枇杷果皮响应高温强光胁迫的蛋白质组分析

为探讨枇杷[Eriobotrya japonica(Thunb.)Lindl.]果皮在高温强光胁迫下的蛋白质组分变化,采用蛋白质组学方法分析了果实日灼抗性差的枇杷种质‘WDYDB’果皮蛋白质对高温强光胁迫的应答反应。结果表明,在自然高温强光胁迫与遮光处理(对照)下,枇杷果皮蛋白质双向电泳图谱中表达量差异在2倍以上的蛋白点共有31个;通过MALDI-TOF-TOF/MS质谱分析成功鉴定出26个差异蛋白点,包括11个下调蛋白和15个上调蛋白。根据这些蛋白功能,可将其分为防御应答、碳水化合物和能量代谢、光合作用、其它等4类蛋白。同时,对这些蛋白质在高温强光胁迫下的功能和作用进行了讨论。这些差异蛋白质参与了枇杷对高温强光胁迫的响应。     

外源Ca2＋对高温强光胁迫下灌浆期小麦叶片光合机构运转的影响

灌浆期叶面喷施10mmol·L-1 CaCl2对高温强光胁迫下小麦叶片光合电子传递、放氧速率、叶绿素荧光参数和D1蛋白的影响结果表明,Ca2＋预处理可保护D1蛋白,削弱其降解,提高光系统I（PSI）和光系统Ⅱ（PSⅡ）子传递速率、全链电子传递速率、净光合速率（Pn）、PSII最大光化学效率（Fv/Fm）、PSII实际光化学效率（ΦPSⅡ）和光化学猝灭（qp）,维持较低的Fo,最终导致小麦适应高温强光的能力提高。     

高温强光胁迫下外源钙对甜椒(Capsicum fructescens L.)幼苗光合生理特性的影响

为探讨钙(Ca2+)对甜椒幼苗生长的影响,以甜椒品系156为试材,分别喷施清水(对照)、5 mmol·L-1(T5)和10 mmol·L-1Ca Cl2(T10),研究了高温(37℃)强光(1 200μmol·m-2·s-1)胁迫下甜椒幼苗叶片光合作用及叶片中活性氧(ROS)清除酶活性的变化。结果表明,高温强光胁迫条件下,与对照植株相比,外源施钙可维持较高的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)及较低的胞间CO2浓度(Ci)。甜椒幼苗功能叶在高温强光胁迫处理后,T5和T10叶片的1,5-二磷酸核酮糖羧化酶(Rubisco)活性及叶片PSII最大光化学效率(Fv/Fm)较高,表明Ca2+有利于减轻胁迫条件下甜椒幼苗叶片的光抑制现象。另外,高温强光胁迫条件下,植株叶片活性氧清除酶活性和可溶性蛋白含量明显增加,且Ca2+处理(T5和T10)的植株高于对照植株,丙二醛(MDA)含量和相对电导率则明显低于对照,这些结果均表明胁迫条件下外源施钙可以通过提高幼苗叶片ROS清除酶活性和渗透调节物质含量来保护光系统反应中心,从而减轻外界胁迫对植物的伤害。     

水杨酸对高温强光胁迫下小麦叶绿体基因psbA表达的调节

以0.1、0.3和0.5mmol.L^-1的水杨酸预处理灌浆期的小麦叶片,测定在高温强光胁迫下小麦叶绿体基因psbA表达、D1蛋白含量和PSII功能。结果表明,叶面喷施SA不仅可减缓高温强光对psbA表达的抑制,而且可促进胁迫后在适宜光温条件下恢复表达的水平。     

低温下强光胁迫对小麦叶片光系统I结构与功能的影响

探讨了低下强光胁迫对小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）扬麦５号苗期叶片（第三叶）类囊本膜上ＰＳⅠ－２００颗粒光化学特性和组分的影响。光胁迫条件下,ＰＳⅠ－２００颗粒的电子传递活性受到抑制,４℃条件下光胁迫的抑制程度低于２５℃下的抑制,２５℃条件下,光胁迫导致ＰＳⅠ－２００颗粒还原侧１９ｋＤ及ＬＨＣⅠ等多肽降解;而４℃条件下,１９ｋＤ保持稳定,但ＬＨＣⅠ等多肽在光胁迫处理过程中却发生降     

