植物在水分胁迫下脯氨酸积累的研究─—Ⅳ关于植物体内脯氨酸积累的直接触发因子

依据干旱胁迫下数种植物幼苗体内游离脯氨酸、叶气孔、叶水量的变化，剖析了植物与环境因子、气孔因子、氧气因子、酶因子及能量因子之间的相互依存关系，提出了ＰＲＯ积累系统（ＰＡＳ）。认为水分胁迫下植物体内ＰＲＯ的大量积累是氧化受抑和合成受激共同调控的结果。氧气最有可能为直接触发因子。     

干旱胁迫对地被菊膜脂过氧化和抗氧化酶活性的影响

为研究地被菊的抗旱能力,用盆栽控制浇水模拟干旱的方法,研究不同程度干旱胁迫下地被菊膜脂过氧化和抗氧化酶活性的变化。结果表明:在轻度干旱胁迫下地被菊质膜透性和丙二醛含量变化不显著,随着干旱胁迫程度的加深,地被菊叶片质膜透性、丙二醛含量升高,抗氧化酶SOD、CAT活性在轻度和中度干旱胁迫下显著升高,在重度干旱条件下下降。POD活性呈现一直上升的趋势,表明地被菊有较高的抗干旱能力。     

外源甜菜碱对渗透胁迫下巴西蕉幼苗生长和生理的影响

通过叶面喷施10 mmol/L甜菜碱预处理24 h后,以100 mmol/L甘露醇灌根模拟渗透胁迫,测定巴西蕉幼苗胁迫处理不同时间后其叶片和根中的MDA含量、抗氧化酶活性、渗透调节物质含量、光合特性等生理指标,分析外源甜菜碱对渗透胁迫下巴西蕉幼苗生长和生理的作用机制。结果表明：外源甜菜碱可显著降低渗透胁迫下巴西蕉幼苗叶片和根中MDA积累量,提高巴西蕉幼苗叶片和根中SOD、POD和CAT等抗氧化酶活性,显著提高渗透调节物质可溶性糖、可溶性蛋白的合成积累量。叶片中叶绿素含量和类胡萝卜素含量都显著上升并减缓渗透胁迫下叶绿素和类胡萝卜素含量下降,显著提高渗透胁迫下叶绿素荧光参数,并减缓F_v/F_m、Y_II、ETR、Y_NPQ和Y_NO等叶绿素荧光参数的变化。因此,外源甜菜碱能有效缓解巴西蕉的渗透胁迫,提高巴西蕉的抗逆性。     

Effects of music stimulus on behavior response,cortisol level,and horizontal immunity of growing pigs

An enriched environment is widely used to improve domestic animals’ welfare and promote their natural behaviors. Music can reduce abnormal behavior in humans, nonhuman primates, and rodents. However, little is known about the effects of music on pigs. This study aims to explore the effects of repeated music stimulation on the behavior, physiology, and immunity of growing pigs. A total of 72 hybrid piglets (Large White × Duroc × Minpig) were randomly divided into three groups, including music (Mozart K.448, 60 to 70 dB), noise (recorded mechanical noise, 80 to 85 dB), and control (natural background sound, <40 dB), and 6 h sound stimulation was given per day (1000 to 1600 hours) from 40 to 100 d of age. The behavioral activities of the pigs were observed during the music stimulation, and their serum cortisol, salivary cortisol, and serum immune indices were also measured. Compared with the control group, the music group and noise group increased activity but decreased lying of pigs (P < 0.05). A significant increase in tail-wagging, playing, and exploring behaviors of pigs was found in the music group (P < 0.05), and the noise significantly increased the aggressive behavior of the pigs (P < 0.05). Tail-wagging, playing, exploring, manipulating, and aggressive behaviors decreased over time. Short-term (8 d) music stimulus had a lower cortisol level than that of the noise and control groups (P < 0.05), whereas long-term (60 d) music stimulus increased immunoglobulin G (IgG), interleukin-2 (IL-2), and interferon-gamma (IFN-γ) levels (P < 0.05) and decreased interleukin-4 (IL-4) level (P < 0.05). Long-term noise stimulus significantly reduced the level of IgG (P < 0.05) but did not affect the level of IL-2, IL-4, and IFN-γ levels (P > 0.05). In conclusion, short-term music stimulus (8 d) reduced the stress response, whereas long-term music stimulus (60 d) enhanced the immune responses. In addition, the noise increased the aggressive behavior, and long-term noise reduced the immunity of the growing pigs.     

