ANNALS OF APPLIED BIOLOGY, cilt.171, sa.2, ss.190-201, 2017 (SCI-Expanded)
This study evaluated the hypothesis that the organic chelant ethylenediamine-N,N-disuccinic acid (EDDS) mitigates plant damage under salinity, and that this is accomplished by EDDS-induced effects on cation uptake. Damaging effects of salinity on plants often involve inhibited uptake of nutritional cations, such as K and Ca, and excessive accumulation of Na. Therefore, mechanisms that improve uptake of K and Ca, or reduce Na uptake, have a potential for ameliorating salinity damages. Organic chelants increase heavy-metal cation availability at the site of uptake and increase their uptake by the roots or in planta transport. Although organic chelants are routinely used in agriculture to enhance uptake of heavy-metal cations into plants, and for soil bioremediation, their effect on uptake of cation-macronutrients is not known, and neither is their impact on plant function under salinity. In this study, we evaluated the response of strawberry plants to EDDS application (0, 1, 3 and 5 mmol kg soil(-1)), under six levels of NaCl (0, 3, 6, 9, 12 and 15 mmol L-1). EDDS application under salinity improved vegetative development, as well as reproductive growth and chlorophyll content, with statistically significant interaction between chelant dosage and level of salinity. The mitigation of salinity damage by EDDS occurred at high salinity treatments (from 9 mM NaCl). Application rates of 1-3 mmol EDDS kg(-1) were optimal for mitigating salinity effects on reproductive development, but in accordance with the extent of chelant-induced accumulation of the macronutrients K, Ca and P in the leaves, higher application rates (3-5 mmol EDDS kg(-1)) were required for optimal improvement of vegetative development. These results suggest that EDDS improves plant function under mild salinities by interfering with salinity effects on the plant ionome.