强光高温胁迫对盾叶薯蓣量子产额和77K荧光光谱的影响

以低光强生态型盾叶薯蓣(Dioscorea zingiberensis)为材料,研究强光高温(32℃)对盾叶薯蓣量子产额和77K荧光光谱的影响,以探讨强光高温胁迫与光合作用的关系.结果表明:短期高温强光胁迫引起最大量子产额显著下降,但能迅速恢复,且存在超补偿现象.强光胁迫首先破坏了光系统Ⅱ,表现为胁迫后在77K荧光光谱中出现了F680的荧光峰.670 nm红光诱导后引起部分捕光系统Ⅱ的色素蛋白转移至光系统Ⅰ,导致光系统Ⅰ的荧光发射量增加;716 nm红光诱导后引起捕光系统Ⅱ部分色素蛋白转移到光系统Ⅱ,导致光系统Ⅱ的荧光发射量增加.强光高温胁迫后各个荧光峰的差异程度减少.研究发现,强光高温胁迫引起光系统的能量重新调整,从而出现状态转变;依据F672和F675两个荧光峰的首次出现,预测叶绿体类囊体膜上含叶绿素的多肽或蛋白亚基至少有16个.     

水杨酸对高温强光下小麦叶绿体蛋白酶Deg5和PSⅡ功能的调节作用

以小麦(Triticum aestivum)矮抗58为材料,采用0.1mmol/L的外源水杨酸(SA)处理小麦叶片,以清水为对照,通过Western blotting蛋白质印记技术和叶绿素荧光分析,研究了高温强光胁迫(38℃和1600μmol m-2s-1)对小麦叶绿体Deg5蛋白酶、D1蛋白和叶绿素荧光参数的影响及SA的调节作用。结果表明,高温强光胁迫导致小麦叶绿体Deg5蛋白酶、D1蛋白含量和PSⅡ最大光能转化效率(Fv/Fm)降低,原初荧光(Fo)升高。和对照相比,外源SA处理可维持较高的Deg5蛋白酶、D1蛋白、Fv/Fm水平和较低的Fo。说明外源水杨酸可减轻高温强光对Deg5蛋白酶和D1蛋白的损伤,维持较强的PSⅡ功能。     

外源Ca2+对高温强光胁迫下滨梅幼苗的保护效应

以10 mmol/L CaCl2溶液处理滨梅幼苗叶片后,置于培养箱于(40±2)℃高温、光照强度(1 200±50)μmol·m-2·s-1下培养,定期测定有关生理生化指标,以探讨外源Ca2+对高温强光胁迫下滨梅幼苗的保护效应.结果显示:(1)与蒸馏水处理组相比,Ca2+处理使高温强光胁迫下滨梅幼苗叶片的脯氨酸含量显著升高,可溶性糖含量变化不明显,根系活力小幅降低;Ca2+处理有效抑制了高温强光下膜透性的加大,提高和保护了Ca2+-ATPase的活性.(2)采用Ca2+螯合剂EGTA或钙调素拮抗剂TFP对滨梅幼苗叶片同法处理并同条件胁迫时,与Ca2+处理相比,滨梅幼苗的脯氨酸、可溶性糖含量、Ca2+-ATPase活性和根系活力均明显下降,膜透性加大.研究表明,Ca2+处理能提高滨梅幼苗对高温强光的耐受性;Ca2+信号系统参与了胁迫过程中的渗透物质和Ca2+-ATPase活性等的调节.     

