Features of air masses associated with the deposition of Pseudomonas syringae and Botrytis cinerea by rain and snowfall

Abstract

Clarifying the role of precipitation in microbial dissemination is essential for elucidating the processes involved in disease emergence and spread. The ecology of Pseudomonas syringae and its presence throughout the water cycle makes it an excellent model to address this issue. In this study, 90 samples of freshly fallen rain and snow collected from 2005-2011 in France were analyzed for microbiological composition. The conditions favorable for dissemination of P. syringae by this precipitation were investigated by (i) estimating the physical properties and backward trajectories of the air masses associated with each precipitation event and by (ii) characterizing precipitation chemistry, and genetic and phenotypic structures of populations. A parallel study with the fungus Botrytis cinerea was also performed for comparison. Results showed that (i) the relationship of P. syringae to precipitation as a dissemination vector is not the same for snowfall and rainfall, whereas it is the same for B. cinerea and (ii) the occurrence of P. syringae in precipitation can be linked to electrical conductivity and pH of water, the trajectory of the air mass associated with the precipitation and certain physical conditions of the air mass (i.e. temperature, solar radiation exposure, distance traveled), whereas these predictions are different for B. cinerea. These results are pertinent to understanding microbial survival, emission sources and atmospheric processes and how they influence microbial dissemination.

Perspectives on the Future of Ice Nucleation Research: Research Needs and Unanswered Questions Identified from Two International Workshops

“…It should be noted that recent studies examined feldspar samples of which some were ice active at a high temperature range [97,98], but it remains to be seen which role these particles play in the atmosphere, since their abundance is unclear. The plant pathogenic bacterium, Pseudomonas syringae, is an important microbial ice nucleator that has been found in clouds, rain, and snow [9, [99][100][101][102][103]. A handful of fungi have also been reported to be ice nucleators, including species of Fusarium and Mortierella [104][105][106].…”

Laboratory Study of Effects of Atmospheric Pollutants on Ice Nucleation Activity of Bacteria

“…Since some kinds of bioaerosols can act as ice nuclei even at temperatures warm than -10°C (Schnell and Vali, 1972;Diehl et al, 2001;Iannone et al, 2011;Knopf et al, 2011;Morris et al, 2013;Joly et al, 2014), bioaerosols as an important component of aerosols in the atmosphere have been paid much more attentions over the past decades (Schnell and Vali, 1972;Diehl et al, 2001;Iannone et al, 2011;Knopf et al, 2011;Morris et al, 2013). Ice nucleation-active bioaerosols have widely been found in different regions and climates (Schnell and Vali, 1976;Christner et al, 2008a;Christner et al, 2008b;Pratt et al, 2009;Conen et al, 2011;Garcia et al, 2012;Burrows et al, 2013;Huffman et al, 2013;Monteil et al, 2014;O'Sullivan et al, 2014). Recent numerical studies show that ice nucleation-active bioaerosols can trigger the ice multiplication in the warmbased precipitating shallow cumulus clouds (Ariya et al, 2009;Sun et al, 2010;Sun et al, 2012).…”

Sources of organic ice nucleating particles in soils

“…Recently there has been a resurgence of related research, with the general aims of correlating abundances of organic INPs in the boundary layer with local ecotypes (Prenni et al, 2009;Bowers et al, 2010;Garcia et al, 2012;Tobo et al, 2013;Mason et al, 2015), gauging the stimulation of their release by humidity, rainfall, and harvesting (Garcia et al, 2012;Huffman et al, 2013;Prenni et al, 2013;Wright et al, 2014;Bigg et al, 2015), and measuring organic INP abundance in clouds and precipitation (Christner et al, 2008;Delort et al, 2010;Joly et al, 2014;Monteil et al, 2014;Morris et al, 2008;Petters and Wright, 2015;Šantl-Temkiv et al, 2015).…”