外源茉莉酸甲酯诱导大麦对叶斑病抗性的研究

[目的]初步探讨不同浓度外源茉莉酸甲酯（MeJA）诱导大麦抗叶斑病效应差异及其分子机制,为应用MeJA防治大麦叶斑病提供理论依据。[方法]以‘蒙啤麦3号’大麦品种幼苗为材料,设置不接菌（无菌水处理叶片）、接菌（无菌水处理叶片接种麦根平脐蠕孢菌）和接菌+MeJA（0.5、1.0、1.5、2.0、2.5 mmol/L MeJA喷施叶片后接菌）3组处理,于三叶期调查叶斑病发病情况并据此筛选最适MeJA浓度,然后测定不接菌、接菌及接菌++ MeJA（最适浓度）处理不同处理时间叶片的抗氧化酶、抗病相关酶活性、丙二醛、渗透调节物质含量以及相关基因表达水平。[[结果]]：（1）叶面喷施外源MeJA提高了大麦对叶斑病的抗性,1.5 mmol/L MeJA处理叶片的病情指数较对照显著降低19.03%,诱导抗性效果最佳;（2）与单独接菌处理相比,1.5 mmol/L MeJA处理大麦叶片超氧化物歧化酶、过氧化物酶、过氧化氢酶、几丁质酶和β-,1,3-葡聚糖酶活性均显著提高,而其丙二醛、脯氨酸、可溶性糖和可溶性蛋白含量显著降低,同时其受MeJA调控转录因子及编码抗病相关酶的基因表达量显著上调。[结论]外源喷施1.5 mmol/L MeJA通过调节抗病相关酶活性和渗透调节物质含量,以及调控抗病相关酶基因及茉莉酸信号途径关键转录因子基因表达,进而提高大麦植株的叶斑病抗病性。     

茉莉酸甲酯和水杨酸对丹参幼苗中蔗糖代谢和酚酸类物质积累的影响

以丹参幼苗为材料,研究了茉莉酸甲酯(MeJA)和水杨酸(SA)对其地上地下部分蔗糖代谢和根系中酚酸类物质积累的影响.结果显示:(1)外源施用MeJA能够显著增强幼苗叶片和根中酸性蔗糖转化酶活性,促进蔗糖降解,减少根系中蔗糖含量;同时根中丹参素(来源于酪氨酸-衍生物支路)、原儿茶酸(类苯丙烷支路的中间产物)、咖啡酸(来源于类苯丙烷支路)、迷迭香酸(来源于类苯丙烷支路和酪氨酸-衍生物支路)、丹酚酸B(丹参素、咖啡酸、迷迭香酸的衍生物)以及总酚酸含量均显著增加.(2)外施SA可显著降低幼苗叶片和根中酸性蔗糖转化酶活性及叶片中性蔗糖转化酶活性,抑制蔗糖降解,显著增加地上部分蔗糖含量,根中蔗糖含量和对照相比差异不显著;同时根中丹参素含量减少,但原儿茶酸、咖啡酸以及迷迭香酸含量增加,丹酚酸B和总酚酸类物质含量与对照相比差异不显著.因此推测,植物中蔗糖代谢影响丹参素合成的酪氨酸-衍生物支路,而不影响原儿茶酸、咖啡酸及迷迭香酸等合成的类苯丙烷支路.     

Resistance Induction by Salicylic Acid Formulation in Cassava Plant against Fusarium solani

