Aluminum-induced stomatal closure is related to low root hydraulic conductance and high ABA accumulation

Autor(es)

Gavassi, Marina Alves ^[1] ; Dodd, Ian Charles ^[2] ; Puertolas, Jaime ^[2] ; Silva, Giselle Schwab ^[1] ; Carvalho, Rogerio Falleiros ^[3] ; Habermann, Gustavo ^[4]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Inst Biociencias, Programa Posgrad Biol Vegetal, UNESP, Dept Biodiversidade, Av 24-A 1515, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Lancaster, Lancaster Environm Ctr, Lib Ave, Lancaster LA1 4YQ - England

^[3] Univ Estadual Paulista, Fac Ciencias Agr & Vet, Dept Biol Aplicada Agr, UNESP, Via Acesso Prof Paulo Donato Castelane Castellane, BR-14884900 Jaboticabal, SP - Brazil

^[4] Univ Estadual Paulista, Inst Biociencias, Dept Biodiversidade, UNESP, Av 24-A 1515, BR-13506900 Rio Claro, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL AND EXPERIMENTAL BOTANY; v. 179, NOV 2020.
• Citações Web of Science: 3

Resumo

Many studies ask how aluminum (Al) reduces the root growth, but as Al is mostly retained in the root system, physiological explanations for the also expected Al-induced decrease in stomatal conductance (g(s)) are unclear, mainly in well-watered conditions. We exposed tomato plants (Solarium lycopersicum) to 0, 25, 50 and 100 mu M Al in nutrient solution to investigate whether Al impairs root hydraulic conductance (Lp(r)), affecting leaf water potential (Psi(leaf)) and possibly inducing abscisic acid (ABA) accumulation in roots and/or leaves. We also measured ABA delivery rate, xylem sap pH and the root/leaf area ratio in order to explain the low g(s) in plants exposed to Al. Declines in Lp(r). and g(s) were proportional to the increase in Al concentration, and all Al treatments similarly decreased Psi(leaf), indicating the plant's attempt to reduce water loss through transpiration while accumulating more ABA. Despite Al-induced increases in root ABA, the root-to-shoot delivery of ABA did not enhance, but Al caused root xylem sap alkalization. Despite the stability of root/leaf area ratio across a range of Al concentrations (0, 25 and 50 mu M Al), the leaf hydration and stomatal opening was not conserved. Here we provide the first evidence that decreases in Lp(r). and increases in ABA might explain Al-induced stomatal closure. (AU)

• Processo FAPESP: 15/25409-4 - Papel do ABA nas relações hídricas em metabolismos contrastantes à sensibilidade ao Al3+
• Beneficiário: Marina Alves Gavassi
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 18/08902-7 - Sinalização do ABA para o fechamento estomático sob estresse por Al
• Beneficiário: Marina Alves Gavassi
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado