部分葡萄品种和砧木抗葡萄根瘤蚜性能鉴定

为了检测我国葡萄品种和砧木对中国生态型葡萄根瘤蚜Daktulosphaira viticola (Fitch) 的抗性,在实验室条件下采用离体根接种法鉴定了10个葡萄砧木、18个葡萄栽培品种,测定了根瘤蚜存活率、发育历期、产卵量、种群龄期结构指数和成虫大小等指标。结果表明： 砧木品种SO4,5BB,1103P,420A,Lot,101-14MG,3309C,140Ru和110R抗根瘤蚜,接种后蚜虫陆续死亡,尤其是SO4,5BB,1103P和420A对根瘤蚜高抗,使根瘤蚜滞育仅发育至1龄。我国当作砧木使用的贝达不抗根瘤蚜,接种后蚜虫存活率始终保持在38.82％～47.5%,日产卵量达9.01;欧美杂交种中的康克、康拜尔和卡它巴对根瘤蚜稍有抗性,根瘤蚜日产卵量在6.00～6.85粒之间,其中康克、康拜尔葡萄上蚜虫的存活率随时间的延长而明显降低,由最初的60％下降至25％～30％; 欧美杂交种中的黑虎香和白香蕉虽然在一定程度上能够限制根瘤蚜的存活和发育进程,但对根瘤蚜的繁殖量没有影响。所有供试欧亚种和欧美杂交种的栽培品种都对根瘤蚜高度敏感,接种后第29 d 蚜虫存活率仍保持在40％～60％,且前后变化较小,日产卵量变化于7～12.35粒之间,总产卵量均在190粒以上。由此可见,我国供试栽培品种均不抗根瘤蚜,在根瘤蚜疫区需要用抗性砧木嫁接苗建园。     

施钾提高蚜害诱导的小麦茉莉酸含量和叶片相关防御酶活性

研究表明,施钾能够提高作物对蚜虫的抗性,但其机理尚不明确。试验采用营养液培养的方法,设置2 mmol/L和0.005mmol/L KCl两个钾浓度,分析不同钾水平培养下的小麦植株在蚜虫为害后,体内茉莉酸(JA)和水杨酸(SA)的含量和脂氧合酶(LOX)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)等防御酶活性的变化。结果表明,低钾胁迫显著降低了小麦体内JA和SA的含量,并且诱导LOX和POD酶活性增强,但是对PPO和PAL酶活性没有显著影响。蚜虫为害48 h后,高钾小麦体内JA含量显著高于低钾植株,而SA含量没有明显变化。高钾显著提高了蚜虫为害后小麦叶片中的LOX、PAL、PPO和POD酶活性,而低钾小麦体内4种酶的活性在整个虫害调查期间均没有显著变化。研究表明,充足供钾能够显著提高小麦受到蚜虫为害后体内茉莉酸含量,激活其体内的JA信号传导途径,从而提高防御酶活性,增强其对蚜虫的抵御能力。     

茉莉酸甲酯对菊花抗蚜性的影响

本研究以杭白菊为试验材料,分析茉莉酸甲酯对菊花抗蚜性的影响。供试幼苗叶面喷施不同浓度(0.01、0.05、0.1、0.5、1 mmol·L^-1)茉莉酸甲酯后接种菊姬长管蚜,测定外源茉莉酸甲酯对蚜虫胁迫下菊花叶片的保护酶、防御酶活性、渗透性物质、次生代谢物和茉莉酸途径关键酶基因表达的影响,探究菊花抗蚜性与茉莉酸信号途径的关系。结果表明: 0.01、0.05、0.1、0.5、1 mmol·L^-1浓度的茉莉酸甲酯均显著提高了杭白菊叶片的保护酶、防御酶活性及次生代谢物含量,降低了丙二醛和可溶性糖含量,外源茉莉酸甲酯处理诱导杭白菊CmAOS和CmCOI1的表达,并使内源茉莉酸含量显著增加,杭白菊的抗蚜性增强。     