强光胁迫对濒危植物金花茶幼苗生长和叶绿素荧光参数的影响

以当年生盆栽金花茶实生苗为材料,研究不同程度的强光胁迫（25％、50％和100％自然光强,以8%自然光强为对照）对其生长、生物量、叶片光合色素含量、叶绿素荧光参数的影响。结果表明：在不同程度的强光胁迫下,金花茶幼苗的生长均受到抑制,随着胁迫程度的增强,金花茶叶片颜色由深绿变为浅绿、黄绿色,叶片灼伤愈来愈严重;植株抽稍时间推迟,抽稍后长出的新叶长势较差;幼苗死亡率越来越高。幼苗根生物量、茎生物量、叶生物量和总生物量均随胁迫程度的升高而显著降低,强光胁迫对叶生物量的影响最大,根生物量次之,对茎生物量的影响最小。随着胁迫程度的增强,叶片叶绿素总量（Chl）、叶绿素a（Chla）、叶绿素b（Chlb）含量均显著降低,Chla/Chlb和Car/Chl显著升高。叶绿素荧光参数F_o、F_m、F_v、F_v/F_m、F_v/F_o均随胁迫程度的升高降低,强光胁迫使PSⅡ受到了伤害,光合作用原初反应过程受抑制,光合电子传递受到影响,从而抑制植株的正常生长。     

银杏叶片光合作用对强光的响应

银杏叶片遭受光量子通量密度为１２００μｍｏｌｍ＾－２ｓ＾－１的强光胁迫后,净光合速率、气孔导度、细胞间隙ＣＯ２浓度、ＰＳⅡ光化学效率和表观量子效率都下降,而叶片在５０５ｎｍ处的光吸收、初始荧光水平和荧光和非光化学猝灭上升。在去除强光胁迫数小时之后,这些参数都不能完全恢复。     

利用外源多酚氧化酶酶促氧化制备茶黄素的研究

本实验选用不同的酶源，通过采用生物酶促氧化的方法制取含量较高的茶黄素粗品。研究表明，在供试的酶源中，对茶黄素的形成与积累的效果依次为：梨子〉茶叶〉苹果，利用梨子PPO制取茶黄素，其含量高达45．727％，制率也高达41．11％。而在供试的茶鲜叶中，苹云较好，槠叶齐次之，在以苹云冷冻叶为酶源制取的茶黄素含量达33．737％，制率达42．22％。     

不同品种葡萄抗霜霉病特性与叶片POD、PPO活性关系的研究

在霜霉病盛发期,对8804、梅尔诺、品丽珠3个葡萄品种(系)叶片中的PPO和POD活性变化进行了测定.结果显示,8804的PPO和POD活性较大,并保持相当长时间的高活性值,而梅尔诺、品丽珠叶片中PPO和POD活性较小;8804的PPO酶活性变化范围高于其它2个品种,但POD酶活性变化范围却低于后者.葡萄叶片中PPO和POD活性与葡萄霜霉病抗性之间存在一定的相关性,且不同抗感品种间PPO和POD酶活性存在极显著差异.研究结果表明,8804较梅尔诺、品丽珠对霜霉病具有较强的抗性.     

Effects of high temperature coupled with high light on the balance between photooxidation and photoprotection in the sun-exposed peel of apple

The sun-exposed peel of 'Gala' apple with or without sunburn was compared in terms of photooxidation and photoprotection, and a controlled experiment was conducted to probe the initial responses of PSII to high light and high temperature. The content of carotenoids, lutein and xanthophylls on a chlorophyll basis was higher in the sunburned peel although they were lower expressed on a peel area basis. Significant loss of beta-carotene and neoxanthin was observed relative to chlorophylls in the sunburned peel. O(2) evolution rates and the activity of key enzymes in the Calvin cycle were lower in the sunburned peel, but the activity of these enzymes decreased to a lesser extent than the O(2) evolution rates. The activity of antioxidant enzymes in the ascorbate-glutathione cycle and the level of total ascorbate, total glutathione, and reduced glutathione were higher in the sunburned peel. However, the sunburned peel had higher H(2)O(2) and malondialdehyde contents. Fruit peels treated with high temperature (45 degrees C) alone showed a clear "K" step in their chlorophyll fluorescence transients whereas high temperature coupled with high light (1,600 mumol m(-2) s(-1)) led to the disappearance of the "K" step and a further decrease in F (V)/F (M) (similar to what was observed in the sunburned peel). We conclude that high temperature coupled with high light damages the PSII complexes at both the donor and acceptor sides. Although both the xanthophyll cycle and the antioxidant system are up-regulated in response to the photooxidative stress, this up-regulation does not provide enough protection against the photooxidation.     

