Leaf ontogeny of Schinus molle L. plants under cadmium contamination: the meristematic origin of leaf structural changes.
Previous works show the development of thicker leaves on tolerant plants growing under cadmium (Cd2+) contamination. The aim of this study was to evaluate the Cd2+effects on the leaf meristems of the tolerant species Schinus molle. Plants were grown in nutrient solution containing 0, 10, and 50 μM of Cd2+. Anatomical analysis was performed on leaf primordia sampled at regular time intervals. Under the lowest Cd2+level (10 μM), increased ground meristem thickness, diameter of the cells, cell elongation rate, and leaf dry mass were found. However, 50 μM of Cd2+reduced all these variables. In addition, the ground meristem cells became larger when exposed to any Cd2+level. The epidermis, palisade parenchyma, and vascular tissues developed earlier in Cd2+-exposed leaves. The modifications found on the ground meristem may be related to the development of thicker leaves on S. molle plants exposed to low Cd2+levels. Furthermore, older leaves showed higher Cd2+content when compared to the younger ones, preventing the Cd2+toxicity to these leaves. Thus, low Cd2+concentrations change the ground meristem structure and function reflecting on the development of thicker and enhanced leaves.
Departamento de Biologia, Programa de Pós-Graduação em Botânica Aplicada, Universidade Federal de Lavras, UFLA, Lavras, Minas Gerais, 37200-000, Brazil.
Marcio Paulo
MP
Pereira
Departamento de Biologia, Programa de Pós-Graduação em Botânica Aplicada, Universidade Federal de Lavras, UFLA, Lavras, Minas Gerais, 37200-000, Brazil.
Felipe Fogaroli
FF
Corrêa
Departamento de Biologia, Programa de Pós-Graduação em Botânica Aplicada, Universidade Federal de Lavras, UFLA, Lavras, Minas Gerais, 37200-000, Brazil.
Evaristo Mauro
EM
de Castro
Departamento de Biologia, Programa de Pós-Graduação em Botânica Aplicada, Universidade Federal de Lavras, UFLA, Lavras, Minas Gerais, 37200-000, Brazil.
Jean Paulo Vitor
JPV
de Oliveira
Instituto de Ciências da Natureza, Universidade Federal de Alfenas, Unifal, Campus Alfenas, Alfenas, MG, CEP 37130-000, Brazil. fabricio.pereira@unifal-mg.edu.br.
Fabricio José
FJ
Pereira
D027926:Anacardiaceae / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology*; D018519:Meristem / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism / Q000494:pharmacology*; D013312:Stress, Physiological
D012989:Soil Pollutants; D002104:Cadmium
Cell elongation rate; Heavy metal; Leaf meristems; Leaf primordia; Pepper tree