外源茉莉酸诱导枸杞对枸杞蚜生长发育和繁殖的影响

为了明确外源茉莉酸对枸杞的诱导抗性及其对害虫的影响,在室内25℃条件下用3种浓度的茉莉酸喷施枸杞苗木,以喷施丙酮+蒸馏水（配比1∶599）作为对照,测定了枸杞蚜在处理后苗木上的生长发育和繁殖情况。结果表明：外源茉莉酸诱导枸杞苗木后,枸杞蚜若虫发育历期延长,成虫寿命缩短、产仔量下降,枸杞蚜体重减轻,其影响程度与茉莉酸浓度有关。0.01 mmol/L茉莉酸诱导枸杞蚜若虫期最长,为4.93 d,比对照延长1.9 d。茉莉酸诱导成虫产仔量显著减少,且浓度越高产仔量越少,0.1 mmol/L浓度下产仔量为25头,比对照少19头。3种浓度的茉莉酸诱导均使枸杞蚜成虫寿命较对照缩短3 d左右。茉莉酸诱导对枸杞蚜体重的影响从3日龄后逐渐显现,5日龄时最显著,处理组与对照组蚜虫体重相差0.128～0.184 mg,对照组蚜虫平均重0.395 mg,0.01 mmol/L处理组蚜虫重量仅0.211 mg。     

外源茉莉酸和茉莉酸甲酯诱导植物抗虫作用及其机理

综述了茉莉酸(jasmonic acid, JA)和茉莉酸甲酯(methyl jasmo nate, MJA)的分子结构和应用其诱导的植物抗虫作用及其机制。植物受外源茉莉酸或茉莉酸甲酯刺激后,一条反应途径是由硬脂酸途径激活防御基因,另一条途径是直接激活防御基因。防御基因激活后导致代谢途径重新配置,并可能诱导植物产生下列4种效应：（1）直接防御,即植物产生对害虫有毒的物质、抗营养和抗消化的酶类,或具驱避性和妨碍行为作用的化合物;（2）间接防御,即产生吸引天敌的挥发物;（3）不防御,即无防御反应;（4）负防御,即产生吸引害虫的挥发物。     

茉莉酸甲酯与水杨酸在诱导黑麦草颖花开放中的拮抗效应

在意大利黑麦草完全没有开颖的情况下,１mmol.L^-1MeJA处理体穗２min,１１h内可使其单穗颖花开放数达２５左右,表现出明显的诱导效应,滞后期约为１６０min;10mmol.L^-1和１mmol.L^-1的ＳＡ对MeJA诱导的开颖效应均有抑制作用,这种抑制作用可被MeJA处理解除。     

