scholarly journals Does salinity affect lifestyle switching in the plant pathogen Fusarium solani?

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Louise Eydoux ◽  
Emily C. Farrer
Keyword(s):  
Root Growth ◽  
Fusarium Solani ◽  
Model Organism ◽  
Common Reed ◽  
Soil Salinization ◽  
Native Plant ◽  
Crop Species ◽  
Elevated Salinity ◽  
Weak Evidence ◽  
A Minor

Symbiotic microbes that live within plant hosts can exhibit a range in function from mutualistic to pathogenic, but the reason for this lifestyle switching remains largely unknown. Here we tested whether environmental stress, specifically salinity, is a factor that can trigger lifestyle switching in a fungus mainly known as a pathogen, Fusarium solani. F. solani was isolated from roots of Phragmites australis (common reed) in saline coastal marshes of Louisiana, USA, and we used Oryza sativa (rice) as a model organism from wetland environments to test the symbiont lifestyle. We plated rice seeds on control plates or plates with F. solani at three levels of salinity (0, 8 and 16 p.p.t.), then assessed germination and seedling growth after 20 days. Salinity strongly reduced percentage germination, slowed the timing of germination and reduced growth of rice. F. solani slowed germination, and it also caused a minor increase in root growth at medium salinity and a minor decrease in root growth at high salinity. Overall, despite being a common pathogen in other crop species (peas, beans, potatoes and many types of cucurbits), we found little evidence that F. solani has a strong pathogenic lifestyle in rice and we found weak evidence that pathogenicity may increase slightly with elevated salinity. These results have implications for both crops and native plant health in the future as soil salinization increases worldwide.

scholarly journals Characterising the effect of crop species and fertilisation treatment on root fungal communities

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Liina Soonvald ◽  
Kaire Loit ◽  
Eve Runno-Paurson ◽  
Alar Astover ◽  
Leho Tedersoo
Keyword(s):  
Fungal Community ◽  
Farmyard Manure ◽  
Illumina Miseq ◽  
Diversity Indices ◽  
Community Diversity ◽  
Its2 Region ◽  
Minor Effect ◽  
Crop Species ◽  
A Minor ◽  
Fertilisation Treatment

Abstract Information about the root mycobiome may improve the overall quality of the plants and contribute to a valuable strategy to enhance sustainable agriculture. Therefore, we assessed differences in fungal community diversity and composition in the roots of potato, wheat and barley grown under mineral nitrogen fertilisation at five rates, with and without farmyard manure amendment. The same factorial combination of treatments has been used since 1989. Species richness and diversity, as well as community composition, of different fungal guilds were characterised using Illumina MiSeq sequencing of the ITS2 region. Crop species was the main factor determining overall fungal richness and diversity, with wheat showing the highest, and potato the lowest, richness and diversity. Pathogen diversity indices were highest in wheat plots amended with farmyard manure, whereas the lowest values were observed for potato roots. Fertilisation treatments and the interaction between crop species and fertilisation had the strongest impact on arbuscular mycorrhiza and saprotroph diversity. Crop species also determined the composition of the overall fungal community and that of fungal guilds, whereas fertilisation treatment had only a minor effect. This study highlights crop species as the main driver in shaping root fungal diversity and composition under the same environmental conditions.

scholarly journals Response of Cucumber (Cucumis sativus L.) and Squash (Cucurbita pepo L. var. melopepo) Roots to Chilling Stress during Early Stages of Seedling Development

1994 ◽  
Vol 119 (5) ◽  
pp. 964-970 ◽  
Author(s):  
Eleazar Reyes ◽  
Paul H. Jennings
Keyword(s):  
Root Growth ◽  
Cucumis Sativus ◽  
Cucurbita Pepo ◽  
Chilling Stress ◽  
Dry Weight ◽  
Root Tip ◽  
Crop Species ◽  
Cucumis Sativus L ◽  
Chilling Temperatures ◽  
Cucumber Roots

