共查询到20条相似文献，搜索用时 15 毫秒
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Laura Masini Laura J. Grenville‐Briggs Erik Andreasson Lars Rberg sa Lankinen 《Ecology and evolution》2019,9(8):4557-4567
Studies of infection by Phytophthora infestans—the causal agent of potato late blight—in wild species can provide novel insights into plant defense responses, and indicate how wild plants might be influenced by recurrent epidemics in agricultural fields. In the present study, our aim was to investigate if different clones of Solanum dulcamara (a relative of potato) collected in the wild differ in resistance and tolerance to infection by a common European isolate of P. infestans. We performed infection experiments with six S. dulcamara genotypes (clones) both in the laboratory and in the field and measured the degree of infection and plant performance traits. In the laboratory, the six evaluated genotypes varied from resistant to susceptible, as measured by degree of infection 20 days post infection. Two of the four genotypes susceptible to infection showed a quadratic (concave downward) relationship between the degree of infection and shoot length, with maximum shoot length at intermediate values of infection. This result suggests overcompensation, that is, an increase in growth in infected individuals. The number of leaves decreased with increasing degree of infection, but at different rates in the four susceptible genotypes, indicating genetic variation for tolerance. In the field, the inoculated genotypes did not show any disease symptoms, but plant biomass at the end of the growing season was higher for inoculated plants than for controls, in‐line with the overcompensation detected in the laboratory. We conclude that in S. dulcamara there are indications of genetic variation for both resistance and tolerance to P. infestans infection. Moreover, some genotypes displayed overcompensation. Learning about plant tolerance and overcompensation to infection by pathogens can help broaden our understanding of plant defense in natural populations and help develop more sustainable plant protection strategies for economically important crop diseases. 相似文献
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Ronny Vlz Ju‐Young Park Soonok Kim Sook‐Young Park William Harris Hyunjung Chung Yong‐Hwan Lee 《The Plant journal : for cell and molecular biology》2020,103(1):412-429
The fungal genus Cochliobolus describes necrotrophic pathogens that give rise to significant losses on rice, wheat, and maize. Revealing plant mechanisms of non‐host resistance (NHR) against Cochliobolus will help to uncover strategies that can be exploited in engineered cereals. Therefore, we developed a heterogeneous pathosystem and studied the ability of Cochliobolus to infect dicotyledons. We report here that C. miyabeanus and C. heterostrophus infect Arabidopsis accessions and produce functional conidia, thereby demonstrating the ability to accept Brassica spp. as host plants. Some ecotypes exhibited a high susceptibility, whereas others hindered the necrotrophic disease progression of the Cochliobolus strains. Natural variation in NHR among the tested Arabidopsis accessions can advance the identification of genetic loci that prime the plant’s defence repertoire. We found that applied phytotoxin‐containing conidial fluid extracts of C. miyabeanus caused necrotic lesions on rice leaves but provoked only minor irritations on Arabidopsis. This result implies that C. miyabeanus phytotoxins are insufficiently adapted to promote dicot colonization, which corresponds to a retarded infection progression. Previous studies on rice demonstrated that ethylene (ET) promotes C. miyabeanus infection, whereas salicylic acid (SA) and jasmonic acid (JA) exert a minor function. However, in Arabidopsis, we revealed that the genetic disruption of the ET and JA signalling pathways compromises basal resistance against Cochliobolus, whereas SA biosynthesis mutants showed a reduced susceptibility. Our results refer to the synergistic action of ET/JA and indicate distinct defence systems between Arabidopsis and rice to confine Cochliobolus propagation. Moreover, this heterogeneous pathosystem may help to reveal mechanisms of NHR and associated defensive genes against Cochliobolus infection. 相似文献
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Ning Jiang Jun Cui Xinxin Hou Guanglei Yang Yu Xiao Lu Han Jun Meng Yushi Luan 《The Plant journal : for cell and molecular biology》2020,103(4):1561-1574
