Do aluminum (Al)-hyperaccumulator and phosphorus (P)-solubilising species assist neighbouring plants sensitive to Al toxicity and P deficiency?

Abstract

We aimed to evaluate the facilitation effects of an aluminum (Al) hyperaccumulator species bearing cluster roots, <i>Gevuina avellana</i>, on the seedling growth and performance of an Al-intolerant and phosphorus (P)-deficient-sensitive plant, <i>Vaccinium corymbosum</i>. For this, seedlings of <i>G. avellana</i> and <i>V. corymbosum</i> were grown alone or together as follows: i) two <i>G. avellana</i> seedlings, ii) one <i>G. avellana</i> + one <i>V. corymbosum</i> and iii) two <i>V. corymbosum</i>, in soil supplemented with Al (as Al₂(SO₄)₃) and in the control (without Al supplementation). We determined relative growth rate (RGR), photosynthetic rate, chlorophyll concentration, lipid peroxidation and Al and nutrient concentration [Nitrogen (N), P, potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and sulfur (S)] in leaves and roots of both species. The results showed that, in general, <i>G. avellana</i> did not assist <i>V. corymbosum</i> to enhance its RGR nor reduce its Al uptake. However, <i>G. avellana</i> assisted <i>V. corymbosum</i> in enhanced N acquisition and, consequently, to increase its chlorophyll concentration and photosynthetic rate. Besides, <i>V. corymbosum</i> had lower lipid peroxidation in leaves when grown in the soil with high Al supplementation in association with <i>G. avellana.</i> Our results suggest a facilitating effect of <i>G. avellana</i> to <i>V. corymbosum</i> when grown in soils with high Al concentration, by enhancing chlorophyll concentrations and photosynthetic rate, and decreasing the oxidative damage to lipids.