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1.
钠盐和钙盐胁迫对草莓光合作用的影响   总被引:9,自引:0,他引:9  
以草莓(Fragaria ananassaDuch.)达塞莱克特品种为试材,采用盆栽法研究了NaCl、CaCl2、Ca(AC)2和Ca(NO3)2胁迫对其生长及光合特性的影响.结果表明,4种盐胁迫下草莓的生物产量、叶绿素含量、净光合速率、蒸腾速率和气孔导度显著降低,且盐浓度越高,下降幅度越大.其中,净光合速率、蒸腾速率和气孔导度的降幅由大到小依次为:Ca(AC)2>Ca(NO3)2>CaCl2>NaCl.与对照相比,NaCl胁迫下草莓根冠比减小,而钙盐胁迫下草莓的根冠比增大,且各盐处理内均随盐浓度增加而增大.钙盐胁迫对草莓光合作用的影响大于钠盐,其中,NaCl胁迫对植株的伤害最小,Ca(AC)2处理的伤害最大.  相似文献   

2.
渗透胁迫下小麦根及叶片中ABA含量增加,根部先于叶片,同等渗透胁迫条件下,外源Ca2 浓度越小,根中ABA含量增加越多。EGTA和TFP浓度越大,ABA合成越早,且含量越高。  相似文献   

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一氧化氮参与调节盐胁迫诱导的玉米幼苗脱落酸积累   总被引:12,自引:1,他引:11  
以三叶一心期的玉米幼苗为实验材料,研究了盐胁迫下玉米幼苗根尖和叶片中一氧化氮(NO)和脱落酸(ABA)积累之间的关系。结果表明,盐胁迫下玉米幼苗NO和ABA的含量均增加,用NO供体硝普钠(Sodium nitroprusside,SNP)处理时,ABA含量亦增加,且累积的时间较盐胁迫下早。用NO合成的抑制剂L-NAME (Nω-nitro-L-arginine methyl ester hydrochloride)和NaN,处理时,可减弱盐胁迫诱导的ABA含量的增加,用NO清除剂cPTIO处理时,这种盐胁迫诱导的ABA增加减少。推测盐胁迫下产生的NO参与调节ABA的积累及逆境下植物的防御反应。  相似文献   

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以番茄品种'农城906'和"毛粉802'幼苗为材料,利用Hoagland基础培养液,研究在150 mmol/L NaCl胁迫下外源10、20、30和40 mmol/L Ca(NO3)2对番茄植株盐胁迫的缓解作用.结果显示,(1) NaCl胁迫显著降低了2个品种幼苗地上和地下部分干重、叶片叶绿素含量和根系活力,增加了幼苗的可溶性糖含量、细胞膜透性和MDA含量,同时使其CAT、POD、SOD活性显著降低;(2)添加20 mmol/L Ca(NO3)2能够有效提高盐胁迫条件下幼苗的地上和地下部干重,缓解叶绿素的降解和根系活力的下降,增加幼苗体内可溶性糖含量,降低叶片质膜透性和MDA含量,增强幼苗体内POD、CAT等细胞保护酶活性,但随着Ca(NO3)2浓度的继续增加,这种缓解作用逐渐减小.研究表明,一定浓度的外源Ca(NO3)2能有效缓解NaCl对番茄幼苗的生长和生理伤害,在一定程度上增强番茄幼苗对盐胁迫的耐受力,并以20 mmol/L Ca(NO3)2对NaCl胁迫的缓解效果最佳.  相似文献   

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等渗盐胁迫对番茄抗氧化酶和ATP酶及焦磷酸酶活性的影响   总被引:19,自引:0,他引:19  
用Ca(NO3)2 80 mmol/L和NaCl 120 mmol/L等渗溶液处理番茄幼苗后,细胞质和叶绿体中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)的活性升高,并且NaCl胁迫的作用明显高于Ca(NO3)2胁迫.Ca(NO3)2处理提高了线粒体中SOD、CAT、APX的活性,而NaCl处理降低了它们的活性.根系质膜H -ATPase、液泡膜H -ATPase、焦磷酸酶(H -PPase)的活性和叶片丙二醛(MDA)及脯氨酸含量在两种盐胁迫后明显增加.NaCl处理对植株生长的抑制程度明显高于Ca(NO3)2处理.  相似文献   

