抗菌蛋白AMP对杂交竹梢枯病防治效果及其抗性相关酶活性的影响

从绛红褐链霉菌 YSSPG3发酵物中纯化获得抗菌蛋白 AMP,采用其稀释液喷雾或浸根诱导处理撑绿杂交竹苗,调查病情指数并测定杂交竹体内抗性相关酶活性的时序变化。结果表明：用抗菌蛋白 AMP(母液浓度为360.56μg·mL －1)的10,20,50倍稀释液叶片喷雾或浸根处理后,撑绿杂交竹病情指数都显著低于发病对照。经不同浓度抗菌蛋白诱导,植株内超氧化物歧化酶(SOD)、多酚氧化酶(PPO)、过氧化物酶(POD)、过氧化氢酶(CAT)和苯丙氨酸解氨酶( PAL)等抗性酶对杂交竹梢枯病菌有不同的响应。诱导并挑战接种处理的叶片内各抗性酶活性比只诱导不接种的处理上升幅度大。只诱导不接种及诱导后挑战接种,叶片内各抗性酶的活性与抗菌蛋白浓度呈正相关。POD,PPO,CAT 酶活性用浸根处理的时序变化幅度及同时期升高幅度大于喷雾处理,SOD,PAL的差异不明显。各抗性相关酶活性与病情指数的相关性分析表明,抗病性在喷雾诱导处理中与 PPO,POD 和 CAT 活性相关性显著,在浸根诱导处理中与 SOD和 PAL活性相关性显著,说明抗性酶与病情指数的变化存在内在的关联性。     

褪黑素处理对高节竹笋低温贮藏过程中木质化的影响

【目的】探讨褪黑素处理条件下,高节竹笋采后低温(4℃)贮藏过程中木质素形成、抗氧化酶活性、转录因子基因表达的变化模式,为阐明褪黑素处理对竹笋采后木质化过程的影响及其调控机制提供参考。【方法】以高节竹笋为试验材料,分析低温(4℃)贮藏过程中(0、3、6、9、12天)褪黑素(1. 0 mmol·L-1)处理组和对照组竹笋硬度、黄度、亮度,木质素、纤维素含量,木质素合成相关的苯丙氨酸裂解酶(PAL)、过氧化物酶(POD)活性,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸还原酶(APX)活性以及NAC、MYB转录因子基因表达等指标。【结果】与对照相比,外源褪黑素处理减缓笋体变硬和黄化的速度以及木质素和纤维素的积累速度,显著抑制PAL和POD活性,提高了SOD、CAT和APX活性,有效延缓高节竹笋木质化的发生进程;转录因子MYB20、MYB63、MYB85、SND2和VND7的表达随竹笋采后贮藏时间的延长均受到不同程度的诱导,而MYB42、MYB43、NST1和KNAST7的表达量则有所下降。褪黑素处理一定程度上抑制了MYB20、MYB42和KNAT7的表达,促进了MYB43、MYB63、MYB85和SND2的表达。【结论】外源褪黑素处理有效延缓了高节竹笋采后低温贮藏过程中木质化的发生进程,其机制可能是褪黑素处理降低了木质素生物合成相关酶的活性,提高了抗氧化能力。此外,褪黑素也可能参与竹笋木质化的转录调控过程。     

褪黑素浸种对盐碱胁迫下侧柏种子萌发和幼苗生长的影响

通过设置褪黑素浓度为0.1 mmol/L,盐碱浓度为50 mmol/L、100 mmol/L、150 mmol/L的不同处理，研究褪黑素浸种对不同浓度盐碱胁迫下侧柏种子萌发和幼苗生长及生理特性的影响。结果表明，与盐碱胁迫处理相比，褪黑素浸种显著提高了侧柏种子的发芽率和发芽指数，显著降低了其相对盐害率。褪黑素浸种显著降低了盐碱胁迫下侧柏幼苗的MDA含量和电导率，提高了盐碱胁迫下侧柏幼苗的根系长度、SOD活性、POD活性、游离脯氨酸含量和可溶性蛋白含量。综上所述，褪黑素可以有效缓解不同程度盐碱胁迫对侧柏种子萌发和幼苗生长的影响。     

