A decade of hidden phytoplasmas unveiled through citizen science

Abstract

Climate change is impacting agriculture in many ways, and a contribution from all is required to reduce the imminent loses related to it. Recently, it has been showed that citizen science could be a way to trace the impact of climate change. However, how can citizen science be applied in plant pathology? Here, using as an example a decade of phytoplasma-related diseases reported by growers, agronomists, citizens in general, and confirmed by a government laboratory, we explore a new way of valuing plant pathogens monitoring data deriving from land-users or stakeholders. Through this collaboration we found that in the last decade thirty-four hosts have been affected by phytoplasmas, nine, thirteen and five of these plants were, for the first time, reported phytoplasma hosts in Eastern Canada, in Canada and worldwide, respectively. Another finding of great impact is the first report of a ′Ca. P. phoenicium′-related strain in Canada, while ′Ca. P. pruni′ and ′Ca. P. pyri′ was reported for the first time in Eastern Canada. These findings will have a great impact in the management of phytoplasmas and their insect vectors. Using these insect-vectored bacterial pathogens, we show the needs of new strategies that allow a fast and accurate communication between concerned citizens and those institutions confirming their observations.

Potential impact of climate change on Nearctic leafhopper distribution and richness in North America

“…In this region, 38 leafhopper species have been identified as vectors or suspected vectors of phytoplasmas affecting horticultural, fruit, and field crops 33,34,38–40 . However, recent findings by our group indicate a tripling incidence of phytoplasma diseases in the Nearctic over the past decade 30 . This trend suggests several potential factors: ( i ) advancements in molecular diagnostic methods and novel detection technologies for phytoplasmas 41,42 ; ( ii ) a rise in the abundance of leafhopper vectors 31 ; ( iii ) the probable existence of yet-to-be-identified highly efficient vectors 22,39,43,44 ; and ( iv ) an expansion of the geographic range of leafhopper vectors 23 .…”

“…Over 100 leafhopper species carry phytoplasmas linked to more than 600 diseases affecting a thousand plant species worldwide 12,[27][28][29] . Typical symptoms of phytoplasmas diseases include phyllody, virescence, stunt, witches' broom, fruits appearing as green flowers, and small, curly, and red leaves 22,30 . Examples of such economically damaging diseases in commercial crops include aster yellows in canola 31 , bushy stunt in corn 32 , false blossom in berries 33,34 , green petal in strawberries 22 , and grapevine yellows (Flavescence dorée and Bois noir) in grapevines 35,36 .…”

Can leafhoppers help us trace the impact of climate change on agriculture?

“…Leafhoppers (Cicadellidae) are a group of phloem-, xylem-and mesophyll-feeding insects that includes more than 20,000 described species and is the second-largest hemipteran family in the world (Stiller 2009). These insects are also well-known vectors of viral and bacterial diseases affecting a wide range of economically and ecologically important crops (Weintraub & Beanland, 2006;Brochu et al, 2023).…”

“…How can these effects be quantified in agriculture and plant-vector-pathogen interactions? In a recent study, it was determined that, only in the province of Québec, the number of hosts affected by phytoplasma has quintupled in the last decade (Brochu et al, 2023), evidence that the number of vectors might have increased, that new leafhopper species could be contributing to the spread of the pathogens, and/or that the management strategies used to control the vectors are not successful.…”

Leafhoppers as vectors of phytoplasma diseases in Canadian berry crops: a review in the face of climate change

“…In Canada and the United States of America, several diseases, such as grapevine yellows and blueberry stunt diseases, have been associated with phytoplasma strains transmitted by known leafhopper species (Olivier et al 2014, Davis et al 2015). However, the number of hosts affected by phytoplasmas in this geographic region has tripled in the last decade, indicating either an increase in the abundance of leafhopper vectors or the presence of yet-to-be-identified vectors (Brochu et al 2023). Additionally, access to new technologies and improved molecular diagnostic methods has been crucial in the increasing discovery of diseases associated with phytoplasmas (Pérez-López et al 2018, Hammond et al 2021).…”