Roots of `Golden Girl' squash (Cucurbita pepo var. melopepo) and `Encore' cucumber (Cucumis sativus L.), 4- and 3-days-old, respectively, were exposed to 2, 6, 10, and 15C for 24, 48, 96, 144, and 192 hours to compare the sensitivity to chilling temperatures and the subsequent recovery at more favorable temperatures. Seedlings were more sensitive to chilling at 2 and 6C when measured by their ability to resume growth when returned to 26C. Root growth decreased after 48 hours of chilling. Seedlings stressed at 10 and 15C were able to continue root growth at these temperatures and when returned to 26C. However, seedlings at 10C exhibited root-tip browning in both crop species, suggesting disfunction in metabolic pathways that were repressed in seedlings growing at 2C where those symptoms were not present. Effects on root dry weight occurred in the first 24 hours at all temperatures studied. After 96 hours of treatment, seedlings grown at 2 and 6C were irreversibly damaged, as evidenced by their inability to resume growth when returned to 26C. Leakage of electrolytes from squash and cucumber roots increased after 48 hours at 2C. Potassium, Na+, and PO4-2 were lost in greater amounts than Mg+2, Cl-, and SO4-2. No difference in ionic leakage occurred at 10 and 15C, and Ca+2 leakage was not detected at any chilling stress temperature.

scholarly journals Crown and Root Infection of Lisianthus Caused by Fusarium solani in South Africa

Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 573-573 ◽  
Author(s):  
M. Truter ◽  
F. C. Wehner
Keyword(s):  
South Africa ◽  
Fusarium Solani ◽  
Fusarium Species ◽  
Crown Rot ◽  
Hypodermic Needle ◽  
State University ◽  
Root Infection ◽  
Gauteng Province ◽  
Eustoma Grandiflorum ◽  
A Minor

Cultivation of lisianthus (Eustoma grandiflorum (Raf.) Shinn.) is a minor industry in South Africa, with only a few growers producing the crop commercially. Commercial production at a location in Gauteng Province is hampered by rotting of the crowns and roots of plants that result in mortality of as much as 22% of the plants. At advanced stages of infection, the crowns of affected plants characteristically are covered with masses of fusoid, curved hyalophragmospores. Crowns and roots of symptomatic plants that were submitted by the grower in January 2003 were surface disinfested by immersing for 2 min in a 3% solution of sodium hypochlorite, and segments excised from the plant tissue were plated on potato dextrose agar supplemented with 50 mg l-1 of rifampicin. Fusarium solani (Mart.) Appel & Wollenw. (1), was consistently and exclusively isolated from the segments. Teleomorph Nectria haematococca Berk. & Broome, commonly developed in culture after incubation for 4 to 6 weeks, although no sexual structures were observed on infected plants. A spore suspension containing 104 micro- and macroconidia ml-1 was prepared for each of two single-conidial isolates of F. solani. Using a 0.8-mm-diameter hypodermic needle, 100 μl of each suspension was injected subepi-dermally into the crown of each of three 1-month-old disease-free lisian-thus plantlets (cv. Texas Blue Bell) growing in 500-ml plastic pots filled with sterilized vermiculite. In addition, each suspension was incorporated at 2% (vol/vol) into three pots with sterile vermiculite, and a plantlet was planted in each pot. Control plantlets were treated similarly, but with sterile distilled water. All inoculated plantlets developed crown rot and wilted within 2 weeks while maintained at 28°C in a greenhouse, regardless of mode of inoculation, and F. solani was readily reisolated from their crowns and roots. Control plantlets remained symptomless and did not yield F. solani. Crown and root infection of lisianthus by F. solani has been described (2,3), but to our knowledge, this is the first report of the disease in South Africa. References: (1) P. E. Nelson et al. Fusarium species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park. 1983. (2) J. J. Taubenhaus and W. N. Ezekiel. Phytopathology 24:19, 1934. (3) S. Wolcan et al. Plant Dis. 85:443, 2001.

scholarly journals Timing, location and crop species influence the magnitude of amelioration of aluminum toxicity by magnesium

2009 ◽  
Vol 33 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Ivo Ribeiro Silva ◽  
Tarcísio Fernando Cortes Corrêa ◽  
Roberto Ferreira Novais ◽  
T. Jot Smyth ◽  
Thomas Rufty ◽  
...  
Keyword(s):  
Root Growth ◽  
Protective Effect ◽  
Root System ◽  
Aluminum Toxicity ◽  
Protective Action ◽  
Al Toxicity ◽  
Al Tolerance ◽  
Crop Species ◽  
Soybean Cultivars ◽  
Split Root System

