Pseudothecia of Swiss needle cast fungus, <i>Phaeocryptopus gaeumannii</i>, physically block stomata of Douglas fir, reducing CO<sub>2</sub> assimilation

Manter, Daniel K.; Bond, Barbara J.; Kavanagh, Kathleen L.; Rosso, Pablo; Filip, Gregory M.

doi:10.1046/j.1469-8137.2000.00779.x

Cited by 76 publications

(59 citation statements)

References 26 publications

(24 reference statements)

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“…Occlusion of the stomata by pseudothecia of P. gaeumannii impedes gas exchange and regulation of transpiration, causing impaired photosynthetic activity, and is considered the primary mechanism of pathogenicity (Manter et al 2000(Manter et al , 2003. Estimates of the effect of P. gaeumannii on CO 2 assimilation indicate that occlusion of ∼25% of stomata results in overall negative needle carbon budgets, i.e.…”

Section: Discussionmentioning

confidence: 99%

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Stone

Hood²,

Watt³

et al. 2007

Austral. Plant Pathol.

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Abstract. Phaeocryptopus gaeumannii, the causal agent of Swiss needle cast disease, is widely distributed throughout New Zealand, where the disease may cause significant growth losses in Douglas-fir (Pseudotsuga menziesii) plantations. In western Oregon, where the pathogen is native, pathogen abundance and disease severity are correlated with mean daily winter temperatures and spring moisture, enabling the development of climate-based disease prediction models. The distribution of P. gaeumannii and severity of Swiss needle cast was surveyed in 16 Douglas-fir plantations throughout New Zealand in 2005. Retention of foliage was assessed in the field and samples of 1-and 2-year-old needles were collected for assessment of P. gaeumannii abundance. Foliage retention and abundance of P. gaeumannii varied across sites. Less colonisation by P. gaeumannii and greater needle retention was found in the South Island. Abundance of P. gaeumannii was found to be positively correlated with August minimum temperature and June average temperature, and showed a similar relationship to winter temperature as observed in western Oregon. These data will be used to derive a disease prediction model for Swiss needle cast in New Zealand that can be used to guide further research and provide short-and long-term disease risk predictions and cost/benefit analyses.

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Section: Discussionmentioning

confidence: 99%

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Stone

Hood²,

Watt³

et al. 2007

Austral. Plant Pathol.

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“…This was carefully removed with a soft tissue prior to preparation for XRMA. Vaseline application is a nontoxic method for stopping water loss from leaves and other plant tissues (McIntyre, 1994;Manter et al, 2000).…”

Section: Strontium and Rubidium Uptake Experimentsmentioning

confidence: 99%

Processes Modulating Calcium Distribution in Citrus Leaves. An Investigation Using X-Ray Microanalysis with Strontium as a Tracer

Storey

Leigh

2004

Plant Physiology

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Citrus leaves accumulate large amounts of calcium that must be compartmented effectively to prevent stomatal closure by extracellular Ca 21 and interference with Ca 21 -based cell signaling pathways. Using x-ray microanalysis, the distribution of calcium between vacuoles in different cell types of leaves of rough lemon (Citrus jambhiri Lush.) was investigated. Calcium was accumulated principally in palisade, spongy mesophyll, and crystal-containing idioblast cells. It was low in epidermal and bundle sheath cells. Potassium showed the reverse distribution. Rubidium and strontium were used as tracers to examine the pathways by which potassium and calcium reached these cells. Comparisons of strontium and calcium distribution indicated that strontium is a good tracer for calcium, but rubidium did not mirror the potassium distribution pattern. The amount of strontium accumulated was highest in palisade cells, lowest in bundle sheath and epidermal cells, and intermediate in the spongy mesophyll. Accumulation of strontium in palisade and spongy mesophyll was accompanied by loss of potassium from these cells and its accumulation in the bundle sheath. Strontium moved apoplastically from the xylem to all cell types, and manipulation of water loss from the adaxial leaf surface suggested that diffusion is responsible for strontium movement to this side of the leaf. The results highlight the importance of palisade and spongy mesophyll as repositories for calcium and suggest that calcium distribution between different cell types is the result of differential rates of uptake. This tracer technique can provide important information about the ion uptake and accumulation properties of cells in intact leaves.Studies of the elemental composition of vacuoles in leaf cells have shown that nutrients are asymmetrically distributed between different cell types (Leigh and Tomos, 1993;Leigh, 2001). This has been studied in most detail in barley (Hordeum vulgare), where phosphorus is largely restricted to mesophyll cells, while calcium and chlorine are mainly in epidermal cells, with potassium and nitrate more evenly distributed (Dietz et al., 1992;Leigh and Storey, 1993;Williams et al., 1993;Fricke et al., 1994). Other species also show differences in vacuole composition between different cell types. In wheat, the patterns of distribution are similar to those in barley (Hodson and Sangster, 1988), but in other species they are not. In Lupinus luteus leaflets, phosphorus was found at higher concentrations in epidermal cells than in palisade and spongy mesophyll (Treeby et al., 1987), while in sorghum, phosphorus was highest in bundle sheath cells and lowest in the adaxial epidermis, these latter cells containing the highest calcium levels (Boursier and Läuchli, 1989). In the calcicoles, Centaurea scabiosa and Leontodon hispidus, calcium was highest in palisade, spongy mesophyll, and trichomes, and was excluded from the epidermal cells (De Silva et al., 1996).Although the physiological reasons for these distributions remain largely unexpla...