钙肥对葡萄根瘤蚜生长发育和繁殖的影响

【目的】为明确葡萄所需的大量元素钙对葡萄根瘤蚜 Daktulosphaira vitifoliae(Fitch）生长发育和繁殖的影响。【方法】在温室中,设置不同 Ca⁽²⁺⁾浓度（0、2 和 4mmol·L(2+)浓度（0、2 和 4mmol·L^(-1)）的钙全营养液于葡萄全生育期浇灌葡萄,评价离体根段对葡萄根瘤蚜的存活率、若蚜、成蚜寿命和繁殖力的影响。【结果】随着钙离子浓度的增加,葡萄根瘤蚜在葡萄根上的 1 龄若蚜历期缩短 0.80 倍以上,成蚜历期增加超过 1.88倍,寿命显著延长超过 1.18 倍,产卵量提高 3.34 倍以上。与 0 mmol·L(-1)）的钙全营养液于葡萄全生育期浇灌葡萄,评价离体根段对葡萄根瘤蚜的存活率、若蚜、成蚜寿命和繁殖力的影响。【结果】随着钙离子浓度的增加,葡萄根瘤蚜在葡萄根上的 1 龄若蚜历期缩短 0.80 倍以上,成蚜历期增加超过 1.88倍,寿命显著延长超过 1.18 倍,产卵量提高 3.34 倍以上。与 0 mmol·L^(-1) Ca(-1) Ca⁽²⁺⁾和 2 mmol·L(2+)和 2 mmol·L^(-1) Ca(-1) Ca⁽²⁺⁾处理相比,葡萄根瘤蚜在 4 mmol·L(2+)处理相比,葡萄根瘤蚜在 4 mmol·L^(-1) Ca(-1) Ca⁽²⁺⁾处理下的葡萄根上,内禀增长率 r_m、周限增长率 λ 和净增殖率 R_0均最高,分别为（0.191 ± 0.003）、（1.210 ± 0.004）和（169.070 ± 11.897)(P < 0.05）,且世代发育历期显著缩短（P <0.05）。特定年龄龄期存活率 S_(xj)、种群特定年龄繁殖力 m_x和种群特定年龄繁殖值 l_xm_x在 4mmol·L(2+)处理下的葡萄根上,内禀增长率 r_m、周限增长率 λ 和净增殖率 R_0均最高,分别为（0.191 ± 0.003）、（1.210 ± 0.004）和（169.070 ± 11.897)(P < 0.05）,且世代发育历期显著缩短（P <0.05）。特定年龄龄期存活率 S_(xj)、种群特定年龄繁殖力 m_x和种群特定年龄繁殖值 l_xm_x在 4mmol·L^(-1)Ca(-1)Ca⁽²⁺⁾处理种群中保持较高水平,随着钙浓度降低,葡萄根瘤蚜的各生命参数明显降低。【结论】钙元素对葡萄根瘤蚜的生长发育和繁殖能力具有促进作用,葡萄根瘤蚜发生葡萄园更应合理使用钙肥。     

外源水杨酸和茉莉酸对荞麦幼苗耐盐生理特性的效应

以盐敏感荞麦品种‘TQ-0808’幼苗为材料,采用100mmol·L^（-1）NaCl并添加不同浓度水杨酸（sA）和茉莉酸（JA）的处理方法,测定荞麦耐盐生理指标,确定外源SA和JA对荞麦耐盐生理特性的效应。结果表明,外源SA和JA均能明显降低盐胁迫下荞麦叶片质膜透性和丙二醛（MDA）含量,外源SA降低的幅度略高于JA,外源SA最适浓度为0．6mmol·L^（-1）外源SA和JA均能明显增加盐胁迫下荞麦叶片超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）活性及叶片净光合速率,外源JA增加的幅度明显大于SA,外源JA最适浓度为40gmol·L^（-1）。外源sA和JA明显改善盐胁迫下荞麦的生理特性,对盐胁迫具有较好的缓解作用,说明通过适当浓度的外源SA和JA处理来提高荞麦耐盐性是可行的。     

在伤信号传导中茉莉酸与水杨酸的关系

近年来,发现茉莉酸和水杨酸都是植物体对外界伤害作出反应,表达抗性基因的信号分子。水杨酸可抑制茉莉酸类的合成及其所诱导的蛋白基因的表达;茉莉酸能阻止病原侵染后所产缮乃钏岬脑黾印＼岳蛩嵝藕抛纪揪逗退钏嵝藕抛纪揪洞嬖谧沤徊妫。牵裕薪岷蛋白和细胞分裂素可能起着信号开关的作用。     

根瘤蚜侵染不同抗性葡萄对根结形成及植株营养消耗的影响

为探讨不同抗性水平的葡萄砧木和品种被葡萄根瘤蚜Daktulosphaira vitifoliae Fitch侵染形成根结的状况及其对植株营养消耗的影响,采用盆栽方式接种根瘤蚜,测定了葡萄根结数量、质量及碳水化合物和脯氨酸含量等指标。结果表明：砧木5BB,1103P,SO4,3309C,101-14Mgt被根瘤蚜侵染后均不形成根结;140Ru,Lot和110R仅形成少量根结而不能形成根瘤;砧木贝达、栽培品种赤霞珠、巨峰和达米娜不仅能够形成根结和根瘤,而且根系腐烂程度严重。越敏感的品种形成的根结数量和体积越大,达米娜、巨峰和赤霞珠根结重占根重比例分别高达40.02％,37.08％和35.36％,百个根结质量分别是140Ru的4.4,3.5和433倍。3个形成根结的砧木的枝条生长量平均减少16.5％,而4个高感品种的生长量平均减少43％。根结质量与根结内的营养积聚呈正相关,其中根结质量与淀粉含量增加量的相关系数达0.94,与可溶性糖含量增加量的相关系数达0.81,与游离脯氨酸含量增加量的相关系数达0.93。     

