The Role of Flowers in the Disease Cycle of Colletotrichum fioriniae and Other Cranberry Fruit Rot Fungi

2020 ◽  
Vol 110 (7) ◽  
pp. 1270-1279
Author(s):  
Timothy J. Waller ◽  
J. Gager ◽  
Christine Constantelos ◽  
Peter V. Oudemans
Keyword(s):  
Plant Pathogens ◽  
Growing Season ◽  
Growth Patterns ◽  
Fruit Rot ◽  
Plant Canopy ◽  
Appressorium Formation ◽  
Disease Cycle ◽  
Colletotrichum Spp ◽  
Latent Pathogens

Floral extracts (FEs) can influence the infectivity and epidemiology of fruit infecting Colletotrichum species. In this study, Colletotrichum fioriniae responded to cranberry FEs with an increased rate and magnitude of secondary conidiation and appressorium formation. Four other cranberry fruit rotting species also showed an increased rate of germination in the presence of FEs. However, increased appressorium formation was observed only in the latent pathogens Coleophoma cylindrospora, Colletotrichum fructivorum, and Colletotrichum fioriniae. Two other fruit rotting species, Phyllosticta vaccinii and Allantophomopsis lycopodina, did not form appressoria while secondary conidiation was only seen with the Colletotrichum spp. When conidia of Colletotrichum fioriniae were inoculated in the presence of FE, the incidence of disease was greater on cranberry fruit. Conidia of this species also formed appressoria at lower than expected temperatures in the presence of FE. Dissection of the flowers revealed that the corolla (with stamens and stigma) was the most stimulatory part of the inflorescence. These observations suggest an important and ephemeral role of flowers in the epidemiology of fruit rot. Stimulatory floral signals were readily detected using a conidial germination bioassay and rainwater samples collected from the plant canopy throughout the growing season confirmed that bioactivity was highest during the bloom period, and declined as the fruit developed. The data presented show that floral signals can alter the growth patterns of a larger than previously observed range of fungi and the mobility of floral signals within the canopy implicates these phenology-specific cues in modifying the disease cycles of numerous plant pathogens.

Adaptation and response to mycotoxin presence in pathogen-pathogen interactions within the Fusarium genus

2016 ◽  
Vol 9 (4) ◽  
pp. 565-575 ◽  
Author(s):  
A. Dawidziuk ◽  
G. Koczyk ◽  
D. Popiel
Keyword(s):  
Fusarium Graminearum ◽  
Plant Pathogens ◽  
Fusarium Verticillioides ◽  
Warning Signal ◽  
Resistance Mechanisms ◽  
Growth Patterns ◽  
Fungal Plant Pathogens ◽  
Low Concentrations ◽  
Dose Dependent

The ability of fungal plant pathogens to exude bioactive compounds is an important element of competition in a changing environment. The filamentous fungi usually retain a number of adaptations related not only to the production of toxic compounds by themselves but also to the mitigation of exogenous influences by toxins present in the environment. We examined a distinct effect of toxins on morphology, growth patterns and gene expression after stimulation in mycotoxin-producing and nonproducing isolates representing four evolutionarily divergent species (and chemotypes) within the Fusarium genus (Fusarium graminearum, Fusarium oxysporum, Fusarium proliferatum and Fusarium verticillioides). The aim of our work was to investigate the influence of mycotoxins present in the environment on fungal isolates belonging to evolutionarily divergent complexes within Fusarium genus. The results point to retention of resistance mechanisms in non-producer isolates (F. oxysporum) and specific dose-dependent differences in response to other mycotoxins. In particular, the growth of Fusarium graminearum (confirmed zearalenone and trichothecene producer) was shown to be significantly inhibited by fumonisin B1 and deoxynivalenol. Conversely, spread of Fusarium verticillioides was accelerated by low concentrations (0.5 mg/l) of nivalenol and zearalenone and deoxynivalenol addition resulted in upregulation of the fumonisin poliketyde synthase (FUM1). The basics of competition between divergent fusaria can be described by ‘rock-paper-scissors’ theory, but some of the effects can be explained by other interactions, e.g. autotoxicity of deoxynivalenol and the potential role of low doses of trichothecenes and zearalenone acting as a ‘warning signal’ for competing species.

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

scholarly journals Comparison of the Radial Growth Response of Picea crassifolia to Climate Change in Different Regions of the Central and Eastern Qilian Mountains

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1015
Author(s):  
Xuan Wu ◽  
Liang Jiao ◽  
Dashi Du ◽  
Changliang Qi ◽  
Ruhong Xue
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Central Region ◽  
Radial Growth ◽  
Growing Season ◽  
Qilian Mountains ◽  
Growth Patterns ◽  
Total Precipitation ◽  
Picea Crassifolia ◽  
The Qilian Mountains

