PT  - JOURNAL ARTICLE
AU  - Capucine Baubin
AU  - Noya Ran
AU  - Hagar Siebner
AU  - Osnat Gillor
TI  - The response of desert biocrust bacterial communities to hydration-desiccation cycles
AID  - 10.1101/2021.04.04.438350
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.04.04.438350
4099  - http://biorxiv.org/content/early/2021/04/04/2021.04.04.438350.short
4100  - http://biorxiv.org/content/early/2021/04/04/2021.04.04.438350.full
AB  - Rain events in arid environments are highly unpredictable, interspersing extended periods of drought. Therefore, following changes in desert soil bacterial communities during hydration-desiccation cycles in the field, was seldom attempted. Here, we assessed rain-mediated dynamics of active community in the Negev Desert biological soil crust (biocrust), and evaluated the changes in bacterial composition, potential function, and photosynthetic activity. We predicted that increased biocrust moisture would resuscitate the phototrophs, while desiccation would inhibit their activity. Our results show that hydration increased chlorophyll content, resuscitated the biocrust Cyanobacteria, and induced potential phototrophic functions. However, decrease in the soil water content did not immediately decrease the phototrophs activity, though chlorophyll levels decreased. Moreover, while the Cyanobacteria relative abundance significantly increased, Actinobacteria, the former dominant taxa, significantly decreased in abundance. We propose that, following a rain event biocrust moisture significantly decreased, almost to drought levels, yet the response of the active bacterial community lagged, in contrast to topsoil. Possible explanations to the described rain-mediated bacteria dynamics are discussed.Competing Interest StatementThe authors have declared no competing interest.