The protective effect of cations, especially Ca and Mg, against aluminum (Al) rhizotoxicity has been extensively investigated in the last decades. The mechanisms by which the process occurs are however only beginning to be elucidated. Six experiments were carried out here to characterize the protective effect of Mg application in relation to timing, location and crop specificity: Experiment 1 - Protective effect of Mg compared to Ca; Experiment 2 - Protective effect of Mg on distinct root classes of 15 soybean genotypes; Experiment 3 - Effect of timing of Mg supply on the response of soybean cvs. to Al; Experiment 4 - Investigating whether the Mg protective effect is apoplastic or simplastic using a split-root system; Experiment 5 - Protective effect of Mg supplied in solution or foliar spraying, and Experiment 6 - Protective effect of Mg on Al rhizotoxicity in other crops. It was found that the addition of 50 mmol L-1 Mg to solutions containing toxic Al increased Al tolerance in 15 soybean cultivars. This caused soybean cultivars known as Al-sensitive to behave as if they were tolerant. The protective action of Mg seems to require constant Mg supply in the external medium. Supplying Mg up to 6 h after root exposition to Al was sufficient to maintain normal soybean root growth, but root growth was not recovered by Mg addition 12 h after Al treatments. Mg application to half of the root system not exposed to Al was not sufficient to prevent Al toxicity on the other half exposed to Al without Mg in rooting medium, indicating the existence of an external protection mechanism of Mg. Foliar spraying with Mg also failed to decrease Al toxicity, indicating a possible apoplastic role of Mg. The protective effect of Mg appeared to be soybean-specific since Mg supply did not substantially improve root elongation in sorghum, wheat, corn, cotton, rice, or snap bean when grown in the presence of toxic Al concentrations.

scholarly journals Native Plant Recovery following Three Years of Common Reed (Phragmites australis) Control

2018 ◽  
Vol 11 (4) ◽  
pp. 175-180 ◽  
Author(s):  
Christopher L. Zimmerman ◽  
Rebecca R. Shirer ◽  
Jeffrey D. Corbin
Keyword(s):  
Phragmites Australis ◽  
Native Species ◽  
Plant Cover ◽  
Management Strategies ◽  
Species Abundance ◽  
Common Reed ◽  
Exotic Plant ◽  
Native Plant ◽  
Native Community ◽  
Native Plant Community

AbstractProjects that aim to control invasive species often assume that a reduction of the target species will increase native species abundance. However, reports of the responses of native species following exotic species control are relatively rare. We assessed the recovery of the native community in five tidal wetland locations in which we attempted to eradicate the invasive common reed [Phragmites australis (Cav.) Trin. ex Steud.]. We tested whether 3 yr of treatment were able to eradicate Phragmites and promote recovery of the native plant community. After 3 yr of treatment, Phragmites density declined sharply in all treated stands, though it was not eradicated in any of them. Native plant cover increased significantly in treated areas, and community composition, particularly in smaller stands, converged toward that of uninvaded habitat. Thus, even within the relatively short timescale of the treatments and monitoring, significant progress was made toward achieving the goals of controlling Phragmites infestations and promoting native biodiversity. There was a trend toward greater promise for success in smaller stands than larger stands, as has been observed in other studies. A greater emphasis on monitoring whole-community responses to exotic plant control, across a range of conditions, would enhance our ability to plan and design successful management strategies.

Comparison of Fixed-Wall and Pressurized-Wall Minirhizotrons for Fine Root Growth Measurements in Eight Crop Species

2005 ◽  
Vol 97 (5) ◽  
pp. 1367-1373 ◽  
Author(s):  
Stephen D. Merrill ◽  
Donald L. Tanaka ◽  
Jonathan D. Hanson
Keyword(s):  
Root Growth ◽  
Fine Root ◽  
Crop Species ◽  
Fine Root Growth

scholarly journals Ectopic expression of the sesame MYB transcription factor SiMYB305 promotes root growth and modulates ABA-mediated tolerance to drought and salt stresses in Arabidopsis

AoB Plants ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Komivi Dossa ◽  
Marie A Mmadi ◽  
Rong Zhou ◽  
Aili Liu ◽  
Yuanxiao Yang ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Root Growth ◽  
Stress Tolerance ◽  
Cell Damage ◽  
Abiotic Stress Tolerance ◽  
Stomatal Closure ◽  
Ectopic Expression ◽  
Myb Transcription Factor ◽  
Marker Genes ◽  
Crop Species

