Guevara-Araya María José, Escobedo Víctor M, Palma-Onetto Valeria, González-Teuber Marcia
Departamento de Química Ambiental, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción 4090541, Chile.
Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3460000, Chile.
Plants (Basel). 2022 Jun 5;11(11):1511. doi: 10.3390/plants11111511.
Despite the widespread occurrence of fungal endophytes (FE) in plants inhabiting arid ecosystems, the environmental and soil factors that modulate changes in FE diversity and community composition along an aridity gradient have been little explored. We studied three locations along the coast of the Atacama Desert in Chile, in which the plant naturally grows, and that differ in their aridity gradient from hyper-arid to semi-arid. We evaluated if root-associated FE diversity (frequency, richness and diversity indexes) and community composition vary as a function of aridity. Additionally, we assessed whether edaphic factors co-varying with aridity (soil water potential, soil moisture, pH and nutrients) may structure FE communities. We expected that FE diversity would gradually increase towards the aridity gradient declines, and that those locations that had the most contrasting environments would show more dissimilar FE communities. We found that richness indexes were inversely related to aridity, although this pattern was only partially observed for FE frequency and diversity. FE community composition was dissimilar among contrasting locations, and soil water availability significantly influenced FE community composition across the gradient. The results indicate that FE diversity and community composition associated with relate to differences in the aridity level across the gradient. Overall, our findings reveal the importance of climate-related factors in shaping changes in diversity, structure and distribution of FE in desert ecosystems.
尽管真菌内生菌（FE）广泛存在于干旱生态系统中的植物体内，但调节FE多样性和群落组成沿干旱梯度变化的环境和土壤因素却鲜有研究。我们研究了智利阿塔卡马沙漠沿岸的三个地点，这些地方植物自然生长，且干旱梯度从极度干旱到半干旱各不相同。我们评估了根系相关的FE多样性（频率、丰富度和多样性指数）和群落组成是否会随着干旱程度的变化而变化。此外，我们还评估了与干旱共同变化的土壤因子（土壤水势、土壤湿度、pH值和养分）是否会构建FE群落。我们预计，随着干旱梯度的下降，FE多样性会逐渐增加，且环境差异最大的地点FE群落差异也会更大。我们发现丰富度指数与干旱呈负相关，不过这种模式在FE频率和多样性方面仅部分观察到。在不同的地点，FE群落组成不同，土壤水分有效性在整个梯度上显著影响FE群落组成。结果表明，与植物相关的FE多样性和群落组成与整个梯度上干旱水平的差异有关。总体而言，我们的研究结果揭示了气候相关因素在塑造沙漠生态系统中FE多样性、结构和分布变化方面的重要性。
