Incrocci Luca, Carmassi Giulia, Maggini Rita, Poli Caterina, Saidov Djamshed, Tamburini Chiara, Kiferle Claudia, Perata Pierdomenico, Pardossi Alberto
Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.
Samarkand Agricultural Institute, Samarkand, Uzbekistan.
Front Plant Sci. 2019 Dec 18;10:1494. doi: 10.3389/fpls.2019.01494. eCollection 2019.
Iodine deficiency is a serious world-wide public health problem, as it is responsible for mental retardation and other diseases. The use of iodine-biofortified vegetables represents a strategic alternative to iodine enriched salt for people with a low sodium diet. However, at high concentrations iodine can be toxic to plants. Therefore, research on plant iodine toxicity is fundamental for the development of appropriate biofortification protocols. In this work, we compared two cultivars of sweet basil ( L.) with different iodine tolerance: "Tigullio," less tolerant, with green leaves, and "Red Rubin," more tolerant and with purple leaves. Four greenhouse hydroponic experiments were conducted in spring and in summer with different concentrations of iodine in the nutrient solution (0.1, 10, 50, 100, and 200 μM), supplied as potassium iodide (KI) or potassium iodate (KIO). Plant growth was not affected either by 10 μM KI or by 100 μM KIO, while KI concentrations higher than 50 μM significantly reduced leaf area, total plant dry matter and plant height. The severity of symptoms increased with time depending on the cultivar and the form of iodine applied. Growth inhibition by toxic iodine concentrations was more severe in "Tigullio" than in "Red Rubin," and KI was much more phytotoxic than KIO. Leaf iodine concentration increased with the iodine concentration in the nutrient solution in both varieties, while the total antioxidant power was generally higher in the purple variety. In both basil cultivars, a strong negative correlation was found between the photosynthesis and the leaf iodine content, with significant differences between the regression lines for "Tigullio" and "Red Rubin." In conclusion, the greater tolerance to iodine of the "Red Rubin" variety was associated with the ability to withstand higher concentrations of iodine in leaf tissues, rather than to a reduced accumulation of this element in the leaves. The high phenolic content of "Red Rubin" could contribute to the iodine tolerance of this purple cultivar.
碘缺乏是一个严重的全球性公共卫生问题，因为它会导致智力发育迟缓及其他疾病。对于钠摄入较少的人群而言，食用碘生物强化蔬菜是替代碘强化盐的一种战略选择。然而，高浓度的碘对植物可能有毒性。因此，开展植物碘毒性研究对于制定合适的生物强化方案至关重要。在本研究中，我们比较了两种对碘耐受性不同的甜罗勒（L.）品种：耐受性较差、叶片为绿色的 “蒂古利奥”，以及耐受性较强、叶片为紫色的 “红鲁宾”。在春季和夏季进行了四项温室水培实验，营养液中添加不同浓度的碘（0.1、10、50、100 和 200 μM），以碘化钾（KI）或碘酸钾（KIO）的形式提供。10 μM 的 KI 或 100 μM 的 KIO 均未影响植物生长，而高于 50 μM 的 KI 浓度显著降低了叶面积、植株总干物质和株高。症状的严重程度随时间增加，这取决于品种和所施用碘的形态。有毒碘浓度对生长的抑制作用在 “蒂古利奥” 中比在 “红鲁宾” 中更严重，并且 KI 的植物毒性比 KIO 大得多。两个品种的叶片碘浓度均随营养液中碘浓度的增加而升高，而紫色品种的总抗氧化能力通常更高。在两个罗勒品种中，光合作用与叶片碘含量之间均存在强烈的负相关，“蒂古利奥” 和 “红鲁宾” 的回归线之间存在显著差异。总之，“红鲁宾” 品种对碘的耐受性更强，这与其能够耐受叶片组织中更高浓度的碘有关，而不是叶片中该元素的积累减少。“红鲁宾” 中高含量的酚类物质可能有助于该紫色品种对碘的耐受性。