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“…Later studies of SNC disease physiology revealed that these symptoms are caused by reduced gas exchange in the needles due to the occlusion of the stomata by ascocarps (pseudothecia) produced by this fungus. This blockage of the stomata leads to a reduction in carbon assimilation proportional to the percentage of total stomates occupied by pseudothecia [3] Abscission occurs when a needle ceases to function as a carbon source [4]. Regional SNC aerial surveys conducted annually since 1996 have documented gradual expansions in the area affected by the disease and in…”

Section: Introductionmentioning

confidence: 99%

Assessments of Population Structure, Diversity, and Phylogeography of the Swiss Needle Cast Fungus (Phaeocryptopus gaeumannii) in the U.S. Pacific Northwest

Bennett

Stone

2016

Forests

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Swiss needle cast (SNC) is a foliar disease of Douglas-fir (Pseudotsuga menziesii) caused by Phaeocryptopus gaeumannii (Rohde) Petrak. This fungus is endemic to western North America, where it has historically had little impact in native forests. However, increasing disease severity in western Oregon since the 1990s has prompted renewed interest in P. gaeumannii and SNC. For this study, we analyze multilocus microsatellite genotypes from 482 single-spore isolates from 68 trees across 14 sites in the western Coast Range of Oregon and southwestern Washington. This study assesses genotypic variation and genetic structure at several levels of population hierarchy. Despite the observation that most of the genetic variation occurred within subpopulations, our analyses detected significant differentiation at all hierarchical levels. Clustering among the 482 isolates based on genetic distance clearly supports the existence of two previously described cryptic lineages of P. gaeumannii in the western United States. The two lineages occur in varying proportions along latitudinal and longitudinal gradients in western Oregon and Washington, suggesting a relationship between climate and phylogeography. Sites near Tillamook, Oregon, where SNC is most severe, consist of sympatric subpopulations in which the two lineages comprise roughly equal proportions.

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Pseudothecia of Swiss needle cast fungus, Phaeocryptopus gaeumannii, physically block stomata of Douglas fir, reducing CO₂ assimilation

Cited by 76 publications

References 26 publications

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Processes Modulating Calcium Distribution in Citrus Leaves. An Investigation Using X-Ray Microanalysis with Strontium as a Tracer

Assessments of Population Structure, Diversity, and Phylogeography of the Swiss Needle Cast Fungus (Phaeocryptopus gaeumannii) in the U.S. Pacific Northwest

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Pseudothecia of Swiss needle cast fungus, Phaeocryptopus gaeumannii, physically block stomata of Douglas fir, reducing CO2 assimilation

Cited by 76 publications

References 26 publications

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Processes Modulating Calcium Distribution in Citrus Leaves. An Investigation Using X-Ray Microanalysis with Strontium as a Tracer

Assessments of Population Structure, Diversity, and Phylogeography of the Swiss Needle Cast Fungus (Phaeocryptopus gaeumannii) in the U.S. Pacific Northwest

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Pseudothecia of Swiss needle cast fungus, Phaeocryptopus gaeumannii, physically block stomata of Douglas fir, reducing CO₂ assimilation