4种诱导剂诱导杨树抗溃疡病效果的研究

选用５４０６细胞分裂素、稀土、苯硫脲和扑草净４种生物及化学物质，诱导北京杨和群众杨的离体枝条，第４ｄ结束诱导，接种病原菌ＤｏｔｈｉｏｒｅｌｌａｇｒｅｇａｒｉａＳａｃｃ。室内和田间的结果都表明，诱导后降低了发病率和病情指数。诱导的效果与诱导剂的浓度有关，浓度越大，病情指数越低。北京杨诱导后发病的潜育期延长，发病高峰推迟。     

外源褪黑素对高温胁迫下葡萄幼苗生理特性的影响

以'黑比诺'葡萄幼苗为试验材料,利用人工气候箱模拟高温环境,研究高温胁迫下外源褪黑素预处理对葡萄幼苗叶片中丙二醛MDA含量、渗透调节物质(脯氨酸、可溶性糖和可溶性蛋白)含量以及抗氧化酶(SOD、POD和CAT)活性的影响,以期探明褪黑素与葡萄耐热性之间的关系,为葡萄生产上进一步应用褪黑素提供理论指导.结果表明,高温处理...     

AXY22和苯并噻二唑的组合诱导对桉树抗病相关酶活性和丙二醛的影响

通过青枯菌无毒菌株AXY22和苯并噻二唑(BTH)诱导、接种和诱导再接种试验,研究处理后的桉树抗青枯病相关酶即过氧化物酶(POD)、多酚氧化物酶(PPO)、超氧化物歧化酶(SOD)、苯丙氨酸解氨酶(PAL)活性以及丙二醛(MDA)含量的变化。结果显示,诱接处理后桉树叶中这4种酶活性提高最大,在高峰时分别高于对照75%,85%,17%,21.6%,而MDA的含量一直在降低,5d后达到最小值,比对照低33%;诱导和接种处理后酶活性也显著提高,均高于对照;表明POD,PPO,SOD,PAL酶活性与桉树对青枯病的抗性呈正相关,而MDA呈负相关。诱导再接种处理后能够显著提高桉树对桉树青枯病的诱抗作用,这为将诱导抗性应用于桉树青枯病的防治提供了理论依据。     

水杨酸诱导山茶抗灰斑病的作用及生理生化响应

采用载玻片萌发法测定水杨酸(SA)对山茶灰斑病菌的影响。浓度为0～5mmol.L-1的SA对山茶灰斑病菌的孢子萌发没有抑制作用,其诱发抗病性可持续10～15天,诱导最佳间隔期为3天。用SA喷雾涂布叶片诱导山茶抗性,植株内丙二醛、木质素、可溶性蛋白含量等生化指标对山茶灰斑病菌诱导信号有不同响应。MDA含量在一定时间范围内减少,膜脂的过氧化程度降低,但随着处理时间的延长,这种诱导抗性的作用逐渐减弱,且在不同浓度处理间存在差异,在诱导并挑战接种的处理中,各处理表现为初期低于对照、后期缓慢上升;诱导并挑战接种的处理中,木质素含量的变化趋势与只诱导处理基本相似,高浓度诱导的木质素积累量大于低浓度;诱导并挑战接种处理的可溶性蛋白含量与只诱导处理也表现出相同的变化规律,诱导并挑战接种处理的可溶性蛋白含量比只诱导的处理和对照高。生化反应与病情指数的相关性分析表明:MDA、木质素含量与病情指数达到显著水平(P<0.05)。     

接种固氮菌对尾叶桉抗青枯病的作用及相关酶活性变化

为了明确固氮菌提高尾叶桉抗青枯病的机制,采用苗期接种固氮菌与青枯病菌的方法,测定固氮菌对桉树的促生效果,分析可溶性蛋白含量和相关防御酶的活性.结果表明,桉树苗接种联合固氮菌Kol 2个月后,接菌苗高平均达20.53 cm,比对照苗高增加了25.72%,接种固氮菌能够提高桉树苗木成活率7.34%.接种固氮菌的桉树叶片可溶性蛋白含量可以维持在一定水平,抗病相关的防御酶SOD酶、POD酶和PPO酶活性升高,酶比活力均高于接种青枯病菌和不接种对照桉树叶片酶活力.固氮菌对桉树苗有诱导抗病的作用.     

