Differential aluminium-impaired nutrient uptake along the root axis of two maize genotypes contrasting in resistance to aluminium

Autor(es)

Mariano, Eduardo D. ^[1] ; Pinheiro, Aluisio S. ^[2] ; Garcia, Edivaldo E. ^[3] ; Keltjens, Willem G. ^[4] ; Jorge, Renato A. ^[5] ; Menossi, Marcelo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, UNICAMP, Dept Genet Evolut & Bioagents, Inst Biol, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Inst Math Stat & Sci Computat, UNICAMP, BR-13083970 Campinas, SP - Brazil

^[3] Univ Estadual Maringa, Dept Chem, UEM, BR-87020900 Maringa, Parana - Brazil

^[4] Wageningen Univ, Dept Soil Qual, WUR, NL-6700 AA Wageningen - Netherlands

^[5] Univ Estadual Campinas, Inst Chem, Dept Phys Chem, UNICAMP, BR-13084971 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLANT AND SOIL; v. 388, n. 1-2, p. 323-335, MAR 2015.
• Citações Web of Science: 6

Resumo

The sensitivity of root cells and root processes to toxic aluminium ions (Al3+) varies along the root axis. This study was established to assess the sensitivity of nutrient uptake to Al along the main root axis of maize genotypes that differ in resistance to Al and to test whether citrate, an Al-complexing compound that is unevenly released along the root axis, can play a role in protecting the root from Al-impaired nutrient uptake. A divided-root-chamber technique was used to measure net fluxes of calcium (Ca2+), magnesium (Mg2+), and potassium (K+) along intact roots of two maize genotypes differing in resistance to Al. The accumulation of Al along their main root axis was also measured in short-term experiments. Results of these experiments were compared with those of a previous study, where citrate exudation had been measured along identical maize root axes. Aluminium affected nutrient uptake widely along the root with strong effects in the apical region, reducing total Ca2+ and Mg2+ uptake, but not K+ uptake. The negative effects of Al3+ were more pronounced in the Al sensitive genotype than in the resistant one. The former also accumulated more Al in its roots than the latter, but this differential accumulation was observed only in the apical part of the root. The spatial pattern of nutrient uptake, irrespective of Al treatment, did not match that of Al-stimulated citrate exudation. Based on the differential sensitivity of the root axis of the two maize genotypes and especially on the extent of the root zones where these differences are expressed, it is suggested that the less Al-disturbed nutrient uptake of a genotype is associated with its resistance to Al. (AU)

• Processo FAPESP: 04/04821-0 - Avaliacao quantitativa do potencial de protecao dos acidos organicos exsudados pelas raizes contra os efeitos do aluminio toxico do solo.
• Beneficiário: Eduardo Dal'Ava Mariano
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 11/00189-0 - Alteração da acidez do apoplasto da raiz como mecanismo de resistência a alumínio em milho
• Beneficiário: Isadora de Camargo Ribeiro
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica