Increasing temperature elevates the variation and spatial differentiation of pesticide tolerance in a plant pathogen

Abstract

Climate change and pesticide resistance are two of the most imminent challenges human society is facing today. Knowledge of how the evolution of pesticide resistance may be affected by climate change such as increasing air temperature on the planet is important for agricultural production and ecological sustainability in the future but is lack in scientific literatures reported from empirical research. Here, we used the azoxystrobin‐Phytophthora infestans interaction in agricultural systems to investigate the contributions of environmental temperature to the evolution of pesticide resistance and infer the impacts of global warming on pesticide efficacy and future agricultural production and ecological sustainability. We achieved this by comparing azoxystrobin sensitivity of 180 P. infestans isolates sampled from nine geographic locations in China under five temperature schemes ranging from 13 to 25°C. We found that local air temperature contributed greatly to the difference of azoxystrobin tolerance among geographic populations of the pathogen. Both among‐population and within‐population variations in azoxystrobin tolerance increased as experimental temperatures increased. We also found that isolates with higher azoxystrobin tolerance adapted to a broader thermal niche. These results suggest that global warming may enhance the risk of developing pesticide resistance in plant pathogens and highlight the increased challenges of administering pesticides for effective management of plant diseases to support agricultural production and ecological sustainability under future thermal conditions.

Effector Avr4 in Phytophthora infestans Escapes Host Immunity Mainly Through Early Termination

“…Ningxia, Guizhou, and Yunnan are among the top potato production regions in China, with >0.6 million annual hectares in each of the regions, whereas Fujian only grows ~1/10 acreage of each of the regions. The finding of the highest genetic variation in the P. infestans Avr4 gene from Fujian is unexpected but consistent with previous results derived from other effector genes (e.g., Avr2 and AVR3a), phenotypic traits (fungicide resistance and aggressiveness), and ecological data (e.g., growth rate and ultraviolet tolerance) of the pathogen (Qin et al, 2016;Yang et al, 2018Yang et al, , 2020Wu et al, 2019Wu et al, , 2020Lurwanu et al, 2021). Unlike Guizhou, Ningxia, Yunnan, and many other regions where well-established seed production systems can ensure the adequate supply for own use, potato in Fujian relies on imported seeds from other parts of China, increasing the chance of bringing novel variation into the region and supporting the theory that anthropogenic activities play a critical role in facilitating the evolution of plant pathogens in agricultural systems.…”

Altitudinal Heterogeneity of UV Adaptation in Phytophthorainfestans Is Associated with the Spatial Distribution of a DNA Repair Gene

“…This was achieved by taking a piece of mycelium from a sporulating leave and inoculating it onto a rye B agar plate supplemented with ampicillin (100 µg/mL) and rifampin (10 µg/mL). The isolates were purified by sub-culturing twice and were genotyped using a combination of SSR nuclear genome assays [42,43], restriction enzyme-PCR amplification of mitochondrial genomes [44], mating type assessments [45], and a sequence analysis of functional genes (β-tubulin, Cox1 and Avr3a) [46], as described previously [47][48][49]. A total of 140 distinct genotypes, with 20 from each of the field populations, were selected for further study.…”

Single Amino Acid Substitution in the DNA Repairing Gene Radiation-Sensitive 4 Contributes to Ultraviolet Tolerance of a Plant Pathogen

“…A total of 140 distinct genotypes with 20 from each of the seven field populations were selected for the study. Details of P. infestans collection, isolation, purification, and molecular characterization of these isolates were described in the previous publications ( Qin et al, 2016 ; Yang et al, 2016 ; Wu et al, 2020 ; Lurwanu et al, 2021 ).…”