scholarly journals Arabidopsis late blight: infection of a nonhost plant byAlbugo laibachiienables full colonization byPhytophthora infestans

2016 ◽  
Vol 19 (1) ◽  
pp. e12628 ◽  
Author(s):  
Khaoula Belhaj ◽  
Liliana M. Cano ◽  
David C. Prince ◽  
Ariane Kemen ◽  
Kentaro Yoshida ◽  
...  
Keyword(s):  
2015 ◽  
Author(s):  
Khaoula Belhaj ◽  
Liliana M. Cano ◽  
David C. Prince ◽  
Ariane Kemen ◽  
Kentaro Yoshida ◽  
...  

AbstractThe oomycete pathogen Phytophthora infestans causes potato late blight, and as a potato and tomato specialist pathogen, is seemingly poorly adapted to infect plants outside the Solanaceae. Here, we report the unexpected finding that P. infestans can infect Arabidopsis thaliana when another oomycete pathogen, Albugo laibachii, has colonized the host plant. The behaviour and speed of P. infestans infection in Arabidopsis pre-infected with A. laibachii resemble P. infestans infection of susceptible potato plants. Transcriptional profiling of P. infestans genes during infection revealed a significant overlap in the sets of secreted-protein genes that are induced in P. infestans upon colonisation of potato and susceptible Arabidopsis, suggesting major similarities in P. infestans gene expression dynamics on the two plant species. Furthermore, we found haustoria of A. laibachii and P. infestans within the same Arabidopsis cells. This Arabidopsis - A. laibachii - P. infestans tripartite interaction opens up various possibilities to dissect the molecular mechanisms of P. infestans infection and the processes occurring in co-infected Arabidopsis cells.


Author(s):  
A.I. Ivanov ◽  
Zh.A. Ivanova ◽  
O.I. Yakusheva ◽  
P.A. Filippov

Целью комплексного исследования, выполненного в Меньковском филиале АФИ в 20122017 годах была оценка вредоносности возбудителя фитофтороза в зависимости от почвенноагрохимических и погодноклиматических условий. Методической основой исследования служил длительный полевой опыт агрофизический стационар в системе полевого и овощекормового севооборотов, в которых картофель возделывали по обороту пласта многолетних трав после озимой ржи и после ячменя. Объектами исследования служили: картофель раннеспелого сорта Ломоносовский среднеустойчивого к возбудителю фитофтороза по клубням и слабоустойчивого по ботве дерновоподзолистая почва средней, хорошей и высокой степени окультуренности и системы удобрения культуры. Супесчаная почва опыта характеризовалась рНКСl 5,26,3, содержанием гумуса 2,13,7, подвижных соединений P2О5 195676 мг/кг и К2О 97298 мг/кг. На хорошо окультуренной и высокоокультуренной почвах их поддерживали применением под картофель 35 и 70 т/га органических удобрений соответственно. Факторы исследования: степень окультуренности почвы (варианты: средняя, хорошая и высокая) и уровень применения минеральных удобрений в расчете на заданный КПД (коэффициент полезного действия фотосинтетически активной радиации) (варианты: КПД ФАР, 13 без удобрений КПД ФАР, 24 N80P20K100 КПД ФАР, 35 N120P30K150). В ходе комплексного исследования установлены параметры поражения возбудителем фитофтороза и уровень потерь урожая картофеля в зависимости от агроклиматических и почвенноагрохимических условий. Агрономическая эффективность изученных вариантов системы удобрения на культуре картофеля высокая. Уровень прибавок урожайности клубней и окупаемость 1 кг д.в. удобрений достигли 3358 и 8,311,6 з.ед. (зерновых единиц) на минеральной, 2545 и 3,98,0 з.ед. на органической и 3379 и 3,86,7 з.ед. на органоминеральной системе удобрения. В неэпифитотийных условиях (2 из 3 лет наблюдений) на фоне низких и умеренных показателей поражения общие потери урожая составляют 5, а окультуривание почвы и применение органических и минеральных удобрений снижают их на 3080. На эпифитотийном фоне, повторяющемся 1 раз в 3 года, пораженность ботвы и клубней картофеля возрастает в 4,3 и 6,1, интенсивность поражения в 2,8 и 3 и развитие в 12 и 17,5 раза соответственно. В эпифитотийные годы потери урожая возрастают в 5,2 раза (до 26), а минеральная система удобрения сокращает их только на среднеокультуренной почве. На этом фоне повышение степени окультуренности почвы и доз органических удобрений до высокого уровня неэффективно.Late blight is one of the most harmful potato diseases in the NorthWest of Russia. Today, its negative effects are aggravated by weather and climate changes. The goal of a comprehensive study carried out in the Menkovsky branch of the Agrophysical Institute in 2012 2017 was an assessment of the harmfulness of the late blight pathogen depending on soilagrochemical, weather and climate conditions. The methodical basis of the research was a prolonged field agrophysical stationary experiment in the system of field and vegetablefeed crop rotations, where potato was cultivated after winter rye and after barley, which, in turn, were grown after perennial grasses. The objects of the study were potato Lomonosovsky, sodpodzolic soil with different degree of cultivation and fertilizer systems for the culture. Potato Lomonosovsky is early ripening variety, its tubers are medium resistant to the late blight agent, and its tops are weakly resistant to it. The sodpodzolic soil had average, good and high cultivation degree. Sandy loam soil in the experiment had the value of pHKCl of 5.2 6.3, the humus content of 2.1 3.7, the content of mobile P2O5 and K2O compounds of 195 676, 97 298 mg/kg, respectively. In well and highly cultivated soils, these parameters were maintained by the application of 35 and 70 t/ha of organic fertilizers for potato, respectively. The experimental factors were the degree of soil cultivation (average, good and high) and the level of mineral fertilizer application for a given efficiency of photosynthetically active radiation (PAR efficiency of 1 3, without fertilizers PAR efficiency of 2 4, N80P20K100 PAR efficiency of 3 5, N120P30K150). In the course of the comprehensive study, the parameters of potato damage by late blight and the level of crop losses were established depending on the agroclimatic soilagrochemical conditions. Agronomic efficiency of the studied variants of the fertilizer system for potato was high. The level of tuber yield increase and payback of 1 kg of fertilizers active substances reached 33 58 and 8.3 11.6 cereal units (CU) for the mineral system, 25 45 and 3.9 8.0 CU for the organic one, and 33 79 and 3.8 6.7 CU for the organic and mineral fertilizer system. Under nonepiphytotic conditions (2 of 3 years of the observation), against the background of low and moderate damage rates, the total yield loss was 5, and the soil improvement and organic and mineral fertilizer application reduced them by 30 80. Against an epiphytotic background, repeated 1 time in 3 years, the damage of tops and potato tubers increases by a factor of 4.3 and 6.1, the intensity of the damage grew 2.8 and 3 times, and the development increases by a factor of 12 and 17.5 times, respectively. In the epiphytotic years, yield losses increased 5.2 times (up to 26), and the mineral fertilizer system reduced them only in medium cultured soil. Against this background, increasing the soil cultivation degree and organic fertilizer doses to a high level is ineffective.