Long non‐coding RNAs (lncRNAs) are involved in the resistance of plants to infection by pathogens via interactions with microRNAs (miRNAs). Long non‐coding RNAs are cleaved by miRNAs to produce phased small interfering RNAs (phasiRNAs), which, as competing endogenous RNAs (ceRNAs), function as decoys for mature miRNAs, thus inhibiting their expression, and contain pre‐miRNA sequences to produce mature miRNAs. However, whether lncRNAs and miRNAs mediate other molecular mechanisms during plant resistance to pathogens is unknown. In this study, as a positive regulator, Sl‐lncRNA15492 from tomato (Solanum lycopersicum Zaofen No. 2) plants affected tomato resistance to Phytophthora infestans. Gain‐ and loss‐of‐function experiments and RNA ligase‐mediated 5′‐amplification of cDNA ends (RLM‐5′ RACE) also revealed that Sl‐miR482a was negatively involved in tomato resistance by targeting Sl‐NBS‐LRR genes and that silencing of Sl‐NBS‐LRR1 decreased tomato resistance. Sl‐lncRNA15492 inhibited the expression of mature Sl‐miR482a, whose precursor was located within the antisense sequence of Sl‐lncRNA15492. Further degradome analysis and additional RLM‐5′ RACE experiments verified that mature Sl‐miR482a could also cleave Sl‐lncRNA15492. These results provide a mechanism by which lncRNAs might inhibit precursor miRNA expression through antisense strands of lncRNAs, and demonstrate that Sl‐lncRNA15492 and Sl‐miR482a mutually inhibit the maintenance of Sl‐NBS‐LRR1 homeostasis during tomato resistance to P. infestans. 相似文献
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E‐Jiao Wu Yan‐Ping Wang Lurwanu Yahuza Meng‐Han He Dan‐Li Sun Yan‐Mei Huang Yu‐Chan Liu Li‐Na Yang Wen Zhu Jiasui Zhan 《Evolutionary Applications》2020,13(4):768-780
Temperature plays a multidimensional role in host–pathogen interactions. As an important element of climate change, elevated world temperature resulting from global warming presents new challenges to sustainable disease management. Knowledge of pathogen adaptation to global warming is needed to predict future disease epidemiology and formulate mitigating strategies. In this study, 21 Phytophthora infestans isolates originating from seven thermal environments were acclimated for 200 days under stepwise increase or decrease of experimental temperatures and evolutionary responses of the isolates to the thermal changes were evaluated. We found temperature acclimation significantly increased the fitness and genetic adaptation of P. infestans isolates at both low and high temperatures. Low‐temperature acclimation enforced the countergradient adaptation of the pathogen to its past selection and enhanced the positive association between the pathogen's intrinsic growth rate and aggressiveness. At high temperatures, we found that pathogen growth collapsed near the maximum temperature for growth, suggesting a thermal niche boundary may exist in the evolutionary adaptation of P. infestans. These results indicate that pathogens can quickly adapt to temperature shifts in global warming. If this is associated with environmental conditions favoring pathogen spread, it will threaten future food security and human health and require the establishment of mitigating actions. 相似文献
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Marc Ghislain Arinaitwe Abel Byarugaba Eric Magembe Anne Njoroge Cristina Rivera María Lupe Romn Jos Carlos Tovar Soledad Gamboa Gregory A. Forbes Jan F. Kreuze Alex Barekye Andrew Kiggundu 《Plant biotechnology journal》2019,17(6):1119-1129
Considered responsible for one million deaths in Ireland and widespread famine in the European continent during the 1840s, late blight, caused by Phytophthora infestans, remains the most devastating disease of potato (Solanum tuberosum L.) with about 15%–30% annual yield loss in sub‐Saharan Africa, affecting mainly smallholder farmers. We show here that the transfer of three resistance (R) genes from wild relatives [RB, Rpi‐blb2 from Solanum bulbocastanum and Rpi‐vnt1.1 from S. venturii] into potato provided complete resistance in the field over several seasons. We observed that the stacking of the three R genes produced a high frequency of transgenic events with resistance to late blight. In the field, 13 resistant transgenic events with the 3R‐gene stack from the potato varieties ‘Desiree’ and ‘Victoria’ grew normally without showing pathogen damage and without any fungicide spray, whereas their non‐transgenic equivalent varieties were rapidly killed. Characteristics of the local pathogen population suggest that the resistance to late blight may be long‐lasting because it has low diversity, and essentially consists of the single lineage, 2_A1, which expresses the cognate avirulence effector genes. Yields of two transgenic events from ‘Desiree’ and ‘Victoria’ grown without fungicide to reflect small‐scale farm holders were estimated to be 29 and 45 t/ha respectively. This represents a three to four‐fold increase over the national average. Thus, these late blight resistant potato varieties, which are the farmers’ preferred varieties, could be rapidly adopted and bring significant income to smallholder farmers in sub‐Saharan Africa. 相似文献
