Abstract

In Chile, the spatial and temporary variability of precipitations contribute to the phenomenon of the Atacama Flowering Desert, during which plants as holobionts quickly respond to the presence of water. However, little is known on how environment and resource pulses modulate the rhizosphere associated microbial community. Here microbial abundance, community structure and diversity of the rhizosphere associated to Cistanthe longiscapa, a characteristic element during desert bloom, were examined over a N-S precipitation gradient and between a dry and rainy year, by using high‐throughput sequencing. Along the gradient, the soil type has a stronger influence on the microbial community than the host plant. The abundance and diversity of the fungal community increase southwards, together with annual rainfall. Interestingly, in Quebrada Seca, the northernmost gradient site, no specific root associated fungi community was detected. Changes in the bacterial community correlate with site-dependent soil characteristics and not with the precipitation gradient. On the other hand, diversity of the microbial rhizosphere community in a rainy year diminishes significantly compared to bulk soil, while its specificity increases. A preliminary core microbiome was identified, containing 5 bacterial genera, p.ej. Phyllobacterium and Nocardiopsis, reported to produce effective antifungal substances against plant pathogens. Further studies will address ecological functionality of rhizosphere microbial community and how community structure could influence plants performance during the Atacama Flowering Desert phenomenon.