Stimulation and attenuation of induced resistance by elicitors and inhibitors of chemical induction in tomato (Lycopersicon esculentum) foliage

Elicitors and inhibitors of chemical induction were used to manipulate the activities of several putative defense-related proteins in leaves of the tomato, Lycopersicon esculentum Mill. The four presumptive defenses manipulated were proteinase inhibitors, polyphenol oxidase, peroxidase, and lipoxygenase. The elicitors used were jasmonic acid, methyl jasmonate, ultraviolet light, and feeding by larvae of the noctuid, Helicoverpa zea Boddie; the inhibitors used were salicylic acid and acetylsalicylic acid. These chemical manipulations were combined with short-term growth assays using larvae of the generalist noctuid, Spodoptera exigua Hubner, in order to assess the relative roles of the proteins in induced resistance to S. exigua. When activities of proteinase inhibitors and/or polyphenol oxidase in leaf tissue were high (e.g., in damaged or elicited plants), growth rates of larvae of S. exigua were low; when activities of polyphenol oxidase and proteinase inhibitors were low (e.g., in undamaged or damaged, inhibited plants), growth rates of larvae were high. In contrast, high activities of peroxidase and lipoxygenase were not associated with decreases in suitability of leaf tissue for S. exigua. The association of high levels of proteinase inhibitors and polyphenol oxidase with resistance to S. exigua – irrespective of the presence or absence of damage – strongly implicates these proteins as causal agents in induced resistance to S. exigua.     

Herbivore-induced rice resistance against rice blast mediated by salicylic acid

In agro-ecosystems,plants are important mediators of interactions between their associated herbivorous insects and microbes,and any change in plants induced by one species may lead to cascading effects on interactions with other species.Often,such effects are regulated by phytohormones such as jasmonic acid(JA)and salicylic acid(SA).Here,we investigated the tripartite interactions among rice plants,three insect herbivores(Chilo suppressalis,Cnaphalocrocis medinalis or Nilapai-vata lugens),and the causal agent of rice blast disease,the fungus Magnaporthe oryzae.We found that pre-infestation of rice by C.suppressalis or N.lugens but not by C.medinalis conferred resistance to M.oryzae.For C.suppressalis and N.lugens,insect infestation without fungal inoculation induced the accumulation of both JA and SA in rice leaves.In contrast,infestation by C.medinalis increased JA levels but reduced SA levels.The exogenous application of SA but not of JA conferred resistance against M.oryzae.These results suggest that preinfestation by C suppressalis or N.lugens conferred resistance against M.oryzae by increasing SA accumulation.These findings enhance our understanding of the interactions among rice plant,insects and pathogens,and provide valuable information for developing an ecologically sound strategy for controlling rice blast.     

Jasmonic acid and salicylic acid activate a common defense system in rice

Jasmonic acid (JA) and salicylic acid (SA) play important roles in plant defense systems. JA and SA signaling pathways interact antagonistically in dicotyledonous plants, but, the status of crosstalk between JA and SA signaling is unknown in monocots. Our rice microarray analysis showed that more than half of the genes upregulated by the SA analog BTH are also upregulated by JA, suggesting that a major portion of the SA-upregulated genes are regulated by JA-dependent signaling in rice. A common defense system that is activated by both JA and SA is thus proposed which plays an important role in pathogen defense responses in rice.     