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Oomycetes are one type of the most highly destructive of the diseases that cause damage to some important crop plants, such as potato late blight, cucumber downy mildew, and grape downy mildew. As main approach of the ongoing search for new botanical fungicide from plant, the secondary metabolites of D. aspersa were investigated. Through efficient bioassay‐guided isolation, two new ( 1 and 2 ) and 12 known compounds ( 3 – 14 ) were isolated, and their structures were determined via extensive NMR, HR‐ESI‐MS, and IR. They were isolated from this genus for the first time except for compounds 11 and 12 . The biological properties of 1 – 14 were evaluated against Pseudoperonospora cubensis and Phytophthora infestans. Compounds 1 – 8 showed potent antifungal activity in vitro. Additionally, compound 3 has preferable control effect on cucumber downy mildew, showing dual effect of protection and treatment in vivo. 相似文献
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Pallem Chowdappa Nirmal B. J. Kumar Shivanna Madhura Mohan S. P. Kumar Kevin L. Myers William E. Fry Julie N. Squires David E. L. Cooke 《Journal of Phytopathology》2013,161(1):49-58
Prior to 2007, late blight was not reported as a serious threat to tomato cultivation in India although the disease has been known on potato since 1953. During the July–December cropping season of 2009 and 2010, severe late blight epidemics were observed in Karnataka state of India, causing crop losses up to 100%. Nineteen Phytophthora isolates, recovered from late blight affected tomato tissues from different localities in Karnataka state between 2009 and 2010, were identified as Phytophthora infestans based on morphology, a similarity search of ITS sequences at GenBank and species‐specific PCR using PINF/ITS5 primer pair. The isolates were further assessed for metalaxyl sensitivity, mating type, mitochondrial DNA (mtDNA) haplotype, DNA fingerprinting patterns based on simple sequence repeats (SSR) and RFLPs using the RG57 probe and aggressiveness on tomato. All isolates were metalaxyl resistant, A2 mating type, mtDNA haplotype Ia and had identical SSR and RG57 fingerprints and highly aggressive on tomato. The phenotypic and genotypic characters of isolates examined in this study were found to be similar to that of 13_A2 genotype of P. infestans population reported in Europe. Thus, appearance of new population similar to 13_A2 genotype was responsible for severe late blight epidemics on tomato in South‐West India. 相似文献
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Françoise Bafort Olivier Parisi Jean‐Paul Perraudin Mohammed Haïssam Jijakli 《Journal of Phytopathology》2017,165(1):22-34
Controlling pests in pre‐ and postharvest crops using natural and low‐impact products is a major challenge. The lactoperoxidase system is an enzymatic system that exists in all external secretions in mammals and is part of the non‐immune system. We tested its efficacy in in vitro microplates on Phytophthora infestans, Penicillium digitatum, Penicillium italicum, Penicillium expansum and Botrytis cinerea to determine the most suitable concentrations for use. Then, we verified its efficacy in planta under controlled conditions. Solutions prepared with 5.4 mm iodide and 1.2 mm thiocyanate and diluted threefold inhibited pathogen growth in vitro by 63–100%. Twofold‐diluted solutions protected potato plants against P. infestans by 60–74% under controlled conditions. Undiluted solution inhibited orange's and apple's postharvest pathogens in curative application with efficacy levels ranging between 84 and 95% in orange and between 63 and 74% in apple. 1.5‐fold concentrated solutions inhibited postharvest pathogens of apple in curative application with efficacy levels ranging between 84 and 92%. Our results also show that the oxidative stress response of fruit following wounding could interfere with ion efficiency. Our tests demonstrate for the first time that this biochemical method is as efficient as a conventional synthetic chemical method under controlled conditions. 相似文献
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Priyank Hanuman Mhatre Divya K. Lekshmanan Venkatasalam E. Palanisamy Aarti Bairwa Sanjeev Sharma 《Journal of Phytopathology》2021,169(1):52-61
Late blight of potato is considered to be the most devastating problem causing severe yield losses in potato worldwide. Among the different management strategies, the use of resistant cultivars is the most viable option, but the non‐availability of enough quantity of quality seed materials of resistant cultivars forces the farmers to grow susceptible cultivars with proper fungicide scheduling. Therefore, in the present study, chemical control using fungicide has been attempted with newer molecules in the susceptible cultivar along with a resistant cultivar as a positive control. All the tested fungicides were found safe, and no phytotoxicity was observed with any chemical at the applied rate. In resistant cultivar, no late blight was appeared in both the years, whereas maximum AUDPC was observed in the untreated control (276.3) and minimum (41.7) in mancozeb‐cymoxanil + mancozeb based scheduling which was found on par with chlorothalonil‐famoxadone + cymoxanil (51.3) and chlorothalonil‐ametoctradin + dimethomorph (53.5) based scheduling. Among the treatments, resistant cultivar, Kufri Girdhari followed by chlorothalonil‐ametoctradin + dimethomorph and mancozeb‐cymoxanil + mancozeb based fungicidal scheduling were proven as the best treatments for both the crop seasons resulting in the highest yield parameters. The disease severity showed a strong negative correlation with the tuber yield of potatoes in both the years. Based on overall observations including BC ratio, it can be concluded that, wherever seed material of resistant cultivar is available farmers should grow the same or else with susceptible cultivars the fungicidal scheduling based on mancozeb‐cymoxanil + mancozeb or chlorothalonil‐ametoctradin + dimethomorph can be followed to obtain the maximum returns with effective management of late blight at the southern hills of India. 相似文献
