Drought × disease interaction in Eucalyptus globulus under Neofusicoccum eucalyptorum infection

Abstract

Eucalyptus species are widely spread over the world, being extensively planted and exploited by industries. Drought and pathogens are known to affect the establishment and productivity of Eucalyptus plantations worldwide. The aim of this work was to evaluate the pathogenicity of Neofusicoccum eucalyptorum in drought-stressed and well-watered E. globulus plants. The effect of a previous drought priming step and the role of water status at the time of inoculation were evaluated. Lesion length, plant growth and physiological parameters (relative water content, water potential, photosynthetic pigments and lipid peroxidation) were determined. The results indicate that water-stressed plants were more susceptible to N. eucalyptorum than non-stressed ones. However, this response was particularly relevant when the plants were inoculated while water limitation was already occurring. Moreover, drought-primed plants were slightly more resistant to fungal infection than the non-primed ones. This study reinforces the importance of exploring drought 9 disease interaction in Eucalyptus and the underlying physiological responses involved in plant performance.

Impact of Botryosphaeria, Diplodia and Neofusicoccum species on two Eucalyptus species and a hybrid: From pathogenicity to physiological performance

“…Moreover, this finding aligns with the concept that Botryosphaeriaceae species are latent pathogens that can live in plants without causing any symptoms until some external factor or alteration in the plant-pathogen interaction induces a switch in the lifestyle (Barradas et al, 2018). However, additional research should be conducted to explore the plant-pathogen interaction mechanisms that remain underexplored but might shed light on the confounding responses detected here.…”

“…It is recognized that tolerance to stress factors such as drought differs among and within Eucalyptus species (Correia et al, 2014;Granda et al, 2014;McKiernan et al, 2016). Félix et al, 2017;Barradas et al, 2018). Previous studies assessed pathogenicity/aggressiveness of Botryosphaeriaceae species based on traits such as lesion length (Barradas et al, 2016;Li et al, 2018;Pavlic, Slippers, Coutinho, & Wingfield, 2007;Pérez, Wingfield, Slippers, Altier, & Blanchette, 2010;Rodas, Slippers, Gryzenhout, & Wingfield, 2009;Smith, Kemp, & Wingfield, 1994), while the physiological status of the infected plants remains poorly studied (e.g.…”

“…Previous studies assessed pathogenicity/aggressiveness of Botryosphaeriaceae species based on traits such as lesion length (Barradas et al, 2016;Li et al, 2018;Pavlic, Slippers, Coutinho, & Wingfield, 2007;Pérez, Wingfield, Slippers, Altier, & Blanchette, 2010;Rodas, Slippers, Gryzenhout, & Wingfield, 2009;Smith, Kemp, & Wingfield, 1994), while the physiological status of the infected plants remains poorly studied (e.g. Félix et al, 2017;Barradas et al, 2018). Morpho-physiological parameters that include growth, gas exchange and photosynthetic efficiency, among others, represent good indicators of plant responses to biotic factors (Berger, Sinha, & Roitsch, 2007;Linaldeddu, Sirca, Spano, & Franceschini, 2009).…”

Monoterpene responses to interacting effects of drought stress and infection by the fungus Heterobasidion parviporum in two clones of Norway spruce (Picea abies)

“…A combination of mass inoculation (Leptographium wingfieldii) and drought stress resulted in a dramatic loss of stem hydraulic conductivity in Pinus sylvestris that was paralleled by conspicuous damage to the sapwood (Croisé et al, 2001). Water-stressed plants of Eucalyptus globulus were more susceptible to Neofusicoccum eucalyptorum than nonstressed ones, drought-primed plants being slightly less susceptible to the attack of this pathogenic fungus than the non-primed ones (Barradas et al, 2018). In addition to drought, other factors triggered by climate change may favour certain pathogens, i.e., warming temperature, pathogen migration and vegetation shift (La Porta et al, 2008).…”

Mild water stress-induced priming enhance tolerance to Rosellinia necatrix in susceptible avocado rootstocks

“…water stress, chemical compounds [14,15]) stress episodes. This priming-induced tolerance seems to be associated with a more rapid and robust activation of cellular defense responses in primed plants compared to non-primed ones [11,12,16]. Although the mechanisms underlying the induction of the priming state are complex and diverse [17], it is well known that plant stress responses to biotic or abiotic factors share common pathways [18,19] and even crosstolerance can be achieved [20,21].…”