外源硼酸钠对桂花幼苗抗寒性的影响

采用人工气候室模拟低温环境,研究不同浓度的外源硼酸钠对桂花幼苗抗寒性的影响。结果显示:在4℃低温胁迫下,随时间的延长,外源硼酸钠处理桂花叶片MDA含量和可溶性蛋白含量逐渐升高,游离脯氨酸、可溶性糖含量以及SOD、CAT酶活性变化趋势为先上升后下降,POD活性持续上升;外喷0.5%~1%浓度的硼酸钠可显著减少桂花叶片MDA含量,增加游离脯氨酸,促进可溶性蛋白和可溶性糖的积累,提高SOD、POD、CAT抗氧化酶活性;0.5%浓度的硼酸钠可促进植株纵向生长,1%~2%浓度的硼酸钠对低温胁迫下桂花幼苗纵向生长产生一定的抑制作用,且浓度越高抑制性越强。低温胁迫对桂花幼苗产生一定程度的伤害,适当浓度外源硼酸钠处理可以有效缓解低温胁迫对桂花叶片的伤害,提高桂花幼苗的抗寒性。     

低温胁迫对大叶相思和马占相思某些生理特性的影响

低温处理后 ,大叶相思和马占相思叶片中可溶性糖含量、可溶性蛋白质和游离脯氨酸含量均发生明显变化。低温处理过程中超氧化物歧化酶 (SOD)活性先降低后增加 ,而膜脂过氧化的主要产物丙二醛 (MDA)则随温度的降低而呈现出先增加后减少 ,然后再增加的趋势。外源脱落酸 (ABA)预处理可显著提高马占相思的抗寒力。试验结果表明 ,以 10 - 4mol·L- 1外源ABA预处理 2 4h或 10 - 5mol·L- 1外源ABA预处理 36h对提高马占相思的抗寒力最有效     

Ionic homeostasis and reactive oxygen species control in leaves and xylem sap of two poplars subjected to NaCl stress

We investigated the effects of increasing soil NaCl concentration on intracellular compartmentalization of salt and on the activities of antioxidant enzymes (superoxide dismutase (SOD), ascorbic peroxidase (APX), catalase (CAT) and glutathione reductase (GR)) and their role in the regulation of reactive oxygen species (ROS; O(2)(-*) and H(2)O(2)) in leaves and xylem sap of salt-tolerant Populus euphratica Oliv. and salt-sensitive P. popularis cv. 35-44. Mesophyll cells of P. euphratica exhibited a high capacity for NaCl exclusion and compartmentalization of salt in vacuoles compared with P. popularis. In P. popularis, the salt treatment resulted in large accumulations of Na(+) and Cl(-) in leaves that induced significant increases in O(2)(-*) and H(2)O(2) production despite marked increases in the activities of antioxidant enzymes in leaves and xylem sap. Separation of the isoforms of leaf SOD, APX and CAT by polyacrylamide gel electrophoresis followed by in-gel activity staining revealed that the salt-induced activities of APX and CAT were the result of increases in activities of all the isoenzymes. Leaf injury and shedding of aged leaves occurred following the oxidative burst in P. popularis, indicating that the increased activities of antioxidant enzymes in P. popularis were insufficient to counter the harmful effects of ROS at high soil NaCl concentrations. Unlike P. popularis plants, P. euphratica plants did not exhibit an oxidative burst in response to the NaCl treatments, because of (1) a high salt exclusion capacity and effective compartmentalization of salt in vacuoles, and (2) up-regulation of antioxidant enzymatic activities after the onset of salt stress. We conclude that P. euphratica plants subjected to saline conditions control ROS homeostasis through two pathways: (1) by maintaining cellular ionic homeostasis and thereby limiting the NaCl-induced enhancement of ROS production under long-term saline conditions; and (2) by rapidly up-regulating antioxidant defenses to prevent oxidative damage.     

