scholarly journals Co-Infections by Fusarium circinatum and Phytophthora spp. on Pinus radiata: Complex Phenotypic and Molecular Interactions

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1976
Author(s):  
Francesco Aloi ◽  
Cristina Zamora-Ballesteros ◽  
Jorge Martín-García ◽  
Julio J. Diez ◽  
Santa Olga Cacciola
Keyword(s):  
Pinus Radiata ◽  
Defense Mechanism ◽  
Pyruvate Decarboxylase ◽  
Multiple Infections ◽  
Post Inoculation ◽  
Canker Disease ◽  
Monterey Pine ◽  
Pine Seedlings ◽  
Genes Encoding ◽  
Related Proteins

This study investigated the complex phenotypic and genetic response of Monterey pine (Pinus radiata) seedlings to co-infections by F. circinatum, the causal agent of pine pitch canker disease, and the oomycetes Phytophthora xcambivora and P. parvispora. Monterey pine seedlings were wound-inoculated with each single pathogen and with the combinations F. circinatum/P. xcambivora and F. circinatum/P. parvispora. Initially, seedlings inoculated only with F. circinatum showed less severe symptoms than seedlings co-inoculated or inoculated only with P. xcambivora or P. parvispora. However, 30 days post-inoculation (dpi), all inoculated seedlings, including those inoculated only with F. circinatum, showed severe symptoms with no significant differences among treatments. The transcriptomic profiles of three genes encoding pathogenesis-related proteins, i.e., chitinase (PR3), thaumatin-like protein (PR5), phenylalanine ammonia-lyase (PAL), and the pyruvate decarboxylase (PDC)-encoding gene were analyzed at various time intervals after inoculation. In seedlings inoculated with single pathogens, F. circinatum stimulated the up-regulation of all genes, while between the two oomycetes, only P. xcambivora induced significant up-regulations. In seedlings co-inoculated with F. circinatum and P. xcambivora or P. parvispora none of the genes showed a significant over-expression 4 dpi. In contrast, at 11 dpi, significant up-regulation was observed for PR5 in the combination F. circinatum/P. xcambivora and PDC in the combination F. circinatum/P. parvispora, thus suggesting a possible synergism of multiple infections in triggering this plant defense mechanism.

Effects of pitch canker pathogen on gallery excavation and oviposition by Ips paraconfusus (Coleoptera: Scolytidae)

2002 ◽  
Vol 134 (4) ◽  
pp. 519-528 ◽  
Author(s):  
Andrew J. Storer ◽  
David L. Wood ◽  
Thomas R. Gordon
Keyword(s):  
Pinus Radiata ◽  
Ips Paraconfusus ◽  
Multiple Infections ◽  
Pitch Canker ◽  
Fusarium Circinatum ◽  
Monterey Pine ◽  
Naturally Occurring ◽  
Canker Pathogen ◽  
Negative Effect ◽  
The Mean

AbstractIps paraconfusus Lanier is a vector of the pitch canker fungus, Fusarium circinatum Nirenberg and O’Donnell, in California. Multiple infections of Monterey pine, Pinus radiata D. Don. (Pinaceae), branches and main stems appear to predispose trees to infestation by I. paraconfusus. The effect of cankers produced in response to F. circinatum on oviposition and gallery construction was investigated. Introduction of beetles into artificially induced or naturally occurring cankers was less likely to result in oviposition and resulted in shorter galleries than introductions into logs without cankers. Of all adults that produced eggs, the mean number of eggs per adult was no different in logs with cankers than in canker-free logs; however, the distance across the grain from the introduction point to the first egg was greater for adults introduced into cankers than for adults introduced away from cankers. These results indicate that the pitch canker pathogen has a negative effect on I. paraconfusus, as cankers produced in response to the pathogen are unsuitable for exploitation by the insect.

