Plant ecological genomics at the limits of life in the Atacama Desert

Eshel, Gil; Araus, Viviana; UNDURRAGA-OSSA, SOLEDAD FRANCISCA; Soto, Daniela C.; Moraga, Carol; Miranda Montecinos, Alejandro; Moyano, Tomas; Maldonado, Jonathan; iaz, Francisca P.; Varala, Kranthi; Nelson, Chase W.; Contreras-Lopez, Orlando; Pal-Gabor, Henrietta; Kraiser, Tatiana; Carrasco-Puga, Gabriela; et. al.

Abstract

The Atacama Desert in Chile-hyperarid and with high-ultraviolet irradiance levels-is one of the harshest environments on Earth. Yet, dozens of species grow there, including Atacama-endemic plants. Herein, we establish the Talabre-Leji = a transect (TLT) in the Atacama as an unparalleled natural laboratory to study plant adaptation to extreme environmental conditions. We characterized climate, soil, plant, and soil-microbe diversity at 22 sites (every 100 m of altitude) along the TLT over a 10-y period. We quantified drought, nutrient deficiencies, large diurnal temperature oscillations, and pH gradients that define three distinct vegetational belts along the altitudinal cline. We deep-sequenced transcriptomes of 32 dominant plant species spanning the major plant clades, and assessed soil microbes by metabarcoding sequencing. The top-expressed genes in the 32 Atacama species are enriched in stress responses, metabolism, and energy production. Moreover, their root-associated soils are enriched in growthpromoting bacteria, including nitrogen fixers. To identify genes associated with plant adaptation to harsh environments, we compared 32 Atacama species with the 32 closest sequenced species, comprising 70 taxa and 1,686,950 proteins. To perform phylogenomic reconstruction, we concatenated 15,972 ortholog groups into a supermatrix of 8,599,764 amino acids. Using two codonbased methods, we identified 265 candidate positively selected genes (PSGs) in the Atacama plants, 64% of which are located in Pfam domains, supporting their functional relevance. For 59/184 PSGs with an Arabidopsis ortholog, we uncovered functional evidence linking them to plant resilience. As some Atacama plants are closely related to staple crops, these candidate PSGs are a "genetic goldmine" to engineer crop resilience to face climate change.

Más información

Título según WOS: Plant ecological genomics at the limits of life in the Atacama Desert
Título según SCOPUS: ID SCOPUS_ID:85119416947 Not found in local SCOPUS DB
Título de la Revista: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volumen: 118
Editorial: NATL ACAD SCIENCES
Fecha de publicación: 2021
DOI:

10.1073/PNAS.210117711811OF11

Notas: ISI, SCOPUS