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Effect of cadmium contamination on the rhizosphere bacterial diversity of Echinocactus platyacanthus

2020; Elsevier BV; Volume: 13; Linguagem: Inglês

10.1016/j.rhisph.2020.100187

2452-2198

Margarita María Sarria Carabalí, Felipe García‐Oliva, Luis Enrique Cortés Páez, Nguyen E. López-Lozano,

Plant Stress Responses and Tolerance

To better understand the mechanism of tolerance to heavy metals, it is relevant to analyze the effects of Cd contamination on the rhizospheric microbiota of plants with high tolerance to environmental stress such as cacti species. In this work, the effects of soil contamination with Cd on bacterial diversity, microbial carbon, abundance of diazotrophs in the soil, and on the photosynthetic efficiency and absorption of Cd of the candy barrel cactus (Echinocactus platyacanthus) were evaluated. Experimental pots sown with E. platyacanthus were contaminated with different concentrations of Cd+2. Changes in rhizospheric soil community were evaluated after 30 days of contamination. In general, soil contamination with Cd significantly changes the structure of the rizospheric bacterial community which could have serious effects on the functioning of this community, especially in N mobilization. Despite the plant not showing signs of physiological stress reflected in the photosynthetic yield, revealing its high resistance to contamination with Cd, a slight increase in the electron transport rate at low Cd concentration was observed. This increase correlates with an increase in abundance of diazotrophs and microbial C, suggesting an interesting response by the entire system to the presence of low Cd concentration in the soil. In this work, we have demonstrated that the factors analyzed here can be indicators of the quality and health of the soil, being a complement to explaining the behavior of metals in the soil matrix, and thus be able to understand the mechanism of tolerance to Cd contamination in soil.