Plastid omega3-fatty acid desaturase-dependent accumulation of a systemic acquired resistance inducing activity in petiole exudates of Arabidopsis thaliana is independent of jasmonic acid

Systemic acquired resistance (SAR) is an inducible defense mechanism that is activated throughout the plant, subsequent to localized inoculation with a pathogen. The establishment of SAR requires translocation of an unknown signal from the pathogen-inoculated leaf to the distal organs, where salicylic acid-dependent defenses are activated. We demonstrate here that petiole exudates (PeXs) collected from Arabidopsis leaves inoculated with an avirulent (Avr) Pseudomonas syringae strain promote resistance when applied to Arabidopsis, tomato ( Lycopersicum esculentum ) and wheat ( Triticum aestivum ). Arabidopsis FATTY ACID DESATURASE7 ( FAD7 ), SUPPRESSOR OF FATTY ACID DESATURASE DEFICIENCY1 ( SFD1 ) and SFD2 genes are required for accumulation of the SAR-inducing activity. In contrast to Avr PeX from wild-type plants, Avr PeXs from fad7 , sfd1 and sfd2 mutants were unable to activate SAR when applied to wild-type plants. However, the SAR-inducing activity was reconstituted by mixing Avr PeXs collected from fad7 and sfd1 with Avr PeX from the SAR-deficient dir1 mutant. Since FAD7 , SFD1 and SFD2 are involved in plastid glycerolipid biosynthesis and SAR is also compromised in the Arabidopsis monogalactosyldiacylglycerol synthase1 mutant we suggest that a plastid glycerolipid-dependent factor is required in Avr PeX along with the DIR1- encoded lipid transfer protein for long-distance signaling in SAR. FAD7 -synthesized lipids provide fatty acids for synthesis of jasmonic acid (JA). However, co-infiltration of JA and methylJA with Avr PeX from fad7 and sfd1 did not reconstitute the SAR-inducing activity. In addition, JA did not co-purify with the SAR-inducing activity confirming that JA is not the mobile signal in SAR.     

Different mechanisms of Trichoderma virens‐mediated resistance in tomato against Fusarium wilt involve the jasmonic and salicylic acid pathways

In the present study, we investigated the role of Trichoderma virens (TriV_JSB100) spores or cell‐free culture filtrate in the regulation of growth and activation of the defence responses of tomato (Solanum lycopersicum) plants against Fusarium oxysporum f. sp. lycopersici by the development of a biocontrol–plant–pathogen interaction system. Two‐week‐old tomato seedlings primed with TriV_JSB100 spores cultured on barley grains (BGS) or with cell‐free culture filtrate (CF) were inoculated with Fusarium pathogen under glasshouse conditions; this resulted in significantly lower disease incidence in tomato Oogata‐Fukuju plants treated with BGS than in those treated with CF. To dissect the pathways associated with this response, jasmonic acid (JA) and salicylic acid (SA) signalling in BGS‐ and CF‐induced resistance was evaluated using JA‐ and SA‐impaired tomato lines. We observed that JA‐deficient mutant def1 plants were susceptible to Fusarium pathogen when they were treated with BGS. However, wild‐type (WT) BGS‐treated tomato plants showed a higher JA level and significantly lower disease incidence. SA‐deficient mutant NahG plants treated with CF were also found to be susceptible to Fusarium pathogen and displayed low SA levels, whereas WT CF‐treated tomato plants exhibited moderately lower disease levels and substantially higher SA levels. Expression of the JA‐responsive defensin gene PDF1 was induced in WT tomato plants treated with BGS, whereas the SA‐inducible pathogenesis‐related protein 1 acidic (PR1a) gene was up‐regulated in WT tomato plants treated with CF. These results suggest that TriV_JSB100 BGS and CF differentially induce JA and SA signalling cascades for the elicitation of Fusarium oxysporum resistance in tomato.     

水杨酸、茉莉酸和乙烯介导的防卫信号途径相互作用的研究进展

乙烯、水杨酸和茉莉酸是植物体内主要的几个防御信号途径,也是研究比较多的几个信号途径。很多试验证明不同的防御信号途径相互间存在相互作用,他们或相互抑制,或相互促进。从这三种信号途径相互间的作用,及作用的联系点进行综述。