Fusarium root rot caused by the soil-borne fungus Fusarium solani is one of the most important fungal diseases of cassava in Thailand, resulting in high yield losses of more than 80%. This study aimed to investigate if the exogenous application of salicylic acid formulations (Zacha) can induce resistance in cassava against Fusarium root rot and observe the biochemical changes in induced cassava leaf tissues through synchrotron radiation based on Fourier-transform infrared (SR-FTIR) microspectroscopy. We demonstrated that the application of Zacha11 prototype formulations could induce resistance against Fusarium root rot in cassava. The in vitro experimental results showed that Zacha11 prototype formulations inhibited the growth of F. solani at approximately 34.83%. Furthermore, a significant reduction in the disease severity of Fusarium root rot disease at 60 days after challenge inoculation was observed in cassava plants treated with Zacha11 at a concentration of 500 ppm (9.0%). Population densities of F. solani were determined at 7 days after inoculation. Treatment of the Zacha11 at a concentration of 500 ppm resulted in reduced populations compared with the distilled water control and differences among treatment means at each assay date. Moreover, the SR-FTIR spectral changes of Zacha11-treated epidermal tissues of leaves had higher integral areas of lipids, lignins, and pectins (1,770–1,700/cm), amide I (1,700–1,600/cm), amide II (1,600–1,500/cm), hemicellulose, lignin (1,300–1,200/cm), and cellulose (1,155/cm). Therefore, alteration in defensive carbohydrates, lipids, and proteins contributed to generate barriers against Fusarium invasion in cassava roots, leading to lower the root rot disease severity.     

外源钙和茉莉酸甲酯诱导番茄植株抗灰霉病研究

以‘辽园多丽’番茄幼苗为材料,研究了经钙(Ca)、钙螯合剂(EGTA)和茉莉酸甲酯(MeJA)处理后接种番茄灰霉病幼苗叶片的病情指数、活性氧(H2O2、O2.-)含量和过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性的变化。结果显示:(1)Ca、MeJA、MeJA+Ca处理番茄幼苗的灰霉病发病率分别比对照显著降低32.5%、38.0%和54.5%,而MeJA+Ca处理又显著低于Ca、MeJA处理32.6%和15.3%;MeJA+EGTA处理高于MeJA处理30.3%,但低于EGTA处理13.1%;Ca处理低于EGTA处理34.2%。(2)Ca、MeJA及MeJA+Ca处理番茄幼苗叶片中活性氧积累量高于对照,MeJA+Ca处理又高于Ca、MeJA处理;但MeJA+EGTA处理活性氧积累量低于MeJA处理,而高于EGTA处理;Ca处理的活性氧含量高于EGTA处理。(3)Ca、MeJA及MeJA+Ca处理幼苗叶片的SOD、CAT、POD的活性均比对照提高,且以MeJA+Ca处理最高;而MeJA+EGTA处理抗氧化酶活性低于MeJA处理,但高于EGTA处理;Ca处理抗氧化酶活性高于EGTA处理。研究表明,钙在茉莉酸甲酯诱导番茄抗灰霉病过程中具有重要调节作用,这种作用与钙促进茉莉酸甲酯诱导番茄活性氧积累和抗氧化酶活性有关。     

Salicylic acid dependent signaling promotes basal thermotolerance but is not essential for acquired thermotolerance in Arabidopsis thaliana

Salicylic acid (SA) is reported to protect plants from heat shock (HS), but insufficient is known about its role in thermotolerance or how this relates to SA signaling in pathogen resistance. We tested thermotolerance and expression of pathogenesis-related (PR) and HS proteins (HSPs) in Arabidopsis thaliana genotypes with modified SA signaling: plants with the SA hydroxylase NahG transgene, the nonexpresser of PR proteins (npr1) mutant, and the constitutive expressers of PR proteins (cpr1 and cpr5) mutants. At all growth stages from seeds to 3-week-old plants, we found evidence for SA-dependent signaling in basal thermotolerance (i.e. tolerance of HS without prior heat acclimation). Endogenous SA correlated with basal thermotolerance, with the SA-deficient NahG and SA-accumulating cpr5 genotypes having lowest and highest thermotolerance, respectively. SA promoted thermotolerance during the HS itself and subsequent recovery. Recovery from HS apparently involved an NPR1-dependent pathway but thermotolerance during HS did not. SA reduced electrolyte leakage, indicating that it induced membrane thermoprotection. PR-1 and Hsp17.6 were induced by SA or HS, indicating common factors in pathogen and HS responses. SA-induced Hsp17.6 expression had a different dose-response to PR-1 expression. HS-induced Hsp17.6 protein appeared more slowly in NahG. However, SA only partially induced HSPs. Hsp17.6 induction by HS was more substantial than by SA, and we found no SA effect on Hsp101 expression. All genotypes, including NahG and npr1, were capable of expression of HSPs and acquisition of HS tolerance by prior heat acclimation. Although SA promotes basal thermotolerance, it is not essential for acquired thermotolerance.     

