上的数量变化。结果表明:厌氧菌中产酸菌先于氨化菌达到最大值并占据优势地位,产甲烷菌在启动阶段初期基本没有增殖,第25天左右达到最大值3.2×109个/m L,随后产甲烷菌在整个盛产期数量维持在这一数量级上。厌氧纤维素降解菌菌数呈现缓慢增长的趋势,直到投料的第45天才增加到106个/m L。空间上厌氧产酸菌和甲烷菌的数量均是在基质条件稳定的中部位置和流动性较好的底部位置较多;厌氧氨化菌数量较多的为中部边缘和中部中心位置;厌氧纤维素降解菌主要在底部增殖。初步构建了产酸菌与产甲烷菌时间和空间的动力学模型,模型拟合效果良好,可为厌氧发酵工艺提供参考。该文对有机垃圾制取生物燃气的工艺过程具有理论指导意义。     

Comparison of HPLC methods for determination of anthocyanins and anthocyanidins in bilberry extracts

An HPLC method and an acid hydrolysis HPLC method for the analysis of anthocyanins and anthocyanidins in bilberry extracts have been developed. The HPLC method coupled with a mass detector has identified 11 anthocyanins in bilberry extracts. The method provides anthocyanin profiles that are very useful in verifying the identity of botanical raw materials, monitoring the consistency of the raw material source, and quantitating the total anthocyanins. The acid hydrolysis HPLC method greatly simplifies the anthocyanin profile in bilberry samples and converts anthocyanins to five major anthocyanidin aglycones: delphinidin, cyanidin, petunidin, peonidin, and malvidin. Each of these aglycones can be separated completely and quantitated accurately with external standards. Various extraction and hydrolysis conditions were investigated, and the advantages and disadvantages of the HPLC and acid hydrolysis methods are discussed.