Partners to survive: Hoffmannseggia doellii root‐associated microbiome at the Atacama Desert

Abstract

Summary The discovery and characterization of plant species adapted to extreme environmental conditions have become increasingly important. Hoffmannseggia doellii is a perennial herb endemic to the Chilean Atacama Desert that grows in the western Andes between 2800 and 3600 m above sea level. Its growing habitat is characterized by high radiation and low water and nutrient availability. Under these conditions, H. doellii can grow, reproduce, and develop an edible tuberous root. We characterized the H. doellii soil‐associated microbiomes to understand the biotic factors that could influence their surprising ability to survive. We found an increased number of observed species and higher phylogenetic diversity of bacteria and fungi on H. doellii root soils compared with bare soil (BS) along different sites and to soil microbiomes of other plant species. Also, the H. doellii‐associated microbiome had a higher incidence of overall positive interactions and fungal within‐kingdom interactions than their corresponding BS network. These findings suggest a microbial diversity soil modulation mechanism that may be a characteristic of highly tolerant plants to diverse and extreme environments. Furthermore, since H. doellii is related to important cultivated crops, our results create an opportunity for future studies on climate change adaptation of crop plants.

Testing the stress gradient hypothesis in soil bacterial communities associated with vegetation belts in the Andean Atacama Desert

“…Previous studies on the soil microbiota along this altitudinal gradient have shown that soil fertility is associated with both plant cover and microbial diversity [ 34 , 36 , 60 ]. In addition, plant soil-associated microbiota from the TLT have been characterized to understand the biotic factors that could influence their ability to survive in this harsh environment [ 25 , 26 ]. Knowing that plant‒microbe interactions involve mechanisms by which microbes act beneficially in promoting plant growth, such as nitrogen fixation, protection against pathogens and drought resistance, among others [ 25 , 26 , 35 ], the above works suggest that a modulation of soil microbial diversity may be a characteristic of plants that are highly tolerant to diverse and extreme environments.…”

“…Thus, at each vegetation belt, seven plant species were sampled to obtain 21 soil samples. For each plant species, the root system was gently shaken to obtain the RSS fraction (~ 100 g, [ 26 ]). BS samples (100 g) were collected in triplicate at 10 cm depth from the ground and at least 1 m away from each sampled plant to obtain 21 soil samples per vegetation belt.…”

“…A recent study revealed that biological processes enriched among the top-expressed genes of dominant Atacama plant species were related to the stress response (including response to ROS, salt tolerance, DNA reparation, and heat and cold acclimation) and energy production (photosynthesis and cytokine response), among others [ 25 ]. In the case of Hoffmannseggia doellii , a perennial herb endemic to the Atacama Desert, the recruitment of bacteria with plant beneficial traits to the rhizosphere surrounding soil, including nitrogen fixation, has been reported [ 26 ], suggesting that H. doellii -associated microbiota might be essential for plant growth in zones of low nutrient availability and extreme environmental conditions. On the other hand, quinoa plants, which are known to be well adapted to stressful conditions [ 27 ], also depend on their associated microbiota for protection and growth promotion [ 28 , 29 ].…”

Relieving your stress: PGPB associated with Andean xerophytic plants are most abundant and active on the most extreme slopes

“…In contrast, the abundance and activity of PGPBs in natural systems have been scarcely explored, despite its great potential and novelty ( Pérez-Jaramillo et al, 2018 ; Leontidou et al, 2020 ). For example, PGPBs associated to wild (or native plants) species have been reported in harsh environments, such as desert ( Fuentes et al, 2020 ; Maldonado et al, 2022 ), alpine ( Sezen et al, 2016 ; Adamczyk et al, 2019 ; Wang et al, 2020 ), and saline environments ( Rueda-Puente et al, 2019 ). Additionally, some studies have explored the presence of PGPBs adapted to environments with extreme conditions, such as salinity, (e.g., PGPBs studied from the soils of Lonar Lake in India, Hingole and Pathak, 2016 ), drought (e.g., PGPBs from different desert regions of Egypt, Ashry et al, 2022 ), or low temperatures (e.g., isolated PGPBs from the Himalayas, Yadav et al, 2015 ).…”

Impact of global change on the plant microbiome

“…2101(King et al, -2110; (2) use of habitat-adapted microbiomes to promote host tolerance to warming (Carrell et al, 2022(Carrell et al, , in this issue pp. 2111(Carrell et al, -2125; and (3) utilization of microbes from extreme desert environments (Maldonado et al, 2022(Maldonado et al, , in this issue pp. 2126(Maldonado et al, -2139.…”