广西速生桉叶部真菌性病害的病原鉴定

通过调查并鉴定,初步探明了广西速生桉叶部真菌性病害10种,即隐盘孢叶斑病Cryptospori-opsis sp.,轮斑病Pilidiella eucalyptorum,P.diplodiella、花斑病Aureobasidium sp.、黄紫斑病Phleosporasp.、焦枯病Cylindrocladium quinqueseptatum,C.scoparium,C.floridanum、紫斑病Phaeoseptoria euca-lypti、圆斑病Pseudocercospora chiangmaiensis、灰斑病Phyllosticta lindericola、炭疽病Colletotrichumgloeosporioides、灰霉病Botrytis cinerea。前4种为我国新发现的桉树病害,Cylindrocladium floridanum是我国桉树焦枯病病原的新纪录。     

刚毛柽柳NAC24基因的表达及抗逆功能分析

【目的】NAC类转录因子是植物特有的最大的转录因子家族之一,广泛参与植物的生长发育过程,并在植物响应盐、干旱等多种非生物胁迫的过程中发挥至关重要的调控作用。本研究拟从盐生木本植物刚毛柽柳中克隆获得一个NAC转录因子基因,研究该基因的耐盐、抗旱功能,以期为研究木本植物NAC转录因子的抗逆分子机制奠定理论基础。【方法】在刚毛柽柳NaHCO_3胁迫转录组数据库中筛选获得一个NAC转录因子基因,将其命名为ThNAC24(GenBank登陆号:KF031949)。利用生物信息学工具将其与其他9个物种的NAC蛋白进行多序列比对,与拟南芥105个NAC蛋白进行进化树分析。分别用300 mmol·L^-1 NaCl和400 mmol·L^-1甘露醇对刚毛柽柳进行胁迫,在胁迫6、12、24和48 h后分别取刚毛柽柳根及叶组织。通过实时荧光定量RT-PCR(qRT-PCR)技术分析盐、干旱胁迫下ThNAC24基因在不同胁迫时间点及不同组织的表达情况,初步鉴定其是否响应盐、干旱胁迫。为进一步研究ThNAC24基因的抗逆功能,分别构建植物过表达(pROKⅡ-ThNAC24)及抑制表达(pFGC5941-ThNAC24)载体。利用农杆菌介导的高效瞬时遗传转化体系获得ThNAC24基因瞬时过表达(OE)、抑制表达(IE)及对照(Control)刚毛柽柳植株。在盐、干旱胁迫下分析比较了ThNAC24基因瞬时过表达、抑制表达及对照刚毛柽柳植株的二氨基联苯胺(DAB)和氯化硝基四氮唑蓝(NBT)染色情况,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性,及电解质渗透率、失水率及丙二醛(MDA)含量,鉴定ThNAC24基因的耐盐、抗旱功能。【结果】ThNAC24基因的开放阅读框为1 023 bp,编码340个氨基酸。多序列比对结果显示ThNAC24在N端的氨基酸序列相似度比较高,具有NAC家族的序列特征;系统进化树分析结果显示ThNAC24与ANAC103和ANAC082的亲缘关系较近。qRT-PCR结果显示:盐胁迫下,ThNAC24基因上调表达,在根组织中胁迫12 h表达量最高,而叶组织中胁迫24 h的表达量最高;干旱胁迫下,ThNAC24基因上调表达,在根组织中胁迫6 h表达量最高,在叶组织中胁迫12 h的表达量最高。ThNAC24基因在刚毛柽柳根和叶组织中均有表达且响应盐和干旱胁迫。过表达ThNAC24基因显著降低了刚毛柽柳H_2O_2和超氧阴离子含量,增强了POD和SOD酶的活性,从而减少活性氧(ROS)的积累。过表达ThNAC24基因能够降低刚毛柽柳在逆境胁迫下的电解质渗透率、失水率及MDA的积累,从而保护细胞膜结构的完整性。【结论】刚毛柽柳ThNAC24基因能够响应盐、干旱胁迫,过表达ThNAC24基因植株通过增强POD和SOD活性,进而提高ROS清除能力,减少细胞受损或死亡,从而提高刚毛柽柳的耐盐及抗旱能力。     