水杨酸诱导植物抗性的研究进展

水杨酸是一种重要的内源信号分子,能够激活一系列植物抗性防卫反应.为了研究这种抗性反应,对水杨酸诱导植物抗病性、抗旱性、抗盐性及与乙烯作用的新进展作了概述,并从水杨酸与过氧化氢及其代谢酶类相互作用的角度探讨了水杨酸诱导植物抗性生理的分子机理.     

茉莉酸甲酯诱导烟草幼苗抗炭疽病与PAL活性及细胞壁物质的关系

探讨了茉莉酸甲酯(methyl jasmonate, Me-Ja)诱导烟草幼苗抗炭疽病与苯丙氨酸解氨酶(PAL)活性、木质素和富含羟脯氨酸蛋白(HRGP)含量的关系。 Me-Ja处理烟草幼苗不仅可以提高幼苗抗炭疽病的能力,而且明显提高幼苗的PAL活性、木质素和HRGP含量; 3个不同抗性品种的烟草幼苗的PAL酶活性、木质素和HRGP含量三者与感病程度之间的负相关都达到显著水平,表明PAL、木质素和富含羟脯氨酸蛋白(HRGP)在茉莉酸甲酯诱导抗病中起关键作用。     

Regulation of Salicylic Acid and N-Hydroxy-Pipecolic Acid in Systemic Acquired Resistance

In plants, salicylic acid (SA) is a central immune signal that is involved in both local and systemic acquired resistance (SAR). In addition to SA, several other chemical signals are also involved in SAR and these include N-hydroxy-pipecolic acid (NHP), a newly discovered plant metabolite that plays a crucial role in SAR. Recent discoveries have led to a better understanding of the biosynthesis of SA and NHP and their signaling during plant defense responses. Here, I review the recent progress in role of SA and NHP in SAR. In addition, I discuss how these signals cooperate with other SAR-inducing chemicals to regulate SAR.     

2种植物生长调节剂诱导烟草抗链格孢菌研究

以链格孢菌Alternaria alternata和烟草Nicotiana tabacum品种云烟87为试材,研究不同浓度茉莉酸甲酯(MeJA)和水杨酸(SA)处理下,链格孢菌菌丝生长情况以及成熟期烟叶防御酶活性与多酚含量变化,探讨植物生长调节剂对烟草抗链格孢菌的影响。结果表明,1 mmol·L^–1 MeJA对链格孢菌的抑制效果最好,抑菌率高达59%以上,其次是3.5 mmol·L^–1SA;MeJA和SA对链格孢菌的抑制效果随药剂浓度升高而增强;0.1 mmol·L^–1 MeJA和2.5 mmol·L^–1 SA能诱导烟草叶片SOD、POD、CAT等防御酶活性,并能降低H₂O₂活性氧含量,尤其以MeJA诱导效果较好。2种植物生长调节剂处理并接种链格孢菌能诱导提高烟叶多酚代谢相关酶PPO及PAL活性,但对烟草多酚类物质影响较小;成熟烟叶中含量较高的前3种多酚物质是绿原酸、芸香苷、隐绿原酸。     

茉莉酸甲酯对花生幼苗生长和抗旱性的影响

经过茉莉酸甲酯处理的花生幼苗,在形态、解剖和生理上都发生变化,其中以１２５ｍｇ／Ｌ处理最显著。处理后的植株幼苗矮化,叶小而厚,叶片贮水细胞大、蒸腾减弱、内源脱落酸和脯氨酸含量增多、过氧化物酶活性加大。由于水分的丧失减少,叶片水分的贮存增加,从而提高幼苗的抗旱性。     

