Anatomical and physiological characteristics of leaves from Eugenia dysenterica DC. can predict nutritional deficiency symptoms

Plants receiving insufficient concentrations of the different essential nutrients may respond symptomatically to this stress. However, when the first visible symptoms of nutritional deficiency appear, plants already exhibit significant changes in their structure. As seedlings of E. dysenterica are important for the recovery of degraded areas and as the fruits of this species are widely exploited commercially, we decided to evaluate whether the omission of nutrients may affect the leaf anatomical ultrastructure, dry matter production and the synthesis of photosynthetic pigments in this plant, in an attempt to use data of this nature to predict symptoms of nutritional deficiency in seedlings of this species. For this purpose, we grow seedlings in a hydroponic system, offering all nutrients and also omitting each nutrient individually. Thus, we evaluated the effect of the omission of each nutrient on the anatomical leaf structure, dry mass production and the synthesis of photosynthetic pigments. Seedlings that grew in the absence of Ca and Mn exhibited compromised spongy parenchyma and mesophyll development, while the omission of K and Mg increased the number of epidermal cells and stomata. Low dry mass production in E. dysenterica was related to the omission of S and Mn, while P, N and Fe deficiencies directly affected the synthesis of pigments. Thus, leaf anatomical and physiological data can predict nutritional deficiency conditions, enabling the user to diagnose the deficiency before the onset of symptoms in E. dysenterica seedlings. Our results may help investigators to understand the effects of nutritional omissions on other native Cerrado plants