Effect of fungal infection on leaf gas-exchange and chlorophyll fluorescence in <i>Quercus ilex</i>

Omari, Bouchra El; Fleck, Isabel; Aranda, Xavier; Moret, Asumpció; MartíNadal,

doi:10.1051/forest:2001116

Cited by 14 publications

(8 citation statements)

References 33 publications

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“…Picual/D pathotype infected plants could be also expected according to previous results obtained with trees under water stress [39] , [58] . Depression in photosynthetic activity mainly due to drought in plants inoculated with wilting fungi has been described in several pathosystems, including potato infected with V. dahliae [56] , tomato infected with Verticillium albo-atrum [59] , and Quercus ilex infected with Cryphonectria parasitica [60] . Chlorophyll content in leaves estimated by SPAD readings was inversely correlated with disease severity, as previously found in potato plants infected with V. dahliae [61] .…”

Section: Discussionmentioning

confidence: 99%

Soil Temperature Determines the Reaction of Olive Cultivars to Verticillium dahliae Pathotypes

et al. 2014

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BackgroundDevelopment of Verticillium wilt in olive, caused by the soil-borne fungus Verticillium dahliae, can be influenced by biotic and environmental factors. In this study we modeled i) the combined effects of biotic factors (i.e., pathotype virulence and cultivar susceptibility) and abiotic factors (i.e., soil temperature) on disease development and ii) the relationship between disease severity and several remote sensing parameters and plant stress indicators.MethodologyPlants of Arbequina and Picual olive cultivars inoculated with isolates of defoliating and non-defoliating V. dahliae pathotypes were grown in soil tanks with a range of soil temperatures from 16 to 32°C. Disease progression was correlated with plant stress parameters (i.e., leaf temperature, steady-state chlorophyll fluorescence, photochemical reflectance index, chlorophyll content, and ethylene production) and plant growth-related parameters (i.e., canopy length and dry weight).FindingsDisease development in plants infected with the defoliating pathotype was faster and more severe in Picual. Models estimated that infection with the defoliating pathotype was promoted by soil temperatures in a range of 16 to 24°C in cv. Picual and of 20 to 24°C in cv. Arbequina. In the non-defoliating pathotype, soil temperatures ranging from 16 to 20°C were estimated to be most favorable for infection. The relationship between stress-related parameters and disease severity determined by multinomial logistic regression and classification trees was able to detect the effects of V. dahliae infection and colonization on water flow that eventually cause water stress.ConclusionsChlorophyll content, steady-state chlorophyll fluorescence, and leaf temperature were the best indicators for Verticillium wilt detection at early stages of disease development, while ethylene production and photochemical reflectance index were indicators for disease detection at advanced stages. These results provide a better understanding of the differential geographic distribution of V. dahliae pathotypes and to assess the potential effect of climate change on Verticillium wilt development.

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Section: Discussionmentioning

confidence: 99%

Soil Temperature Determines the Reaction of Olive Cultivars to Verticillium dahliae Pathotypes

et al. 2014

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“…Analogously, in plant–pathogen interactions, pathogen spores dispersed by water, wind, or by insects settle on a plant and form hydrophobic interactions with the waxy polymers on leaf surface. Ultimately, the airborne pathogen enters the leaf intracellular space via stomata (El Omari et al, 2001; Prats et al, 2007). The density of pathogen propagules determines the number of stomatal entry points within the given leaf, but the initial response remains characteristically localized unless the pathogen density is very high.…”

Section: Induced Volatiles In Plant Defense Responses: From Qualitatimentioning

confidence: 99%

Quantitative patterns between plant volatile emissions induced by biotic stresses and the degree of damage

Niinemets¹,

Kännaste²,

Copolovici³

2013

Front. Plant Sci.