TRANSMISSION OF THE PITCH CANKER FUNGUS, FUSARIUM SUBGLUTINANS F. SP. PINI, TO MONTEREY PINE, PINUS RADIATA, BY CONE- AND TWIG-INFESTING BEETLES

1996 ◽  
Vol 128 (6) ◽  
pp. 981-994 ◽  
Author(s):  
Kelli Hoover ◽  
David L. Wood ◽  
Andrew J. Storer ◽  
Joseph W. Fox ◽  
William E. Bros
Keyword(s):  
Pinus Radiata ◽  
Insect Vectors ◽  
Beetle Species ◽  
Pitch Canker ◽  
Fusarium Subglutinans ◽  
Experimental Conditions ◽  
Canker Disease ◽  
Average Percentage ◽  
Monterey Pine ◽  
Plant Parts

AbstractConophthorus radiatae Hopkins, Ernobius punctulatus Fall, and Pityophthorus spp. infest cones and twigs of Monterey pines (Pinus radiata D. Don) and thus may be important vectors of the pitch canker fungus Fusarium subglutinans f. sp. pini in the central coast of California. Fifteen percent of 1st-year Monterey pine conelets infested with C. radiatae prior to August 1990 developed pitch canker by May 1991. Conophthorus radiatae, E. punctulatus, and Pityophthorus spp. were dissected from some of these conelets and found carrying F. s. pini. Between June 1990 and May 1991, 16% of 695 randomly selected uninfested 1st-year conelets from a total of 329 separate cone whorls were infested by at least one of the above beetle species, and F. s. pini was isolated from 42% of the attacked conelets. Average percentage contamination of beetles per conelet was highest for adults of Pityophthorus spp. (38%), followed by adults of C. radiatae (33%), larvae of E. punctulatus (24%), and larvae of Pityophthorus spp. (5%). There were significant associations between conelets that contained contaminated C. radiatae, Pityophthorus spp., and/or E. punctulatus and conelets with F. s. pini.Under experimental conditions, C. radiatae and E. punctulatus transmitted the fungus to healthy cones. Ernobius punctulatus required an entrance tunnel by C. radiatae to enter and infect the cone. Artificially wounded cones did not develop pitch canker. Intra- and interspecific transmission of F. s. pini was demonstrated among these beetle species. In infested branch tips without cones, interspecific transmission of F. s. pini between E. punctulatus and Pityophthorus spp. was also demonstrated.The roles of C. radiatae and E. punctulatus as vectors of F. s. pini and of Pityophthorus spp. as potential vectors are discussed in relation to the epidemiology of pitch canker disease. The spread of pitch canker to California’s native pines as well as other conifers may be enhanced by interspecific transmission of F. s. pini between E. punctulatus and C. radiatae in cones and between E. punctulatus and Pityophthorus spp. in branch tips. Ernobius punctulatus provides a pathway for the fungus to potential insect vectors that attack several hosts and a variety of plant parts.

scholarly journals Bioassay Conditions for Infection of Pinus radiata Seedlings with Phytophthora pinifolia Zoospores

Plant Disease ◽  
2015 ◽  
Vol 99 (9) ◽  
pp. 1204-1209 ◽  
Author(s):  
Timothy L. Widmer ◽  
Stephen C. Dodge
Keyword(s):  
United States ◽  
Pinus Radiata ◽  
Tree Species ◽  
Genetic Material ◽  
The United States ◽  
Optimal Conditions ◽  
Monterey Pine ◽  
Pine Seedlings ◽  
Rate Information ◽  
Chamber Temperature

Phytophthora pinifolia is known to cause a devastating disease on Monterey pine in Chile. Although this pathogen is not yet present in the United States, there is reason for concern. The main source of Monterey pine genetic material is found in California and there is potential for other important tree species to be hosts. The study presented here was conducted to develop a method to produce zoospores and determine optimal conditions for infection to be used in future host range studies. Abundant zoospores were produced when agar plugs containing P. pinifolia mycelia were ground into suspension prior to transfer in a solution of carrot broth. These zoospores then were used to inoculate Monterey pine seedlings under various conditions. Infected plants displayed necrotic crowns and stems, often resulting in wilting of the seedling. Consistent infection occurred when seedlings were wounded by trimming needles prior to inoculation and exposure of inoculated seedlings to constant dew for 5 days. Dew chamber temperature (15, 20, or 25°C) did not affect the infection rate. Information obtained from this study will be useful in screening other hosts for susceptibility to P. pinifolia infection.

