Identification and quantification of phytochelatins in roots of rice to long-term exposure: evidence of individual role on arsenic accumulation and translocation

Autor(es)

Batista, Bruno Lemos ^{[1, 2]} ; Nigar, Meher ^[3] ; Mestrot, Adrien ^[4] ; Rocha, Bruno Alves ^[5] ; Barbosa Junior, Fernando ^[2] ; Price, Adam H. ^[3] ; Raab, Andrea ^[6] ; Feldmann, Joerg ^[6]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Santo Andre, SP - Brazil

^[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, BR-14049 Ribeirao Preto, SP - Brazil

^[3] Univ Aberdeen, Inst Biol & Environm Sci, Aberdeen AB24 3UU - Scotland

^[4] Univ Bern, Inst Geog, Soil Sci Grp, CH-3012 Bern - Switzerland

^[5] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ribeirao Preto, SP - Brazil

^[6] Univ Aberdeen, Dept Chem, TESLA Trace Element Speciat Lab, Aberdeen AB24 3UE - Scotland

• Tipo de documento: Artigo Científico
• Fonte: Journal of Experimental Botany; v. 65, n. 6, p. 1467-1479, APR 2014.
• Citações Web of Science: 62

Resumo

Six varieties of rice were exposed to low and high levels of arsenic in the same soil. Their individual responses of expressing phytochelatins have been correlated to inorganic arsenic uptake, transport, and accumulation in the rice grain.Rice has the predilection to take up arsenic in the form of methylated arsenic (o-As) and inorganic arsenic species (i-As). Plants defend themselves using i-As efflux systems and the production of phytochelatins (PCs) to complex i-As. Our study focused on the identification and quantification of phytochelatins by HPLC-ICP-MS/ESI-MS, relating them to the several variables linked to As exposure. GSH, 11 PCs, and AsPC complexes from the roots of six rice cultivars (Italica Carolina, Dom Sofid, 9524, Kitrana 508, YRL-1, and Lemont) exposed to low and high levels of i-As were compared with total, i-As, and o-As in roots, shoots, and grains. Only Dom Sofid, Kitrana 508, and 9524 were found to produce higher levels of PCs even when exposed to low levels of As. PCs were only correlated to i-As in the roots (r0.884, P < 0.001). However, significant negative correlations to As transfer factors (TF) rootsgrains (r 0.739, P < 0.05) and shootsgrains (r 0.541, P < 0.05), suggested that these peptides help in trapping i-As but not o-As in the roots, reducing grains i-As. Italica Carolina reduced i-As in grains after high exposure, where some specific PCs had a special role in this reduction. In Lemont, exposure to elevated levels of i-As did not result in higher i-As levels in the grains and there were no significant increases in PCs or thiols. Finally, the high production of PCs in Kitrana 508 and Dom Sofid in response to high As treatment did not relate to a reduction of i-As in grains, suggesting that other mechanisms such as AsPC release and transport seems to be important in determining grain As in these cultivars. (AU)

• Processo FAPESP: 10/07566-1 - Desenvolvimento de métodos rápidos de preparo de amostras para especiação química de arsênio em alimentos por LC-ICP-MS e avaliação das concentrações e do metabolismo em arroz
• Beneficiário: Bruno Lemos Batista
• Modalidade de apoio: Bolsas no Brasil - Doutorado