航华公园广玉兰煤污病的成因及无公害综合防治技术

指出了煤污病主要是由虫害引发的病害,不仅影响景观,而且容易造成植物死亡,是闵行地区较为严重的病害,分析了航华公园煤污病的成因,提出了通过修剪、刮除等多种人工措施及化学措施进行综合防治的工作,以期达到无公害防治的效果。     

出口竹制品防霉现状及其研究进展

通过调查了当前企业的防霉现状，并查阅相关文献，针对存在的问题分析探讨，拟从霉变真菌种类调查及霉变特性、防霉剂的筛选及处理方法、综合防霉措施3个方面开展研究工作。     

Effect of end-taping and removal of sapwood on radial distribution of moisture content and tangential strains during radio-frequency/vacuum drying of <Emphasis Type="Italic">Cedrela sinsensis</Emphasis> log cross sections

This study was carried out to investigate the effects of end-taping of sapwood (ETS) and removal of sapwood (ROS) treatments of log cross sections on the radial distributions of moisture content (MC) and tangential strain, according to the circumferential slicing method (CSM), during radio-frequency/vacuum (RF/V) drying of log cross sections. The MC of control and ETS samples showed an even distribution around the center but decreased closer to the periphery side. In ROS samples, the MC decreased closer to the periphery side when above the hygroscopic range but showed an even distribution at the late stage of drying. Tangential strain in ETS samples showed slight compressive stress or tensile stress through the entire area of the cross section during the initial stage of drying, although the periphery side was in tensile stress from an area starting at a relative radius of 0.7. ROS samples showed tensile stress in the heartwood around the center and the heartwood of the periphery side and showed no stress or slight compressive stress in the middle area at the initial stage of drying, after which it showed an even distribution of tensile stress throughout the entire end surface. About 90% of the total checks contained in ETS and ROS samples were observed on the periphery side starting from a relative radius of 0.7.     

Oxidative stress responses and root lignification induced by Fe deficiency conditions in pear and quince genotypes

We analysed Pyrus communis cv. Conference and Cydonia oblonga BA29, differently tolerant to lime-induced chlorosis, to identify the key mechanisms involved in their different performance under Fe deficiency induced by the absence of Fe (-Fe) or by the presence of bicarbonate (+FeBic). Under our experimental conditions, a decrease in root elongation was observed in BA29 under bicarbonate supply. Superoxide dismutase (SOD) and peroxidase (POD) activities were analysed and the relative isoforms were detected by native electrophoresis. The data obtained for both genotypes under -Fe and for BA29 +FeBic suggest the occurrence of overproduction of reactive oxygen species (ROS) and, at the same time, of a scarce capacity to detoxify them. The detection of ROS (O(2)(-) and H(2)O(2)) through histochemical localization supports these results and suggests that they could account for the modifications of mechanical properties of the cell wall during stress adaptation. On the other hand, in the cv. Conference +FeBic, an increase in non-specific POD activity was detected, confirming its higher level of protection in particular against H(2)O(2) accumulation. Peroxidases involved in lignification were assayed and histochemical analysis was performed. The results suggest that only in BA29 under bicarbonate supply can the presence of ROS in root apoplast be correlated with lignin deposits in external layers and in endodermis as a consequence of the shift of PODs towards a lignification role. We suggest that in BA29 the decrease in root growth could impair mineral nutrition, generating susceptibility to calcareous soils. In the cv. Conference, the allocation of new biomass to the root system could improve soil exploration and consequently Fe uptake.     

