Relationship between silica and silicophytoliths with heavy metals in a wheat (Triticum aestivum) planted with silicon fertilization

Abstract

Plants can absorb Si from the soil solution to produce biomineralizations, known as silicophytoliths (SiP), which could helpto mitigate abiotic stresses, including improved tolerance to heavy metals (HM). The Argentinian Pampean plain regionis highly fertile and intensive agricultural activities are carried out. This work evaluates the effect of Si fertilization on theHM content of soils and plants in an agricultural area cultivated with wheat (Triticum aestivum) in the southeastern regionof the Pampean plains. The HM content was analyzed in soil and plant organs with ICP-OES, while SiP content was measured by calcination; finally, SEM and EDS analyses were performed. In general, no statistically significant effect after theapplication of silicon fertilizers was detected, but an inverse relation was observed between the Si and HM contents in soiland the aboveground organs of the crop. Within the plant organs, a strong relationship between the distribution of HM andSiP contents was found and this relation could also be seen with SEM and EDS analysis done. This is the first work thataddresses, within the agroecosystems of the Pampean plains, Si and HM contents in wheat crops and provides basic datato evaluate possible studies related to their effects under different stress conditions. Although further studies at the cellularlevel are needed to elucidate some hypotheses, the results obtained suggest that it could be useful to apply Si fertilization asan environmentally friendly strategy.