Selenium does not ease growth inhibition caused by aluminum in Schinus terebinthifolius seedlings

Aluminum (Al) toxicity is observed in several crops in the world and affects the yield of many cultures. Using beneficial elements such as selenium (Se) has been the object of studies focused on finding an alternative to mitigate the toxic effects of metals on crops. Thus, the aims of the current study were to assess the tolerance/sensitivity to Al, and Se mitigating effects on morphological, photosynthetic and biochemical variables recorded for Schinus terebinthifolius seedlings exposed to Al. Schinus terebinthifolius seedlings in hydroponics were subjected to the following Al and Se combinations added to the nutrient solution in mM: 0 Al + 0 Se; 0 Al + 0.0025 Se; 1.85 Al + 0 Se; 1.85 Al + 0.0025 Se; 3.71 Al + 0 Se and 3.71 Al + 2.5 Se. The study followed the completely randomized experimental design, with three repetitions. Al reduced the leaf area, shoot and root dry mass, root increment, as well as root length, surface area, volume and diameter. Seedlings' photosynthetic activity decreased possibly due to the presence of Al in them; and even when Se was present, it was not able to mitigate the effects of Al. The enzymatic and non-enzymatic antioxidant system was not able to avoid the oxidative stress caused by the presence of Al, as well as the Se was not able to minimize the effects from different Al concentrations on S. terebinthifolius seedlings. Therefore, species S. terebinthifolius is sensitive to Al in hydroponic systems and Se addition, in general, did not mitigate the toxic effects from different Al concentrations.

Automated summary

Aluminum (Al) toxicity affects the yield of many crops worldwide. The use of selenium (Se) as a beneficial element to mitigate the toxic effects of metals on crops has been studied. This study evaluated the tolerance/sensitivity to Al and the mitigating effects of Se on Schinus terebinthifolius seedlings. The results showed that Al reduced leaf area, shoot and root dry mass, root increment, as well as root length, surface area, volume, and diameter. Se was unable to mitigate the toxic effects of Al on the seedlings' photosynthetic and antioxidant systems.