203

168

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Plants have to cope with a plethora of biotic stresses such as herbivory and pathogen attacks throughout their life cycle. The biotic stresses typically trigger rapid emissions of volatile products of lipoxygenase (LOX) pathway (LOX products: various C6 aldehydes, alcohols, and derivatives, also called green leaf volatiles) associated with oxidative burst. Further a variety of defense pathways is activated, leading to induction of synthesis and emission of a complex blend of volatiles, often including methyl salicylate, indole, mono-, homo-, and sesquiterpenes. The airborne volatiles are involved in systemic responses leading to elicitation of emissions from non-damaged plant parts. For several abiotic stresses, it has been demonstrated that volatile emissions are quantitatively related to the stress dose. The biotic impacts under natural conditions vary in severity from mild to severe, but it is unclear whether volatile emissions also scale with the severity of biotic stresses in a dose-dependent manner. Furthermore, biotic impacts are typically recurrent, but it is poorly understood how direct stress-triggered and systemic emission responses are silenced during periods intervening sequential stress events. Here we review the information on induced emissions elicited in response to biotic attacks, and argue that biotic stress severity vs. emission rate relationships should follow principally the same dose–response relationships as previously demonstrated for different abiotic stresses. Analysis of several case studies investigating the elicitation of emissions in response to chewing herbivores, aphids, rust fungi, powdery mildew, and Botrytis, suggests that induced emissions do respond to stress severity in dose-dependent manner. Bi-phasic emission kinetics of several induced volatiles have been demonstrated in these experiments, suggesting that next to immediate stress-triggered emissions, biotic stress elicited emissions typically have a secondary induction response, possibly reflecting a systemic response. The dose–response relationships can also vary in dependence on plant genotype, herbivore feeding behavior, and plant pre-stress physiological status. Overall, the evidence suggests that there are quantitative relationships between the biotic stress severity and induced volatile emissions. These relationships constitute an encouraging platform to develop quantitative plant stress response models.

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“…In addition to herbivorous arthropods, pathogens (Hood et al 1990;Osmond et al 1990;Faeth 1992) and physical damage (Hoad et al 1998;Hunter and Forkner 1999) can further reduce photosynthesis in natural ecosystems. For example, the reduction of stomatal conductance and photosynthesis by fungal infection of oak leaves directly reduces growth (Luque et al 1999;El Omari et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Comparison of photosynthetic damage from arthropod herbivory and pathogen infection in understory hardwood saplings

et al. 2006

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Arthropods and pathogens damage leaves in natural ecosystems and may reduce photosynthesis at some distance away from directly injured tissue. We quantified the indirect effects of naturally occurring biotic damage on leaf-level photosystem II operating efficiency (Phi(PSII)) of 11 understory hardwood tree species using chlorophyll fluorescence and thermal imaging. Maps of fluorescence parameters and leaf temperature were stacked for each leaf and analyzed using a multivariate method adapted from the field of quantitative remote sensing. Two tree species, Quercus velutina and Cercis canadensis, grew in plots exposed to ambient and elevated atmospheric CO(2) and were infected with Phyllosticta fungus, providing a limited opportunity to examine the potential interaction of this element of global change and biotic damage on photosynthesis. Areas surrounding damage had depressed Phi(PSII )and increased down-regulation of PSII, and there was no evidence of compensation in the remaining tissue. The depression of Phi(PSII) caused by fungal infections and galls extended >2.5 times further from the visible damage and was approximately 40% more depressed than chewing damage. Areas of depressed Phi(PSII) around fungal infections on oaks growing in elevated CO(2) were more than 5 times larger than those grown in ambient conditions, suggesting that this element of global change may influence the indirect effects of biotic damage on photosynthesis. For a single Q. velutina sapling, the area of reduced Phi(PSII) was equal to the total area directly damaged by insects and fungi. Thus, estimates based only on the direct effect of biotic agents may greatly underestimate their actual impact on photosynthesis.

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Effect of fungal infection on leaf gas-exchange and chlorophyll fluorescence in Quercus ilex

Cited by 14 publications

References 33 publications

Soil Temperature Determines the Reaction of Olive Cultivars to Verticillium dahliae Pathotypes

Soil Temperature Determines the Reaction of Olive Cultivars to Verticillium dahliae Pathotypes

Quantitative patterns between plant volatile emissions induced by biotic stresses and the degree of damage

Comparison of photosynthetic damage from arthropod herbivory and pathogen infection in understory hardwood saplings

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