It is important to explore the responses of radial tree growth in different regions to understand growth patterns and to enhance forest management and protection with climate change. We constructed tree ring width chronologies of Picea crassifolia from different regions of the Qilian Mountains of northwest China. We used Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth–climate relationship, while spatial correlation is the result of further testing the first two terms in space. The conclusions were as follows: (1) Radial growth had different trends, showing an increasing followed by a decreasing trend in the central region, a continuously increasing trend in the eastern region, and a gradually decreasing trend in the isolated mountain. (2) Radial tree growth in the central region and isolated mountains was constrained by drought stress, and tree growth in the central region was significantly negatively correlated with growing season temperature. Isolated mountains showed a significant negative correlation with mean minimum of growing season and a significant positive correlation with total precipitation. (3) Temporal dynamic responses of radial growth in the central region to the temperatures and SPEI (the standardized precipitation evapotranspiration index) in the growing season were unstable, the isolated mountains to total precipitation was unstable, and that to SPEI was stable. The results of this study suggest that scientific management and maintenance plans of the forest ecosystem should be developed according to the response and growth patterns of the Qinghai spruce to climate change in different regions of the Qilian Mountains.

Kaolin impacts on hormonal balance, polyphenolic composition and oenological parameters in red grapevine berries during ripening

2021 ◽  
pp. 1-15
Author(s):  
Sara Bernardo ◽  
Lia-Tânia Dinis ◽  
Nelson Machado ◽  
Ana Barros ◽  
Marta Pitarch-Bielsa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Growing Season ◽  
Growing Seasons ◽  
Polyphenolic Composition ◽  
Berry Ripening ◽  
Hormonal Balance ◽  
Summer Stress ◽  
Fruit Damage ◽  
Stress Signals

BACKGROUND: Kaolin particle-film application is a well-known strategy to avoid fruit damage. However, its putative role in balancing berry ripening under a changing climate remains poorly explored. OBJECTIVE: We assessed kaolin treatment effect on several ripening berry components, hormonal balance and oenological parameters of the field-grown Touriga-Franca (TF) and Touriga–Nacional (TN) grapevine varieties at veraison (EL35) and ripening (EL38) during two growing seasons (2017 and 2018). RESULTS: Under the adverse summer conditions (two heatwave events) of 2017, kaolin application increased 211.2 %and 51.4 %the salicylic acid (SA) and abscisic acid (ABA) levels in TF berries at EL38, while no significant differences were observed in TN. Conversely, TF, and TN kaolin treated berries showed lower SA and ABA accumulation in 2018, respectively. Tartaric acid content increased about 17.2 %, and 24.2 %in TF and TN treated berries at stage EL35 in the 2017 growing season. Though kaolin treatment had no consistent effect on anthocyanins accumulation, flavonoids, ortho-diphenols and tannins increased in kaolin treated grapevines in 2017. CONCLUSIONS: This study highlights the key role of climate in triggering ripening related processes and fruit quality potential. Nevertheless, kaolin treated grapevines displayed an improved response to oxidative stress signals by increasing secondary metabolites accumulation in warm vintages. Kaolin application promoted different varietal responses, with a possible ripening delaying effect in TF, reinforcing its efficiency in alleviating severe summer stress impacts.

scholarly journals High-Quality Genome Resource of the Pathogen of Diaporthe (Phomopsis) phragmitis Causing Kiwifruit Soft Rot

2020 ◽  
Author(s):  
Pu Liu ◽  
Wang Xiaojie ◽  
Dong Hongjie ◽  
Jianbin Lan ◽  
Kuan Liang ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Management Strategies ◽  
Soft Rot ◽  
Fruit Rot ◽  
Economic Plant ◽  
High Quality ◽  
Total Size ◽  
Genome Wide ◽  
Solid Foundation ◽  
High Quality Genome

Diaporthe spp. are critical plant pathogens that cause wood cankers, wilt, dieback, and fruit rot in a wide variety of economic plant hosts and are regarded as one of the most acute threats faced by kiwifruit industry worldwide. Diaporthe phragmitis strain NJD1 is a highly pathogenic isolate of soft rot of kiwifruit. Here, we present a high-quality genome-wide sequence of D. phragmitis NJD1 that was assembled into 28 contigs containing a total size of 58.33 Mb and N50 length of 3.55 Mb. These results lay a solid foundation for understanding host–pathogen interaction and improving disease management strategies.

scholarly journals Demand and Defective Growth Patterns: The Role of The Tradable and Non-Tradable Sectors in an Open Economy

2014 ◽  
Vol 104 (5) ◽  
pp. 272-277 ◽  
Author(s):  
Sandile Hlatshwayo ◽  
Michael Spence
Keyword(s):  
Open Economy ◽  
Aggregate Demand ◽  
Value Added ◽  
Growth Patterns ◽  
Structural Elements ◽  
Total Income ◽  
Us Economy ◽  
The Us ◽  
Tradable Sector

This paper examines the underlying structural elements of US growth patterns, pre- and post-crisis. Prior to the recession, the US economy exhibited a defective growth pattern driven by outsized domestic demand. As domestic aggregate demand retreats to more sustainable levels relative to total income, the tradable side of the economy is a catalyst for restoring strong growth. A structural rebalancing is already underway; although it is only a third of the economy, the tradable sector generated more than half of gross gains in value-added since the start of the recovery. However, distributional issues loom on the horizon.

