Combined impact of short-term phosphorus deficiency and microplastic contamination on tomato mineral elements, chlorophyll fluorescence and root exudates
Alice Pita-Barbosa, Oussama Bouaicha, Raphael Tiziani, M. Chibesa, Luigimaria Borruso, Stefano Cesco, Tanja Mimmo
Abstract
) on tomato physiology. Plants were grown hydroponically under four treatments: control (+P/C), phosphorus deficiency (-P/C), MP exposure (+P/MP), and combined stress (-P/MP). After 38 days of growth (24 under -P and 14 with MP exposure) root exudates were collected over 4 h, and plants were harvested. Chlorophyll fluorescence parameters were assessed, and elemental composition of shoots and roots was analyzed via ICP-MS. Root exudates were examined for carboxylates, total organic carbon, proteins, and phenolics. Root exudation was mainly influenced by -P, with no additional effects observed under -P/MP. Ca root content increased significantly in both MP treatments (+P/MP, -P/MP). Interestingly, the -P/MP treatment reduced the -P-induced accumulation of Fe, Zn, and Mo. While + P/MP alone had no effect on chlorophyll fluorescence parameters, the combined stress (-P/MP) significantly mitigated the negative effects of -P on all photosynthetic traits. These findings highlight the importance of studying interactive effects of emerging pollutants with nutrient stresses to better predict plant responses in future environments.