Adaptation of pathogens to their local plant host, Silphium integrifolium, along a precipitation gradient

Abstract

Empirical evidence of the influence of climate on plant-pathogen coevolution is limited but crucial to understand, as anthropogenic pressures including fragmentation and climate change threaten biodiversity. In this study, we tested patterns of plant-pathogen coevolution using Silphium integrifolium Michx., a native tallgrass prairie species that is undergoing domestication, and its foliar pathogens. We collected seeds from four native prairie remnants from each of three regions along an east-west precipitation gradient in central North America and used these to create three common gardens in each region.

Distinguishing Abiotic from Biotic Stressors in Perennial Grain Crops: Nutrient Deficiency Symptoms in Silphium integrifolium and Thinopyrum intermedium

“…This study was designed to build tools to identify common nutrient stresses and differentiate them from diseases. This is especially relevant in silflower, where recently identified viruses (Dahlia mosaic virus; Dahlia common mosaic virus; and an endogenous plant pararetroviral sequence-DvEPRS) and herbicide (2,4-D and Dicamba) sensitivity (Figure 8) described as Silphium clear vein (SCV) were initially confounded with potentially similar symptoms of B deficiency [19]. SCV is characterized by wide, clear veins; twisting of leaves; yellowing at the leaf tips; and mottling.…”

“…The early external symptoms of some silflower diseases are not always clear and can be confused with responses to abiotic stress. Silflower plants with Silphium clear vein (SCV) disease [19] were initially believed to be suffering from a B deficiency due to the similarity in symptoms. B-deficient plants can experience leaf-width reduction and constriction, yellowing near the leaf tip, and dying of leaves near the edges.…”

Local adaptation of both plant and pathogen: an arms-race compromise in switchgrass rust

“…As such, a number of studies have uncovered local adaptation in host-associated microbes (reviewed in (Kraemer and Boynton 2017), including a number in rust-plant pathosystems (ex. Thrall and Burdon 2002; Laine et al 2014; Cassetta et al 2023). However, it is rarer to uncover a host-pathogen system wherein the host has been shown to be locally adapted to abiotic environmental conditions at a similar scale as its locally adapted pathogen.…”

“…An alternate method may be used to test for local adaptation in parasites, for which we propose the term “host reciprocal transplant.” Transplanting host genotypes into regions with endemic parasite populations, rather than transplanting parasites between host populations, allows for local adaptation testing that avoids many pitfalls of parasite transplantation (Laine 2007), such as ethical and legal barriers to moving parasites to new regions. Though this method has received less attention in local adaptation theory, it has been used as a strategy in multiple experiments (Davelos et al 1996; Busby et al 2014; Cassetta et al 2023; Laine et al 2007). However, there are challenges to this method as well.…”