Jasmonate- and salicylate-induced defenses in wheat affect host preference and probing behavior but not performance of the grain aphid,Sitobion avenae

Jasmonate and salicylatemediated signaling pathways play significant roles in induced plant defenses, but there is no sufficient evidence for their roles in monocots against aphids. We exogenously applied methyl jasmonate （MeJA） and salicylic acid （SA） on wheat seedlings and examined biochemical responses in wheat and effects on the grain aphid, Sitobion avenae （Fab.）. Application of MeJA significantly increased levels of wheat＇s polyphenol oxidase, peroxidase and proteinase inhibitor 1, 2 and 6 days after treatment. In twochoice tests, adult aphids preferred control wheat leaves to MeJA or SA treated leaves. Electrical penetration graph （EPG） recordings of aphid probing behavior revealed that on MeJAtreated plants, the duration of aphid＇s first probe was significantly shorter and number of probes was significantly higher than those on control plants. Also total duration of probing on MeJAtreated plants was significantly shorter than on control plants. Total duration of salivation period on SAtreated plants was significantly longer, while mean phloem ingestion period was significantly shorter than on control plants. However, no significant difference in total duration of phloem sap ingestion period was observed among treatments. The EPG data suggest that MeJAdependent resistance factors might be due to feeding deterrents in mesophyll, whereas the SAmediated resistance may be phloembased. We did not observe any significant difference of MeJA and SA application on aphid development, daily fecundity, intrinsic growth rate and population growth. The results indicate that both MeJA and SAinduced defenses in wheat deterred S. avenae colonization processes and feeding behavior, but had no significant effects on its performance.     

The effects of herbicides and mycoparasites at different moisture levels on carpogenic germination in Sclerotinia sclerotiorum

Colonization of plant roots by fluorescent pseudomonads has been correlated with disease suppression. One mechanism may involve altered defense responses in the plant upon colonization. Altered defense responses were observed in bean (Phaseolus vulgaris) inoculated with fluorescent pseudomonads. Systemic effects of root inoculation by Pseudomonas putida isolate Corvallis, P. tolaasii (P9A) and P. aureofaciens REW1-I-1 were observed in bean leaves from 14-day-old plants. SDS- polyacrylamide gel electrophoresis demonstrated that levels of certain acid-soluble proteins increased in the leaf extracts of inoculated plants. Plants inoculated with REW1-I-1 produced more of a 57 M_r protein, and plants inoculated with isolates P9A and REW1-I-1 produced more of a 38 M_r protein. Northern hybridization revealed enhanced accumulation of mRNAs, that encode the pathogenesis-related protein PR1a, in leaves of plants inoculated with P. putida and REW1-I-1. Only REW1-I-1, but not P9A or P. putida induced symptoms of an hypersensitive response on tobacco leaves, bean cotyledons, and in bean suspension cultures. Phenolics and phytoalexins accumulated in bean cotyledons exposed to REW1-I-1 for 24 h but little change in levels of these compounds occurred in cotyledons inoculated with P9A and P. putida. Both suspension culture cells and roots treated with REW1-I-1 rapidly evolved more hydrogen peroxide than those exposed to P9A and P. putida. However, roots from 14-day-old plants colonized by P9A, P. putida or REW1-I-1 did not have higher levels of phenolics, phytoalexins or mRNAs for two enzymes involved in phenolic biosynthesis, phenylalanine-ammonia lyase and chalcone synthase. A selective induction of plant defense strategies upon root colonization by certain pseudomonads is apparent.     

水杨酸诱导植物抗病性的新进展

水杨酸是一种重要的能激活一系列植物抗病防卫反应的内源信号分子.首先介绍了水杨酸在植物抗病性中的作用,并从水杨酸与过氧化氢及其代谢酶类相互作用的角度初步探讨了水杨酸诱导植物抗病性的分子机理,最后概述了目前这一领域中需要进一步研究的若干问题.     