Endogenous hydrogen sulfide regulates oxidant/antioxidant balance in rat with chronic obstructive pulmonary disease

AIM: To investigate the role of hydrogen sulfide (H₂S) in the protection against oxidative stress in rats with chronic obstructive pulmonary disease (COPD).METHODS: The rat model of COPD was established by cigarette smoking (CS) combined with lipopolysaccharide (LPS) instillation. Thirty-two healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group, CS+LPS group, CS+LPS+NaHS (H₂S donor) group and CS+LPS+PPG (DL-propargylglycine, an inhibitor of cystathionine-γ-lyase) group. After 30 days, the lung functions of the rats were measured, the histological changes of lungs were observed under light microscope and the pathological scores were calculated. The H₂S level in plasma and the protein expression of cystathionine-γ-lyase (CSE) in the lung tissues were measured. The content of malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and catalase (CAT) were detected to reflect oxidative stress.RESULTS: Compared with control group, the peak expiratory flow (PEF) decreased by 24% and intra-pressure (IP) increased by 66% in CS+LPS group. The pathological scores of the lung tissues also increased. Compared with CS+LPS group, no change in the lung function was observed after given NaHS or PPG, but the pathological scores decreased in CS+ LPS+ NaHS group. Compared with control group, the content of H₂S in plasma was increased by 26% on day 16. Compared with CS+LPS group, the content of H₂S in plasma of CS+LPS+PPG group was decreased by 22% after 30 days. Compared with control group, the protein expression of CSE increased, and no statistical difference among CS+LPS group, CS+ LPS+ NaHS group and CS+LPS+PPG group was observed. Compared with control group, MDA content in the lung tissues was increased by 24% in CS+LPS group, the activity of SOD was increased by 47% and the activity of CAT was increased by 52%. Compared with CS+LPS group, the MDA content in CS+LPS+NaHS group was decreased by 21%, and no statistical difference in the activity of SOD and CAT was observed. The activity of SOD decreased by 33% after given PPG.CONCLUSION: H₂S plays a role as anti-oxidant in the rats with COPD. The CSE/ H₂S pathway may be involved in the development of COPD.     

热应激绍兴鸭不同组织HSP70基因mRNA表达研究

研究蛋鸭热应激条件下不同组织中热休克蛋白70(HSP70)基因mRNA表达规律,为揭示蛋鸭热应激反应机理提供参考。60只绍兴蛋鸭25℃饲养20d,其中30只进行40℃热应激处理1h,采取荧光定量PCR方法分别测定不同组织中HSP70mRNA的表达水平。试验组与对照组相比,肝脏、脾脏和胰腺组织HSP70mRNA表达差异不显著,其他6种组织HSP70基因表达量均有不同程度的增加,试验组心脏、腿肌、垂体、下丘脑、胸肌、肾脏中HSP70基因表达量分别高于对照组3.6倍、2.8倍、2.7倍、2.4倍、2.2倍和1.57倍。     

月季在城市园林绿化中的应用前景

目的探索外施水杨酸和茉莉酸甲酯对盐胁迫下月季品种月月粉生理特性的影响。方法采用水培方法,对月月粉幼苗进行高盐胁迫处理、外源激素处理以及盐与激素共处理,测定处理组和对照组的叶绿素、脯氨酸和丙二醛含量以及过氧化物酶、过氧化氢酶和超氧化物歧化酶活性。结果相较于单独盐胁迫,盐胁迫下外施水杨酸和茉莉酸甲酯使月月粉叶片叶绿素含量分别提高了98.03%和80.05%,叶片中脯氨酸含量分别提高了57.23%和49.72%,根系中脯氨酸含量分别提高了56.75%和89.31%,叶片中丙二醛含量分别降低了29.92%和16.79%,根系中丙二醛含量分别降低了28.62%和20.52%。结论外施水杨酸和茉莉酸甲酯处理均可缓解盐胁迫对月月粉的伤害,且茉莉酸甲酯的缓解效果优于水杨酸。     