scholarly journals Inducible Defense Mechanism against Nitric Oxide in Candida albicans

2004 ◽  
Vol 3 (3) ◽  
pp. 715-723 ◽  
Author(s):  
Breanna D. Ullmann ◽  
Hadley Myers ◽  
Wiriya Chiranand ◽  
Anna L. Lazzell ◽  
Qiang Zhao ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Candida Albicans ◽  
Defense Mechanism ◽  
Immune Cell ◽  
Opportunistic Pathogen ◽  
Mrna Levels ◽  
Genes Encoding ◽  
Nitrogen Radicals ◽  
Related Proteins ◽  
Type Strains

ABSTRACT The yeast Candida albicans is an opportunistic pathogen that threatens patients with compromised immune systems. Immune cell defenses against C. albicans are complex but typically involve the production of reactive oxygen species and nitrogen radicals such as nitric oxide (NO) that damage the yeast or inhibit its growth. Whether Candida defends itself against NO and the molecules responsible for this defense have yet to be determined. The defense against NO in various bacteria and the yeast Saccharomyces cerevisiae involves an NO-scavenging flavohemoglobin. The C. albicans genome contains three genes encoding flavohemoglobin-related proteins, CaYHB1, CaYHB4, and CaYHB5. To assess their roles in NO metabolism, we constructed strains lacking each of these genes and demonstrated that just one, CaYHB1, is responsible for NO consumption and detoxification. In C. albicans, NO metabolic activity and CaYHB1 mRNA levels are rapidly induced by NO and NO-generating agents. Loss of CaYHB1 increases the sensitivity of C. albicans to NO-mediated growth inhibition. In mice, infections with Candida strains lacking CaYHB1 still resulted in lethality, but virulence was decreased compared to that in wild-type strains. Thus, C. albicans possesses a rapid, specific, and highly inducible NO defense mechanism involving one of three putative flavohemoglobin genes.

ASSOCIATION BETWEEN A NATIVE SPITTLEBUG (HOMOPTERA: CERCOPIDAE) ON MONTEREY PINE AND AN INTRODUCED TREE PATHOGEN WHICH CAUSES PITCH CANKER DISEASE

1998 ◽  
Vol 130 (6) ◽  
pp. 783-792 ◽  
Author(s):  
Andrew J. Storer ◽  
David L. Wood ◽  
Karen R. Wikler ◽  
Thomas R. Gordon
Keyword(s):  
Pinus Radiata ◽  
Spore Suspension ◽  
Field Observations ◽  
Pitch Canker ◽  
Canker Disease ◽  
Feeding Sites ◽  
Monterey Pine ◽  
Canker Pathogen ◽  
Monterey Peninsula

AbstractJuvenile Monterey pines, Pinus radiata D. Don (Pinaceae), in a native stand on the Monterey Peninsula, California, exhibited wilted green shoots in the spring of 1996. The pitch canker fungus, Fusarium subglutinans (Wollenweb. & Reinking) P.E. Nelson, Toussoun & Marasas f.sp. pini, was subsequently isolated from 95% of these shoots. Spittle masses produced by Aphrophora canadensis Walley were observed on the symptomless shoots of many of these trees. The pitch canker fungus was isolated from the feeding sites of this insect on 55% of symptomless shoots, and from shoot sections adjacent to these feeding sites on 29% of the shoots. Shoots with spittlebugs feeding on them in May 1996 were more likely to develop pitch canker disease by September 1996 and March 1997 than shoots without spittlebugs. Shoots with spittle masses in March 1997 were as likely to develop pitch canker disease by May and August 1997 as shoots without spittle masses, but the origin of the infection was most likely where A. canadensis feeding had taken place. In a controlled test, the incidence of pitch canker on shoots of potted Monterey pines was dependent on the presence of a spittlebug and a spore suspension of the pathogen. Thus, both field observations and controlled studies show an association between native A. canadensis and the introduced pitch canker pathogen. The role of A. canadensis in the epidemiology of pitch canker disease remains to be determined.

