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George Karabourniotis Georgios Liakopoulos Dimosthenis Nikolopoulos Panagiota Bresta 《林业研究》2020,31(1):1-12
As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions. 相似文献
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利用安徽省1951~1995年烤烟单产资料,划分出安徽省烤烟单产丰歉年景,并对歉收年景因气象灾害所造成的烤烟损失量进行了估计。结果表明:40多年来安徽省烤烟歉收年景气象灾害损失量共计10.33万t,价值1.35亿元,歉收年景灾损量平均0.94万t,价值1230万元,烤烟灾损率平均37.22%。 相似文献
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Adrien Gallou Hernán Patricio Lucero Mosquera Sylvie Cranenbrouck Juan Pablo Suárez Stéphane Declerck 《Physiological and Molecular Plant Pathology》2011,76(1):20-26
Biological control of soil-borne pathogens by arbuscular mycorrhizal (AM) fungi has been repeatedly demonstrated. However, their role in the control of above-ground hemibiotrophic pathogens is less conclusive. Here, we investigated in vitro the impact of an AM fungus on Phytophthora infestans in potato plants. The leaf infection index was decreased in mycorrhizal potato plants. Real-Time Quantitative PCR revealed the induction of two pathogenesis related genes (PR1 and PR2) in the leaves of mycorrhizal plants shortly after infection with P. infestans. These results suggested a systemic resistance in mycorrhizal plants, related to the priming of the two PR genes in potato. 相似文献
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Mathiyazhagan Kavino Sankarasubramanian Harish Neelakandan Kumar Duraisamy Saravanakumar Ramasamy Samiyappan 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(4):353-362
Pseudomonas fluorescens strains CHA0 and Pf1 were investigated for their biocontrol efficacy against Banana bunchy top virus (BBTV) in banana (Musa spp.) alone and in combination with chitin under glasshouse and field conditions. Bioformulation of P. fluorescens strain CHA0 with chitin was effective in reducing the banana bunchy top disease (BBTD) incidence in banana under glasshouse
and field conditions. In addition to disease control, the bioformulation increased the economic yield significantly compared
to the untreated control. Increased accumulation of oxidative enzymes, peroxidase (PO), polyphenol oxidase (PPO), phenylalanine
ammonia lyase (PAL), pathogenesis-related (PR) proteins, chitinase, β-1,3-glucanase and phenolics were observed in CHA0 bioformulation
amended with chitin-treated plants challenged with BBTV under glasshouse conditions. Indirect ELISA indicated the reduction
in viral antigen concentration in P. fluorescens strain CHA0 with chitin-treated banana plants corresponding to reduced disease ratings. The present study revealed that induction
of defence enzymes by P. fluorescens with chitin amendment reduced the BBTD incidence and increased bunch yield in banana. 相似文献
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IntroductionChemicaldefenseisoneofanumberofwaysthatpIantsaredefendedfrommammalianherbivore.SuchchemicaldofenseinvolvestheelaborationandaccumuIationoforganicsubstanceswhenthepIanttissueiseaten.Thesubstancesmaybebittertasting,poisonous,oftenodour,orhaveantinutritionaIeffects.Thegreatmajorityofdeferentsubstancesaretheproductsofsecondarymetabolism.TheyrepresenttheammuIacationofendproductsfromarelativeIyIengthpathwayofenzyme-cataIyzedstepsinbio-synthesis.TheproductsarethenchannelIedwithinthepl… 相似文献
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灰飞虱胁迫下水稻防卫相关基因的表达 总被引:2,自引:0,他引:2
灰飞虱是我国水稻生产上的一种重要害虫。运用荧光定量PCR方法及特异性引物,对不同时间(12、24、36、48和72 h)灰飞虱胁迫下抗虫和感虫水稻品种中主要防卫途径的相关基因进行转录水平上定量分析。灰飞虱取食后,与水杨酸合成途径相关的基因PAL、NPR1、EDS1和PAD4在抗灰飞虱品种Mudgo中的表达水平均高于在感虫水稻Kittake中。接虫12 h后,PAL基因表达量达到未接虫时的6.914倍;在Mudgo中,PAL基因相对表达量上升更快,在24、48和72 h分别是Kittake中的42.848、70.743和69.193倍。NPR1基因在灰飞虱为害12、36和72 h后,在Mudgo中的表达量分别是Kittake中的4.690、6.231和4.112倍。与茉莉酸合成相关的基因LOX和AOS2,在灰飞虱为害36 h后,在Kittake中的表达水平显著高于Mudgo中。乙烯信号途径中的受体基因EIN2在Kittake中的表达量也高于Mudgo中。结果表明,灰飞虱取食激活了抗虫水稻Mudgo中依赖水杨酸介导的抗性途径,同时诱导感虫水稻Kittake产生了依赖茉莉酸/乙烯途径的防卫反应,PAL和NPR1基因的表达在调节Mudgo抗灰飞虱中具有重要作用。 相似文献
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Jonne Rodenburg Lammert Bastiaans Ad. H. C. M. Schapendonk Peter E. L. van der Putten Aad van Ast Niels J. Dingemanse Bettina I. G. Haussmann 《Euphytica》2008,160(1):75-87
Striga hermonthica (Del.) Benth. is a parasitic weed on tropical cereals causing serious yield losses in Africa. The use of host crop varieties
with improved resistance and tolerance against this parasite is a key component of an integrated control strategy. Breeding
for tolerance is however seriously hampered by the absence of reliable and yet practical selection measures. The observation
that the photosynthetic rate of tolerant genotypes is less sensitive to Striga infection was used as a starting point to search for suitable selection measures. In a greenhouse pot experiment the effect
of Striga infection on the photosynthesis of four sorghum (Sorghum bicolor [L.] Moench) genotypes, differing in Striga tolerance level, was measured at three moments in time (26, 48 and 75 days after sowing). Genotypes were CK60-B, E36-1, Framida
and Tiémarifing. Measurements involved CO2-assimilation (A) and three chlorophyll fluorescence characteristics (electron transport rate through photosystem II [ETR], photochemical [Pq] and non-photochemical quenching [NPq]). Striga infection negatively affected A, ETR and Pq. Based on A and Pq, genotypes with superior levels of tolerance (Tiémarifing) could be discriminated from genotypes with superior level of resistance
(Framida). Both A and Pq showed high heritabilities and consequently clear and predictable differences between genotypes. Using discriminative ability,
heritability and cost effectiveness as main criteria, photochemical quenching (Pq) was concluded to possess the highest potential to serve as indirect selection measure for host plant tolerance to Striga. Screening should preferably be conducted at relatively high Striga infestation levels, between Striga emergence and host plant flowering. 相似文献