2018 ◽  
Vol 34 (6) ◽  
pp. 4-11
Author(s):  
V.K. Chizhik ◽  
◽  
E.A. Sokolova ◽  
V.V. Martynov ◽  
M.A. Kuznetsova ◽  
...  

2013 ◽  
Vol 103 (6) ◽  
pp. 538-544 ◽  
Author(s):  
Glenna M. Malcolm ◽  
Gretchen A. Kuldau ◽  
Beth K. Gugino ◽  
María del Mar Jiménez-Gasco

Much of the current knowledge on population biology and ecology of soilborne fungal pathogens has been derived from research based on populations recovered from plants displaying disease symptoms or soil associated with symptomatic plants. Many soilborne fungal pathogens are known to cause disease on a large number of crop plants, including a variety of important agronomical, horticultural, ornamental, and forest plants species. For instance, the fungus Verticillium dahliae causes disease on >400 host plants. From a phytopathological perspective, plants on which disease symptoms have not been yet observed are considered to be nonhosts for V. dahliae. This term may be misleading because it does not provide information regarding the nature of the plant–fungus association; that is, a nonhost plant may harbor the fungus as an endophyte. Yet, there are numerous instances in the literature where V. dahliae has been isolated from asymptomatic plants; thus, these plants should be considered hosts. In this article, we synthesize scattered research that indicates that V. dahliae, aside from being a successful and significant vascular plant pathogen, may have a cryptic biology on numerous asymptomatic plants as an endophyte. Thus, we suggest here that these endophytic associations among V. dahliae and asymptomatic plants are not unusual relationships in nature. We propose to embrace the broader ecology of many fungi by differentiating between “symptomatic hosts” as those plants in which the infection and colonization by a fungus results in disease, and “asymptomatic hosts” as those plants that harbor the fungus endophytically and are different than true nonhosts that should be used for plant species that do not interact with the given fungus. In fact, if we broaden our definition of “host plant” to include asymptomatic plants that harbor the fungus as an endophyte, it is likely that the host ranges for some soilborne fungal pathogens are much larger than previously envisioned. By ignoring the potential for soilborne fungal pathogens to display endophytic relationships, we leave gaps in our knowledge about the population biology and ecology, persistence, and spread of these fungi in agroecosystems.


2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nam Phuong Kieu ◽  
Marit Lenman ◽  
Eu Sheng Wang ◽  
Bent Larsen Petersen ◽  
Erik Andreasson

AbstractThe use of pathogen-resistant cultivars is expected to increase yield and decrease fungicide use in agriculture. However, in potato breeding, increased resistance obtained via resistance genes (R-genes) is hampered because R-gene(s) are often specific for a pathogen race and can be quickly overcome by the evolution of the pathogen. In parallel, susceptibility genes (S-genes) are important for pathogenesis, and loss of S-gene function confers increased resistance in several plants, such as rice, wheat, citrus and tomatoes. In this article, we present the mutation and screening of seven putative S-genes in potatoes, including two DMR6 potato homologues. Using a CRISPR/Cas9 system, which conferred co-expression of two guide RNAs, tetra-allelic deletion mutants were generated and resistance against late blight was assayed in the plants. Functional knockouts of StDND1, StCHL1, and DMG400000582 (StDMR6-1) generated potatoes with increased resistance against late blight. Plants mutated in StDND1 showed pleiotropic effects, whereas StDMR6-1 and StCHL1 mutated plants did not exhibit any growth phenotype, making them good candidates for further agricultural studies. Additionally, we showed that DMG401026923 (here denoted StDMR6-2) knockout mutants did not demonstrate any increased late blight resistance, but exhibited a growth phenotype, indicating that StDMR6-1 and StDMR6-2 have different functions. To the best of our knowledge, this is the first report on the mutation and screening of putative S-genes in potatoes, including two DMR6 potato homologues.


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