6.
外源GA3、ABA和Ca(NO3)2缓解盐对小麦种子萌发的抑制作用   总被引:19,自引:3,他引:16  
盐胁迫下,DK961(耐盐)和LM15(盐敏感)小麦种子的发芽率(Gr)、发芽指数(Gi)和活力指数(Vi)均显著下降,LM15下降的幅度大于DK961.外源100 mg/L GA3、1×10-7 mol/L ABA和0.1% Ca(NO3)2处理均能缓解盐对小麦种子萌发的抑制作用,对盐胁迫下LM15种子萌发的缓解作用显著好于DK961,并且不同程度地缓解盐处理引起的种子内源GA 1+3含量和α淀粉酶的活性下降,从而降低盐胁迫对种子萌发的抑制作用.表明盐抑制小麦种子萌发的主要原因是盐胁迫导致种子内源GA 1+3含量和α淀粉酶的活性下降.  相似文献   

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黄瓜花期高温胁迫对叶片衰老特性和内源激素的影响   总被引:2,自引:0,他引:2  
为了研究黄瓜花期高温胁迫对植株叶片衰老特性及内源激素的影响,本研究以黄瓜‘南杂2号’(Nan ZaⅡ)品种为试材,利用人工气候箱设计3个温度处理:昼温/夜温分别为36℃/26℃、39℃/29℃、42℃/32℃,以昼温/夜温24℃/18℃为对照(CK),持续时间设计1、3、5和7 d。处理完成后分别测定黄瓜叶片叶绿素含量、抗氧化酶活性、MDA含量和顶芽内源激素含量。结果表明:42℃/32℃处理7 d时黄瓜叶片叶绿素a、叶绿素b、类胡萝卜素含量,POD、SOD活性,顶芽IAA、GA3、ZT含量分别较CK降低了16.61%、23.17%、73.33%、17.89%、56.90%、94.16%、54.32%、90.68%;而叶片MDA含量、CAT活性和顶芽ABA含量分别较CK增加了62.66%、28.06%和294.35%;短期高温胁迫增加了黄瓜叶片的叶绿素含量,随着温度的升高,胁迫时间的延长叶片叶绿素b含量逐渐降低;短期高温胁迫增加了叶片抗氧化酶活性,随着高温胁迫的加剧,抗氧化酶活性表现出逐渐降低的趋势;高温胁迫下黄瓜顶芽ABA含量表现出增加的趋势,而IAA、GA3和ZT含量的变化则相反。本研究揭示了黄瓜花期高温胁迫下叶片衰老特性和内源激素含量的变化规律,为黄瓜栽培的温度管理提供科学依据。  相似文献   

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内为了解香蕉幼苗叶片结构和生理情况,采用在人工模拟盐胁迫环境下,利用EGTA(Ca~(2+)螯合剂)、TFP(CaM拮抗剂)、LaCl_3(Ca~(2+)通道阻碍剂)、外源Ca~(2+)等试剂来阻碍或增强巴西蕉和粉蕉幼苗钙信号转导途径,测定两个不同品种香蕉幼苗叶片的相对含水量、叶绿素含量以及质膜透性,同时通过制作石蜡切片对叶片解剖结构进行了观察。结果表明,盐胁迫下,EGTA、TFP、LaCl_3等钙信号阻碍剂处理使巴西蕉和粉蕉叶片相对含水量、叶绿素含量显著降低,且使其质膜透性显著增加,加剧了叶片组织结构破坏,盐伤害加重,而粉蕉抗性强于巴西蕉,其抗性更敏感,但在盐胁迫下,外源钙能维持细胞外形促使香蕉幼苗叶片正常,使盐胁迫的伤害得到缓解。说明钙信号系统对外源钙缓解盐胁迫对香蕉叶片的伤害有重要的影响。  相似文献   