scholarly journals Role of Suillus placidus in Improving the Drought Tolerance of Masson Pine (Pinus massoniana Lamb.) Seedlings

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 332
Author(s):  
Min Li ◽  
Haoyun Wang ◽  
Xizhou Zhao ◽  
Zhongke Lu ◽  
Xueguang Sun ◽  
...  
Keyword(s):  
Drought Stress ◽  
Defense Mechanism ◽  
Southern China ◽  
Dry Weight ◽  
Pinus Massoniana ◽  
Photosynthetic Performance ◽  
Ectomycorrhizal Fungus ◽  
Severe Drought ◽  
Masson Pine ◽  
Pine Seedlings

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.

Dendrogeochemistry and soil geochemistry applied to exploration for alkalic Cu-Au porphyry mineralization under cover at the Racecourse prospect, NSW, Australia

2021 ◽  
Vol 59 (5) ◽  
pp. 1167-1186
Author(s):  
Cole McGill ◽  
Daniel Layton-Matthews ◽  
T. Kurt Kyser ◽  
Matthew I. Leybourne ◽  
Paul Polito ◽  
...  
Keyword(s):  
Pinus Radiata ◽  
Size Fraction ◽  
Ring Width ◽  
Isotopic Signature ◽  
Soil Samples ◽  
Soil Geochemistry ◽  
Tree Roots ◽  
Monterey Pine ◽  
Geophysical Surveys ◽  
Transverse Zone

ABSTRACT The Racecourse Cu-Au porphyry prospect is found within the Macquarie Arc of the Lachlan Fold Belt, in the Lachlan Transverse Zone, a cross-arc structure hosting significant world-class mineralization, including the Cadia and Northparks districts. Several geochemical and geophysical surveys of the prospect have been complimented by a total of 19,819 m of drilling, with only four holes reaching a depth greater than 300 m. Positive lithogeochemistry (fertility indices, comparisons with the Cadia and Northparks systems) subtle alteration, and mineralized intercepts indicate heightened mineral potential, yet the prospect has lacked a comprehensive geochemical survey outlining the extent of the mineralized target at surface. Soil samples and Monterey pine (Pinus radiata) tree cores were collected above and distal to mineralization intercepted by prior drilling in order to outline the ore deposit footprint and test the viability of dendrogeochemistry as an exploration tool for porphyry Cu mineralization. Ultimately, this study documented the spatial extent of the Racecourse target and identified potential areas for additional Cu mineralization. Soil samples were separated with the <250 μm size fraction analyzed and show distinct anomalous populations of Au, Cu, Mo, Pb, and Zn above prior drilling. Tree cores were collected by increment borer and tree rings of the Pinus radiata were counted and measured, with an age interval of 2003–2008 exhibiting the least ring-width variability chosen to chemically analyze. Selected intervals were digested and analyzed and have elevated Cu, Mo, and Zn in an area that overlaps a previously drilled soil anomaly, whereas an anomaly in the southwest of the survey area documents a Cu, Pb anomaly corresponding to localized faulting and tertiary basalt subcrop. Tree roots are directly tapping chemical variability at depth, aided via metal mobilization through faulted fluid conduits. Lead isotope ratios from the Pinus radiata identify distinct groups of lead spatially associated with discrete metal anomalies of varied lithological ages. At the Racecourse target, anomalous Pinus radiata samples yield a similar isotopic signature to the faulted southwestern anomaly, potentially linking the source of these two metal anomalies. When these results are integrated with the current understanding of the mineralized body, geochemical media suggest that mineralization may continue down-plunge at depth.

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