scholarly journals Identification and Characterization of Diaporthe ambigua, D. australafricana, D. novem, and D. rudis Causing a Postharvest Fruit Rot in Kiwifruit

Plant Disease ◽  
2017 ◽  
Vol 101 (8) ◽  
pp. 1402-1410 ◽  
Author(s):  
Gonzalo A. Díaz ◽  
Bernardo A. Latorre ◽  
Mauricio Lolas ◽  
Enrique Ferrada ◽  
Paulina Naranjo ◽  
...  
Keyword(s):  
San Francisco ◽  
Plant Pathogens ◽  
Elongation Factor ◽  
Its Region ◽  
Fruit Rot ◽  
Lesion Length ◽  
Translation Elongation ◽  
Wide Range ◽  
Postharvest Rot ◽  
Diaporthe Ambigua

Diaporthe spp. are important plant pathogens causing wood cankers, blight, dieback, and fruit rot in a wide range of hosts. During surveys conducted during the 2013 and 2014 seasons, a postharvest rot in Hayward kiwifruit (Actinidia deliciosa) was observed in Chile. In order to identify the species of Diaporthe associated with this fruit rot, symptomatic fruit were collected from seven kiwifruit packinghouses located between San Francisco de Mostazal and Curicó (central Chile). Twenty-four isolates of Diaporthe spp. were identified from infected fruit based on morphological and cultural characters and analyses of nucleotides sequences of three loci, including the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2), a partial sequences of the β-tubulin, and translation elongation factor 1-α genes. The Diaporthe spp. identified were Diaporthe ambigua, D. australafricana, D. novem, and D. rudis. Multilocus phylogenetic analysis revealed that Chilean isolates were grouped in separate clades with their correspondent ex-types species. All species of Diaporthe were pathogenic on wounded kiwifruit after 30 days at 0°C under normal and controlled-atmosphere (2% O2 and 5% CO2) storage and they were sensitive to benomyl, pyraclostrobin, and tebuconazole fungicides. D. ambigua isolates were the most virulent based on the lesion length measured in inoculated Hayward and Jintao kiwifruit. These findings confirm D. ambigua, D. australafricana, D. novem, and D. rudis as the causal agents of kiwifruit rot during cold storage in Chile. The specie D. actinidiae, a common of Diaporthe sp. found associated with kiwifruit rot, was not identified in the present study.

scholarly journals The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

2016 ◽  
Vol 68 (2) ◽  
pp. 451-459
Author(s):  
Urszula Jankiewicz ◽  
Maria Swiontek-Brzezinska
Keyword(s):  
Plant Pathogens ◽  
Chitinase Activity ◽  
Maximum Activity ◽  
Synergistic Action ◽  
Chitinolytic Activity ◽  
Fungistatic Activity ◽  
Rhizosphere Bacterium ◽  
Paenibacillus Sp ◽  
Growth Inhibiting

The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose). The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria.

scholarly journals ACCUMULATION BEHAVIOUR OF ALLANTOIN IN THE UNDERGROUND PHYTOMASS OF THE BORAGINACEAE FAMILY AND ITS ROLE IN ADAPTING THE PLANTS TO ADVERSE ENVIRONMENTAL FACTORS

2019 ◽  
Vol 14 (1) ◽  
pp. 126-136
Author(s):  
A. Ya. Tamakhina ◽  
A. A. Akhkubekova ◽  
A. B. Ittiev
Keyword(s):  
Solar Radiation ◽  
Sea Level ◽  
Low Temperatures ◽  
High Performance ◽  
Growing Season ◽  
Stress Factors ◽  
Adaptation To Stress ◽  
Plant Adaptation ◽  
The Family

Aim.The aim of the work described herein was to study the dynamics of allantoin accumulation in the underground phytomass ofEchium vulgareL.,Symphytum caucasicumM. Bieb. andS. asperumLepech. as well as to clarify the role of allantoin in plant adaptation to stress factors.Methods.We studied the roots of plants growing in the foothill (Nalchik, 490–512 m above sea level) and the mountain zones of the Kabardino-Balkarian Republic (Terskol village, 2530 m above sea level; Verkhnyaya Balkaria village, 2680 m above sea level). The roots were collected at the stages of rosetting, flowering, fruiting and at the end of the growing season. Aqueous-alcoholic extracts of shredded roots were analyzed by high-performance liquid chromatography.Results.The highest content of allantoin in the roots ofEchium vulgare,Symphytum caucasicum,S. asperumplants was noted at the end of the growing season, respectively 0.915; 0.342–0.658; 2,842–3,426%. Under conditions of low temperatures and increased solar radiation, the content of allantoin in the roots increases 1.2–1.9 times as compared with the plants of the foothill zone.Conclusion.Allantoin plays an important role in the process of adapting species of the family Boraginaceae to oxidative stress caused by hypothermia and increased solar radiation.

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