核桃果皮对苹果蠹蛾为害的防御响应

目的 研究苹果蠹蛾为害后诱导核桃果皮产生的防御应答响应。 方法 采用紫外分光光度法与酶标仪微量法分析核桃果皮营养物质、次生代谢物质的含量,防御酶的活性以及苹果蠹蛾与核桃的互作关系。 结果 核桃果皮被苹果蠹蛾蛀食后可溶性糖与可溶性蛋白的含量随着时间推移逐渐降低,在为害24 h时可溶性蛋白含量与对照相比差异显著（P<0.05）;在为害48 h时可溶性糖与对照相比差异显著（P<0.05）。次生代谢物质胡桃醌、单宁的含量随时间的推移呈先上升后下降的趋势,其中胡桃醌在为害48 h时含量达到最高,为976.68 µg·g−1,是对照的1.44倍;单宁含量在24 h时达到高峰,为4.11 mg·g−1,是对照的1.33倍;类黄酮的含量呈逐渐上升趋势,在24 h时与对照相比差异显著（P<0.05）。在为害12 h时,CAT活性与对照相比差异显著（P<0.05）,在72 h时CAT活性达峰值,为55.97 U·min−1·g−1,是对照的1.45倍;POD活性呈先下降后上升的趋势,在72 h时达最高值,是对照的1.62倍;SOD活性呈先上升后下降的趋势,在24 h时达到峰值,为623.69 U·g−1,是对照的1.98倍。 结论 核桃果皮主要通过调节体内的营养物质、次生代谢物质以及防御酶活性的变化,对苹果蠹蛾的为害产生应激反应,进而发挥防御作用。     

毛白杨幼苗抗氧化系统对盐胁迫的响应

在 3种不同浓度的NaCl (85mmol·L-1,170mmol·L-1,2 6 0mmol·L-1)胁迫下 ,对毛白杨幼苗的超氧化物歧化酶 (SOD)和过氧化物酶 (POD)活性以及丙二醛 (MDA)含量进行测定 .结果发现 ,在NaCl胁迫 3小时后 ,幼苗SOD和POD活性显著降低 ,随着胁迫时间的延长 ,这两种酶活性降低较缓慢 ,但SOD活性下降程度均较POD小 .在NaCl胁迫中 ,MDA含量明显增加 ,并于胁迫 15小时后达到最大值 ,随后含量增加较小 .进一步分析发现 ,不同浓度NaCl处理对SOD和POD活性以及MDA含量的作用效应是不同的 ,其中 2 6 0mmol·L-1NaCl处理明显促进幼苗SOD和POD活性的下降与MDA含量的增加 ;而且MDA含量与SOD和POD活性的下降有关 .结果表明 ,NaCl胁迫所引起的SOD和POD活性下降可能加强膜脂过氧化作用 ,最终导致幼苗MDA含量的增加与伤害的发生     

Over expression of TaFer gene from Tamarix androssowii improves iron and drought tolerance in transgenic Populus tomentosa

Ferritin, a universal intracellular protein, can store large amounts of iron and improve plant resistance to abiotic and biotic stress. In this study, a ferritin gene(TaFer) from Tamarix androssowii Litv. was transferred into Populus tomentosa Carr. cv 'BJR01' via Agrobacterium. Six independent transgenic lines were obtained with a tolerance to kanamycin and three were randomly selected for further analysis. The PCR and RT-PCR results indicate that the TaFer gene had been integrated into the poplar genome. The effect of the gene on abiotic stress tolerance was tested, and the results show that transgenic plants improve growth, had higher chlorophyll and lower MDA contents, and higher relative electrical conductivity,fewer changes of SOD and POD activities, higher iron content, higher root ferric reductase activity and lower levels of ROS accumulation and cell death in response to drought, Fe-insufficient or Fe-excess tolerance. These results indicate that the TaFer gene can improve abiotic stress tolerance in transgenic Populus tomentosa.