The effect of acute high light and low temperature stresses on the ascorbate–glutathione cycle and superoxide dismutase activity in two Dunaliella salina strains

Dunaliella species accumulate carotenoids and their role in protection against photooxidative stress has been investigated extensively. By contrast, the role of other antioxidants in this alga, has received less attention. Therefore, the components of the ascorbate–glutathione cycle, along with superoxide dismutase (E.C. 1.15.1.1) and peroxidase (E.C. 1.11.1.11) activity were compared in two strains of Dunaliella salina. Strain IR‐1 had two‐fold higher chlorophyll and β‐carotene concentration than Gh‐U. IR‐1 had around four‐fold higher superoxide dismutase, ascorbate peroxidase and pyrogallol peroxidase activities than Gh‐U on a protein basis. Ascorbate and glutathione concentrations and redox state did not differ between strains and there was little difference in the activity of ascorbate–glutathione cycle enzymes (monodehydroascorbate reductase [E.C. 1.6.5.4], dehydroascorbate reductase [E.C. 1.8.5.1] and glutathione reductase [E.C. 1.8.1.7]). The response of these antioxidants to high light and low temperature was assessed by transferring cells from normal growth conditions (28°C, photon flux density of 100 μmol m^?2 s^?1)to 28°C/1200 μmol m^?2 s^?1; 13°C/100 μmol m^?2 s^?1; 13°C/1200 μmol m^?2 s^?1 and 28°C/100 μmol m^?2 s^?1 for 24 h. Low temperature and combined high light‐low temperature decreased chlorophyll and β‐carotene in both strains indicating that these treatments cause photooxidative stress. High light, low temperature and combined high light‐low temperature treatments increased the total ascorbate pool by 10–50% and the total glutathione pool by 20–100% with no consistent effect on their redox state. Activities of ascorbate–glutathione cycle enzymes were not greatly affected but all the treatments increased superoxide dismutase activity. It is concluded that D. salina can partially adjust to photooxidative conditions by increasing superoxide dismutase activity, ascorbate and glutathione.     

IBA及NAA对山杜英组培苗生根过程中POD、PPO活性的影响

本文研究山杜英组培苗根诱导分化过程中过氧化物酶、多酚氧化酶活性变化。结果表明,在使用IBA和NAA后,对生根有显著影响,过氧化物酶活性在0~4d迅速下降,然后逐步上升,在根开始伸长时,活性又开始下降;不使用任何生长调节剂的情况下不生根,过氧化物酶活性在0~16d上升,然后开始下降;多酚氧化酶活性在整个根诱导中都维持在较低水平。     

培养条件对离体丹参根苯丙氨酸解氨酶和多酚氧化酶活性的影响

以2年生丹参离体根为材料,研究了反应液pH、反应时间和材料预培养时间以及苯丙氨酸、肉桂酸和阿魏酸溶液处理对根中苯丙氨酸解氨酶(PAL)和多酚氧化酶(PPO)活性的影响.结果表明:(1)PPO和PAL的最适反应pH分别为6.0和8.8,反应时间分别为30 min和60 min,最适预培养时间为10~12 h.(2)苯丙氨酸处理能抑制PAL活性,且在0.062 5 mmol·L-1时抑制作用最大,但随浓度增加无规律性变化;浓度低于1.0 mmol·L-1的苯丙氨酸处理能提高PPO的活性,且在0.062 5 mmol·L-1时促进作用最强.(3)不同浓度肉桂酸均能抑制PAL活性,并在0.125 mmol·L-1时抑制作用最大,且低浓度(≤0.125 mmol·L-1)的影响比高浓度(≥0.25 mmol·L-1)更大;低浓度肉桂酸(≤0.25 mmol·L-1)处理能提高PPO的活性并在0.25 mmol·L-1时达最大值,而在0.25~2.0 mmol·L-1浓度范围内肉桂酸对PPO活性的抑制作用随浓度的升高而增强.(4)阿魏酸对PAL表现出产物反馈抑制作用,并在0.125 mmol·L-1时抑制作用最大,但对PPO的活性有促进作用,且在0.5 mmol·L-1时PPO活性最高.可见,离体丹参根的苯丙氨酸解氨酶和多酚氧化酶活性测定有其适宜的pH、反应时间和与培养时间,苯丙氨酸、肉桂酸和阿魏酸溶液对2种酶活性的影响不同且浓度间有差异.     