PEG胁迫对尖叶胡枝子幼苗SOD和POD同工酶的影响

利用聚丙烯酰胺凝胶电泳技术研究不同浓度PEG处理尖叶胡枝子幼苗叶片SOD和POD同工酶及酶活性的变化。结果表明,不同浓度PEG处理,SOD和POD同工酶谱带数目没有变化,无新酶带的出现或酶带的减少,分别为SOD1-4和POD1-3。由迁移率可以看出,尖叶胡枝子幼苗叶片在不同浓度PEG处理下,共有10种SOD同工酶基因表达和6种POD同工酶基因表达。SOD和POD酶活性在低浓度(5~10%)PEG处理下增加,高浓度(15%)的PEG处理下降低。     

DNA去甲基化参与提高白菜型冬油菜抗寒性的生理机制

利用来自不同育种环境的10份白菜型冬油菜材料,通过半致死温度的测定分析其抗寒性与环境的关系,并利用不同浓度DNA甲基化抑制剂5-azaC处理,分析DNA去甲基化对白菜型冬油菜DNA整体甲基化水平及低温胁迫下苗期生理特性的影响。结果表明,不同育种环境选育的材料,其半致死温度具有显著差异,其中材料2018-FJT、DT-7、DT-9与MXW-1的半致死温度分别为-16.04℃、-15.98℃、-15.63℃、-15.04℃;材料CT-2360、CT-2380、CT-2400、CT-2420、CT-2440、CT-2460的半致死温度分别为-11.32℃、-11.6℃、-11.42℃、-11.44℃、-12.97℃、-13.28℃。依据半致死温度,10个白菜型冬油菜抗寒性由强到弱依次为:2018-FJTDT-7DT-9MXW-1CT-2460CT-2400CT-2380CT-2420CT-2440CT-2360。抗寒性的形成与育成环境的纬度和年平均气温呈极显著正相关。选择抗寒性及产地不同的4个材料CT-2360、MXW-1、2018-FJT、DT-7进行生理测定,结果表明,1 000μmol·L~(-1) 5-azaC处理能显著抑制幼苗的根生长,4个材料的根长较对照减少93.14%～95.06%;低温下5-azaC处理对抗寒性较弱材料CT-2360幼苗的相对电导率、丙二醛含量以及强抗寒性材料DT-7幼苗的脯氨酸、可溶性蛋白含量影响最显著(P0.05);低温处理过程中,4个材料的SOD、POD、CAT活性均上升,以低温处理5d最显著(P0.05),其中2018-FJT的SOD活性增幅最高,为45.85%,DT-7的POD活性增幅最大,为460%,CT-2360的CAT活性增幅最显著,为321.02%。HPLC分析发现常温下抗寒性较弱材料CT-2360的甲基化水平为77.48%,高于其他3个抗寒性强的材料;经过5-azaC处理后发生明显的去甲基化作用,证明抗寒能力受DNA去甲基化的调控。     

饲用地衣芽孢杆菌抗逆性与益生性的体外评价

为了探讨地衣芽孢杆菌的抗逆性与益生性,研究通过5个试验评定地衣芽孢杆菌的耐高温、耐酸性、耐胆盐、抑菌性和黏附性,于85℃水浴分别处理地衣芽孢杆菌2.5 min、5 min、7.5 min模拟制粒条件;利用pH值分别为2,3,4的人工胃液模拟胃液环境;用0.3%的胆盐模拟肠液环境;抑菌试验测定地衣芽孢杆菌发酵液对大肠杆菌、金黄色葡萄球菌的抑制能力;以蛋鸡肠道上皮细胞为模型测定地衣芽孢杆菌的黏附能力。结果表明:85℃处理地衣芽孢杆菌2.5 min后活菌数最高,与对照组相比提高了2.25%(P>0.05);用pH值为2,3,4的胃液分别处理,与对照组相比活菌数分别提高0.77%(P>0.05)、1.54%(P>0.05)、1.34%(P>0.05);地衣芽孢杆菌发酵液对大肠杆菌、金黄色葡萄球菌的抑菌环直径分别为0和16.16 mm;在黏附性试验中,每100个蛋鸡肠道黏膜上皮细胞上平均可以黏附27个地衣芽孢杆菌。说明制粒过程、人工胃液、人工肠液不影响地衣芽孢杆菌的活菌数,地衣芽孢杆菌对金黄色葡萄球菌有显著抑制作用,使金黄色葡萄球菌基本不能在蛋鸡消化道内定植。