9.
以侧柏幼苗为试验材料,采用水培方式,研究不同浓度NaCl(0、100、200、300和400mmol·L~(-1))以及ABA(0、0.5、1、10、100和200μmol·L~(-1)处理对盐胁迫下侧柏幼苗活性氧代谢的影响。结果显示:(1)随着NaCl处理浓度增加,侧柏幼苗叶片过氧化氢(H_2O_2)、丙二醛(MDA)、谷胱甘肽(GSH)和脯氨酸含量,以及抗氧化物酶(SOD、POD和CAT)活性呈上升趋势,而可溶性蛋白含量降低。(2)于300mmol·L~(-1)NaCl胁迫处理48h后进行ABA(1和10μmol·L~(-1))处理,分析发现侧柏幼苗叶片的SOD、POD和CAT活性提高,GSH、脯氨酸和可溶性蛋白含量增加,H_2O_2和MDA的积累减少。(3)NaCl胁迫后,侧柏幼苗叶片活性氧代谢相关基因(Cu/Zn-SOD、CAT、GR、APX、MDAR和GST)的表达水平随ABA浓度增加呈先升后降的趋势,并于10μmol·L~(-1) ABA处理48h时达到峰值。研究表明,适宜浓度ABA通过促进盐胁迫下侧柏幼苗叶片的抗氧化物酶活性,提高渗透调节能力,增加GSH含量,降低H_2O_2和MDA积累,从而有效降低活性氧对侧柏叶片的伤害,保护细胞膜结构的完整,增强其抗盐性。  相似文献   

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赵天宏  刘波  王岩  刘轶鸥  赵超然  杨兴  曹莹 《生态学报》2015,35(8):2695-2702
揭示大豆叶片内源激素对UV-B和臭氧胁迫的代谢机制和响应方式,为从分子水平研究植物内源激素对UV-B(Ultraviolet-B)和O3(Ozone)胁迫的适应机制奠定基础。以大豆(Glycine max.)为试验材料,利用开顶式气室研究UV-B(0.32W/m2)和O3((110±10)nmol/mol)复合胁迫对大豆叶片内源激素含量及活性氧代谢系统的影响。结果表明:在大豆整个生育期内,与对照相比,UV-B胁迫使大豆叶片ABA(Abscisic acid)含量、ZR(Zeatin riboside)含量和IAA(Indoleacetic acid)含量显著降低,IAA/ABA、ZR/ABA、(IAA+ZR)/ABA比值升高,O·-2(Superoxide anion free radical,O·-2)产生速率和MDA(Malonaldehyde)含量升高,SOD(Superoxide dismutase)、CAT(Catalase)和POD(Peroxidase)活性显著降低;高浓度O3胁迫下,大豆叶片ABA和IAA含量显著下降、ZR含量显著增加,IAA/ABA、ZR/ABA、(IAA+ZR)/ABA值显著升高,O·-2产生速率和MDA含量增加,SOD、CAT和POD活性显著降低;UV-B和O3复合胁迫下,大豆叶片ABA含量、ZR含量和IAA含量降低,ZR/ABA、(IAA+ZR)/ABA值下降,而IAA/ABA值升高,O·-2产生速率和MDA含量显著增加,SOD、CAT和POD活性显著降低。UV-B辐射增强和O3浓度升高单一及复合作用使大豆叶片内源激素间平衡改变,进而影响大豆叶片的代谢水平。持续胁迫下,植株抗氧化能力下降,对大豆表现为伤害效应。UV-B和O3复合胁迫比单独胁迫时的影响有所加深,但是小于两者单独作用时影响的简单累加。  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

18.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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