Aluminum-induced toxicity in Urochloa brizantha genotypes: A first glance into root Al-apoplastic and -symplastic compartmentation, Al-translocation and antioxidant performance

Autor(es)

Furlan, Felipe ^[1] ; Borgo, Lucelia ^[2] ; Silveira Rabelo, Flavio Henrique ^[2] ; Rossi, Monica Lanzoni ^[1] ; Linhares, Francisco Scaglia ^[1] ; Martinelli, Adriana Pinheiro ^[1] ; Azevedo, Ricardo Antunes ^[2] ; Lavres, Jose ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13400970 Piracicaba - Brazil

^[2] Univ Sao Paulo, Coll Agr Luiz de Queiroz, BR-13418900 Piracicaba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Chemosphere; v. 243, MAR 2020.
• Citações Web of Science: 0

Resumo

Previous studies have unraveled contrasting Al genotypic differences between Urochloa brizantha cv. Marandu (moderately tolerant) and Urochloa brizantha cv. Xaraes (more tolerant). Our objective was to evaluate differences in the response to Al-induced stress between these genotypes, focusing on Al compartmentation in the root apoplast and symplast, and antioxidant enzyme activities after Al exposure. Al-accumulation was 25% higher in the roots of cv. Xaraes than cv. Marandu, while in the shoot Al accumulation was 150% higher in cv. Marandu than cv. Xaraes. U. brizantha cv. Marandu accumulated 73% of the Al absorbed in the root symplast and 27% in the root apoplast, while cv. Xaraes accumulated 61% of the Al absorbed in symplast and 39% in apoplast. Furthermore, Al exposure leaded to physiological and developmental changes in root morphology, such as disorganization of vascular system, the collapse of cortical cells and absence of root hairs from the root tip, with more drastic effects detectable in cv. Marandu. Catalase (CAT) and guaiacol peroxidase (GPDX) activities in the roots of cv. Marandu were lower compared to cv. Xaraes. Our results pointed out that higher Al compartmentalization rates in the root apoplast, altogether with up-regulated metabolic activities of CAT and GPDX and also lower long distance transport of Al are seemingly at the base of the Al tolerance in cv. Xaraes. In conclusion, biochemical analysis of roots suggested that understanding of metabolic pathways is one of pressing approach to elucidate stress tolerance mechanisms in this genus. (C) 2019 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 13/02986-0 - Tolerância diferencial ao alumínio em plantas do gênero Brachiaria: morfologia do sistema radicular, sistema antioxidativo e alumínio trocável no apoplasto
• Beneficiário: Felipe Furlan
• Modalidade de apoio: Bolsas no Brasil - Mestrado