Abstract An increasing number of candidate genes related to abiotic stress tolerance are being discovered and proposed to improve the existing cultivars of the high oil-bearing crop sesame (Sesamum indicum L.). However, the in planta functional validation of these genes is remarkably lacking. In this study, we cloned a novel sesame R2-R3 MYB gene SiMYB75 which is strongly induced by drought, sodium chloride (NaCl), abscisic acid (ABA) and mannitol. SiMYB75 is expressed in various sesame tissues, especially in root and its protein is predicted to be located in the nucleus. Ectopic over-expression of SiMYB75 in Arabidopsis notably promoted root growth and improved plant tolerance to drought, NaCl and mannitol treatments. Furthermore, SiMYB75 over-expressing lines accumulated higher content of ABA than wild-type plants under stresses and also increased sensitivity to ABA. Physiological analyses revealed that SiMYB75 confers abiotic stress tolerance by promoting stomatal closure to reduce water loss; inducing a strong reactive oxygen species scavenging activity to alleviate cell damage and apoptosis; and also, up-regulating the expression levels of various stress-marker genes in the ABA-dependent pathways. Our data suggested that SiMYB75 positively modulates drought, salt and osmotic stresses responses through ABA-mediated pathways. Thus, SiMYB75 could be a promising candidate gene for the improvement of abiotic stress tolerance in crop species including sesame.

Growth vigour of some crop species and cultivars when fall-seeded as winter cover in the Atlantic region of Canada

1992 ◽  
Vol 72 (2) ◽  
pp. 421-429 ◽  
Author(s):  
Linnell M. Edwards ◽  
John M. Sadler
Keyword(s):  
Root Growth ◽  
Cover Crops ◽  
Exploratory Study ◽  
Field Experiments ◽  
Seed Mass ◽  
Cultivar Differences ◽  
Winter Rye ◽  
Crop Species ◽  
Seeding Date ◽  
Winter Rapeseed

Field experiments were conducted in Charlottetown, Prince Edward Island, Canada to determine the crop species or cultivars best suited for use as fall-seeded cover crops to follow late potatoes. Performance was primarily assessed as accumulated fall growth as dry mass/plant from seeding to freeze-up. An exploratory study was done to compare gramineous crops comprising cultivars of winter rye (Secale cereale L.), barley (Hordeum vulgare L.), oats (Avena sativa), and ryegrass (Lolium multiflorum L.). Rye cultivars generally outperformed barley by 38%, oats by 80%, and ryegrass by 130%. Field experiments were conducted over 2 or 3 yr to compare selected cultivars of winter rapeseed (Brassica napus Brinks, Jet Neuf, and BK 27-79) or winter rye (cv. Kodiak, Horton, Aroostok, and Tetrapetkus). In interspecific comparisons, rye was twice as productive as rapeseed in root biomass. In intraspecific comparisons, Tetrapetkus and Kodiak rye generally outperformed the other rye cultivars, while rapeseed showed no cultivar differences. All comparisons showed significant linear decline in cover performance from the first to the third seeding date from 78 to 97% in shoot or root growth. In the exploratory study, seed mass and tillering accounted for up to 95% of the variation in shoot or root growth; and in the rye and rapeseed comparisons, seed mass accounted for up to 82% of this variation.Key words: Cover crops, winter rye, spring cereals, ryegrass, winter rapeseed, seeding date

Managing Remnant and Reemerging Common Reed (Phragmites australis) Infestations to Improve Treatment Efficacy and Mitigate Damage to Native Plants

2014 ◽  
Vol 7 (3) ◽  
pp. 445-453 ◽  
Author(s):  
Daniel B. Breen ◽  
Stephen D. Bailey ◽  
Helen A. Violi
Keyword(s):  
Phragmites Australis ◽  
Large Scale ◽  
Effective Means ◽  
Common Reed ◽  
Native Plant ◽  
Litter Removal ◽  
Mechanical Cutting ◽  
New Treatments ◽  
Assateague Island ◽  
Herbicide Use

AbstractFollowing large-scale herbicide spraying and burning on Assateague Island, a barrier bar island located in Maryland and Virginia, the invasive common reed (Phragmites australis) was largely reduced from vast monocultures to less dense patches interspersed within maritime shrublands. To improve the control of these remnant/reemerging infestations and limit further nontarget damage, we tested three new treatments: mechanical cutting followed by dripping imazapyr onto stems, cutting followed 2 wk later by the foliar spraying of regrowth, and simple cutting with and without the removal of Phragmites litter. All herbicide treatments and cutting paired with litter removal significantly reduced Phragmites coverage (P ≤ 0.01) when compared with untreated controls. Native plant coverage was significantly greater after the cut-stem treatment than after traditional foliar spraying (P ≤ 0.01) because of the former's reduced herbicide use and more direct contact limited to Phragmites stems; native coverage was also greater after litter removal than when litter remained (P ≤ 0.001). Cutting followed by stem applications of herbicide is an effective means of treating scattered common reed stands in sensitive habitats, and litter removal after cutting can provide native vegetation with an advantage at recolonization.

Sign in / Sign up

Export Citation Format

Share Document