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Fabio Rezzonico Philippe C. Nicot Johannes Fahrentrapp 《Journal of Phytopathology》2018,166(2):123-128
Reliable reference genes are critical for relative quantification using quantitative real‐time PCR (qPCR). Ten tomato genes (Solanum lycopersicum) and their respective primer sets, which have been used over the last 6 years as references in expression studies, were evaluated for their performance using leaf tissue samples grown under semi‐controlled conditions and infected with grey mould (Botrytis cinerea) or late blight (Phytophthora infestans). The target genes coding for U6 snRNA‐associated Sm‐like protein LSm7, calcineurin B‐like protein and V‐type proton ATPase were the most stable expressed of all the genes tested in three experimental repetitions. Evaluation of candidate reference genes with geNorm and NormFinder softwares yielded the lowest mean values for their respective primer sets LSM7, SlCBL1 and SlATPase, suggesting stable expression. However, SlATPase primer set revealed a comparably high intra‐group variation and was thus not considered further. In follow‐up experiments with P. infestans, the geNorm and NormFinder values of primer sets LSM7 and SlCBL1 were even lower, indicating the stability of their expression also under these conditions. Primer efficiency differed by ‐18 to +5 percentage points from values presented in the literature. Our findings show that a reference primer set which delivers the best results in one system may be outperformed by another under different experimental conditions, thus recommending a reassessment of both expression stability and qPCR efficiency whenever the biological or technical experimental set‐up is changed. On the basis of our results, we recommend the use of LSM7 and SlCBL1 as reference primer sets for gene expression studies on plant tissue derived from open or semi‐controlled conditions. 相似文献
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Jorge Alejandro Rojas William W. Kirk Esther Gachango David S. Douches Linda E. Hanson 《Journal of Phytopathology》2014,162(1):33-42
Migrations or introduction of new genotypes of Phytophthora infestans to a specific region imposes a different perspective for potato production. During 2009–2010, a late blight epidemic affected the Northeastern United States, which quickly spread through several states. The epidemic was characterized by the appearance of a new genotype of P. infestans designated US‐22, which was isolated from tomato and potato. Potato tubers are an essential component of late blight epidemics where the pathogen cannot overwinter on Solanaceous plants. Six potato cultivars were inoculated with 12 isolates of P. infestans (five different genotypes), including isolates of the genotype US‐22. Tuber blight development was characterized in terms of tissue darkening expressed as area under the disease progress curve values and lenticel infection. The responses indicated that US‐8 was more aggressive than US‐22, but US‐22 isolates obtained from potato were more aggressive on potato than those acquired from tomato. Tuber periderm responses to infection were limited, yet US‐8 isolates infected the periderm more often than US‐22 isolates. There were significant differences among the cultivars tested but cv. Jacqueline Lee was the most resistant overall. Although isolates of P. infestans genotype US‐22 were less aggressive in comparison with US‐8 isolates, US‐22 isolates still infected potato tubers and were as aggressive us US‐8 isolates on some cultivars. Management of late blight caused by isolates of US‐22 through host resistance may be feasible but imposes a different set of criteria for consideration from those that US‐8 imposed. 相似文献
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Chun Hong Yang Paul J. De Barro Fang Hao Wan 《Entomologia Experimentalis et Applicata》2013,147(3):282-292