7株放线菌在辣椒根部定殖及对辣椒叶片PAL与PPO活性的影响

采用盆栽接种试验、平皿涂抹法测数及常规酶活测定法研究了7株拮抗性放线菌在辣椒根部的定殖能力及接种24d对辣椒叶片苯丙氨酸解氨酶（PAl。）与多酚氧化酶活性（PPO）的诱导效应。结果表明：（1）供试7株放线菌单独接种均不能在辣椒根内定殖,但与辣椒疫霉P3混合接种时有5株可定殖;供试放线菌在辣椒根部的定殖能力与其体外平皿试验中产生的的拈抗圈大小基本无关;可定殖放线菌的定殖密度随时间延长而降低,至40d时均无活菌检出。（2）在放线菌单接处理中,5株菌接种后可诱导辣椒叶片PAL,活性提高,全部供试菌均能诱导PPO活性提高,其中可使两种酶同步提高的有5株菌;在放线菌＋P3混接处理中,有6株接种后可诱导PAL,活性提高,5株菌能诱导PPO活性提高,其中可使两种酶同步提高的有4株菌;在接入放线菌时同时混接辣椒疫霉,能增强2株供试放线菌对辣椒叶片PAL活性及6株供试放线菌对辣椒叶片PPO活性的诱导作用;供试放线菌的定殖能力与辣椒叶片PAL及PPO活性变化无明显规律性关系。     

昆虫对极端高低温胁迫的响应研究

温度是影响昆虫地理分布和扩散的重要因素之一,温度胁迫耐受性研究是昆虫生态学研究的热点之一.温度胁迫是指生物对正常生存温度之外的温度反应,包括低温胁迫和高温胁迫,它是预测害虫发生分布区、建立物候学模型、以及引入天敌的重要依据,根据昆虫温度胁迫耐受性的分化模式可预测种群的起源、分布和动态规律.本文概述了温度胁迫下昆虫的生态可塑性反应,分析了高低温交叉胁迫对昆虫抗性的影响,探讨了温度胁迫对昆虫适应性影响的内在机制,并结合国内外研究现状分析了高低温胁迫对烟粉虱Bemisia tabaci的影响,认为应从生理生化和分子生物学水平研究低温胁迫对昆虫耐受性的影响.     

Effects of long-term action of high temperature and high light on the activity and energy interaction of both photosystems in tomato plants

The acclimation to high light, elevated temperature, and combination of both factors was evaluated in tomato (Solanum lycopersicum cv. M82) by determination of photochemical activities of PSI and PSII and by analyzing 77 K fluorescence of isolated thylakoid membranes. Developed plants were exposed for six days to different combinations of temperature and light intensity followed by five days of a recovery period. Photochemical activities of both photosystems showed different sensitivity towards the heat treatment in dependence on light intensity. Elevated temperature exhibited more negative impact on PSII activity, while PSI was slightly stimulated. Analysis of 77 K fluorescence emission and excitation spectra showed alterations in the energy distribution between both photosystems indicating alterations in light-harvesting complexes. Light intensity affected the antenna complexes of both photosystems stronger than temperature. Our results demonstrated that simultaneous action of high-light intensity and high temperature promoted the acclimation of tomato plants regarding the activity of both photosystems in thylakoid membranes.