Atmospheric Absorption of Fluoride by Cultivated Species. Leaf Structural Changes and Plant Growth

Autor(es)

Mesquita, Geisa Lima ^[1] ; Ossamu Tanaka, Francisco Andre ^[2] ; Cantarella, Heitor ^[1] ; Mattos, Jr., Dirceu ^[3]

Afiliação do(s) autor(es)

^[1] Inst Agr, Ctr Citricultura Sylvio Moreira, BR-13012970 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Escola Super Agricultura Luiz Queiroz, BR-13418900 Sao Paulo - Brazil

^[3] Inst Agr, Ctr Citricultura Sylvio Moreira, BR-13490000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: WATER AIR AND SOIL POLLUTION; v. 219, n. 1-4, p. 143-156, JUL 2011.
• Citações Web of Science: 16

Resumo

Fluoride (F) is an air pollutant that causes phytotoxicity. Besides the importance of this, losses of agricultural crops in the vicinity of F polluting industries in Brazil have been recently reported. Injuries caused to plant leaf cell structures by excess F are not well characterized. However, this may contribute to understanding the ways in which plant physiological and biochemical processes are altered. A study evaluated the effects of the atmospheric F on leaf characteristics and growth of young trees of sweet orange and coffee exposed to low (0.04 mol L(-1)) or high (0.16 mol L(-1)) doses of HF nebulized in closed chamber for 28 days plus a control treatment not exposed. Gladiolus and ryegrass were used as bioindicators in the experiment to monitor F exposure levels. Fluoride concentration and dry mass of leaves were evaluated. Leaf anatomy was observed under light and electron microscopy. High F concentrations (similar to 180 mg kg(-1)) were found in leaves of plants exposed at the highest dose of HF. Visual symptoms of F toxicity in leaves of citrus and coffee were observed. Analyses of plant tissue provided evidence that F caused degeneration of cell wall and cytoplasm and disorganization of bundle sheath, which were more evident in Gladiolus and coffee. Minor changes were observed for sweet orange and ryegrass. Increase on individual stomatal area was also marked for the Gladiolus and coffee, and which were characterized by occurrence of opened ostioles. The increased F absorption by leaves and changes at the structural and ultrastructural level of leaf tissues correlated with reduced plant growth. (AU)

• Processo FAPESP: 08/09541-6 - Efeitos da absorção foliar do flúor atmosférico sobre o desenvolvimento, estado nutricional e metabolismo vegetal
• Beneficiário: Dirceu de Mattos Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/52557-0 - Efeitos da absorcao do fluor atmosferico sobre o desenvolvimento, estado nutricional e metabolismo vegetal.
• Beneficiário: Geisa Lima Mesquita Zambrosi
• Modalidade de apoio: Bolsas no Brasil - Mestrado