The differences in the ability of the invading whitefly, Bemisia tabaci (Gennadius) (commonly known as biotype B and hereafter as B) and Trialeurodes vaporariorum (Westwood) (both Hemiptera: Aleyrodidae) to utilize salivary phenol‐oxidizing enzymes – polyphenol oxidase (PPO) and peroxidase (POD) to detoxify plant defensive phenolic compounds were explored. Polyphenol oxidase and POD were found in the saliva of both B and T. vaporariorum. For tomato colonies, the PPO and POD activities in the watery saliva of B were 2.27‐ and 1.34‐fold higher than those of T. vaporariorum. The PPO activities against specific phenolic compounds commonly found in plants were compared. The activities of those from B were significantly greater than those from T. vaporariorum. We also measured PPO activity in both species after they had fed on plants that were undamaged or had been previously damaged with either a plant pathogen [Phytophthora infestans (Mont.) de Bary (Peronosporales)] infection, mechanical damage, B infestation, or exogenous salicylic acid. For B, PPO activities in watery saliva increased 229, 184, 152, and 139% in response to the four treatments, whereas those of T. vaporariorum only increased 133, 119, 113, and 103%, respectively. Biotype B infestation significantly increased the total phenolic content of tomato leaves. Meanwhile, feeding on tomato infestation with B had no significant effect on the survival rate of B, but decreased the survival rate of T. vaporariorum significantly. These results suggest that B has stronger ability utilizing PPO to detoxify high concentrations of phenolics than T. vaporariorum, and this contributes to a significant advantage for B to hold high fitness on plants with induced resistance. Possible roles of salivary PPO in the competition between B and T. vaporariorum are discussed. 相似文献
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Many Gram‐negative plant pathogenic bacteria express effector proteins of the XopQ/HopQ1 family which are translocated into plant cells via the type III secretion system during infection. In Nicotiana benthamiana, recognition of XopQ/HopQ1 proteins induces an effector‐triggered immunity (ETI) reaction which is not associated with strong cell death but renders plants immune against Pseudomonas syringae and Xanthomonas campestris pv. vesicatoria strains. Additionally, XopQ suppresses cell death in N. benthamiana when transiently co‐expressed with cell death inducers. Here, we show that representative XopQ/HopQ1 proteins are recognized similarly, likely by a single resistance protein of the TIR‐NB‐LRR class. Extensive analysis of XopQ derivatives indicates the recognition of structural features. We performed Agrobacterium‐mediated protein expression experiments in wild‐type and EDS1‐deficient (eds1) N. benthamiana leaves, not recognizing XopQ/HopQ1. XopQ recognition limits multiplication of Agrobacterium and attenuates levels of transiently expressed proteins. Remarkably, XopQ fails to suppress cell death reactions induced by different effectors in eds1 plants. We conclude that XopQ‐mediated cell death suppression in N. benthamiana is due to the attenuation of Agrobacterium‐mediated protein expression rather than the cause of the genuine XopQ virulence activity. Thus, our study expands our understanding of XopQ recognition and function, and also challenges the commonly used co‐expression assays for elucidation of in planta effector activities, at least under conditions of ETI induction. 相似文献
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E‐Jiao Wu Ce Yang Peter H. Thrall Jeremy J. Burdon Li‐Ping Jin Li‐Ping Shang Jiasui Zhan 《Molecular ecology》2016,25(16):4047-4058
Temperature is one of the most important environmental parameters with crucial impacts on nearly all biological processes. Due to anthropogenic activity, average air temperatures are expected to increase by a few degrees in coming decades, accompanied by an increased occurrence of extreme temperature events. Such global trends are likely to have various major impacts on human society through their influence on natural ecosystems, food production and biotic interactions, including diseases. In this study, we used a combination of statistical genetics, experimental evolution and common garden experiments to investigate the evolutionary potential for thermal adaptation in the potato late blight pathogen, Phytophthora infestans, and infer its likely response to changing temperatures. We found a trade‐off associated with thermal adaptation to heterogeneous environments in P. infestans, with the degree of the trade‐off peaking approximately at the pathogen's optimum growth temperature. A genetic trade‐off in thermal adaptation was also evidenced by the negative association between a strain's growth rate and its thermal range for growth, and warm climates selecting for a low pathogen growth rate. We also found a mirror effect of phenotypic plasticity and genetic adaptation on growth rate. At below the optimum, phenotypic plasticity enhances pathogen's growth rate but nature selects for slower growing genotypes when temperature increases. At above the optimum, phenotypic plasticity reduces pathogen's growth rate but natural selection favours for faster growing genotypes when temperature increases further. We conclude from these findings that the growth rate of P. infestans will only be marginally affected by global warming. 相似文献