茉莉酸甲酯对水稻种子萌发和贮藏物质降解的影响

茉莉酸甲酯 (methyljasmonate ,MeJA)对水稻 (OryzasativaL .)种子萌发及幼苗生长的作用表现出“双重性”效应 ,低浓度促进种子萌发和幼苗生长 ,最适浓度为 5× 10 -7mol/L ,高浓度作用相反。MeJA对水稻萌发胚乳酸性磷酸酶、α_淀粉酶、淀粉和盐溶蛋白降解作用也如此 ,但它抑制谷蛋白降解。实验结果表明 ,MeJA促进和抑制水稻种子萌发都与α_淀粉酶活性有关。讨论了MeJA对种子萌发作用与ABA作用的异同     

荣莉酸甲酯对丹参培养细胞中迷迭香酸生物合成及相关酶活性的影响

茉莉酸甲酯是植物细胞响应外界刺激产生的重要信号分子,与植物次生代谢物的生物合成有关。本研究考察了茉莉酸甲酯（methyl jasmonate,MeJA）对丹参培养细胞中迷迭香酸（rosmarinic acid,RA）生物合成的影响。结果显示,诱导24h后可显著提高丹参愈伤细胞中RA的积累量及其相关酶（PAL、TAT）的活性,在48h时RA积累量和酶活性达到最大。布洛芬（IBu）处理可抑制MeJA对RA积累量和相关酶活性的促进作用,外源施加MeJA可部分解除IBU对RA合成及其相关酶活性的抑制作用。说明MeJA可以显著促进丹参培养细胞中RA的生物合成,IBU抑制了MeJA合成、PAL和TAT活性,从而导致了RA合成受阻。     

水杨酸对小白菜抗铅胁迫的诱导

0.3 mmol/L铅胁迫下小白菜（Brassica rapa var. chinensis）生长受到显著抑制,0.1 mmol/L水杨酸（salicylic acid）诱导处理能显著缓解0.3 mmol/L铅胁迫对小白菜幼苗生长的抑制;并且水杨酸对铅胁迫下小白菜的生长存在“低促高抑”效应,当水杨酸处理浓度达到1.5 mmol/L时,不但不能缓解铅对小白菜的毒害,反而加重毒害,这可能与高浓度水杨酸与铅形成的复合伤害有关。     

Effect of Methyl Jasmonate on the Germination and the Degradation of Storage Reserve in Rice Seed

The effects of methyl jasmonate (MeJA, Nippon Zeon Co., Ltd, Tokyo, Japan) on germination and the degradation of storage reserve in rice （Oryza sativa L.） seeds were studied. There were dual effects of MeJA on seed germination and seedling growth of rice, low concentration of MeJA promoted germination and seedling growth whereas high concentration of MeJA inhibited germination and seedling growth. The optimal concentration of promotion was 5×10-7 mol/L. The acid phosphatase activity, α-amylase activity, degradation of starch and salt-soluble proteins were affected same as germination by MeJA. MeJA inhibited the degradation of glutelins, the higher the concentration, the higher the extent of inhibition above 5×10-7 mol/L.The results showed that either promotion or inhibition of germination by MeJA was very close to the effect on the activity of α-amylase. The mechanisms between abscisic acid and MeJA affection on seed germination and seedling growth were compared.     

茉莉酸甲酯和脱落酸对绿豆下胚轴质膜H+-ATPase水解活性的影响

茉莉酸甲酯(MeJA)促进绿豆下胚轴质膜H+-ATPase水解活性.活体条件下,50μmol·L-1 MeJA处理7 h的酶活性提高30%;离体条件下,10 μmol·L-1 MeJA处理2 h的酶活性最大,即提高30%.壳梭孢素(FC)和MeJA在离体条件下对H+-ATPase活性的促进效应相同,均提高30%左右,无协同效应;活体条件下,FC促进质膜H+-ATPase水解活性可达70%,而MeJA仅为30%.离体条件下,脱落酸(ABA)对H+-ATPase水解活性无明显促进;而活体条件下则有一定的抑制.