Low root PIP1-1 and PIP2 aquaporins expression could be related to reduced hydration in 'Rangpur' lime plants exposed to aluminium

Author(s)

Cavalheiro, Mariana F. ; Gavassi, Marina A. ; Silva, Giselle S. ; Nogueira, Matheus A. ; Silva, Carolina M. S. ; Domingues, Douglas S. ; Habermann, Gustavo

• Document type: Journal article
• Source: FUNCTIONAL PLANT BIOLOGY; v. 47, n. 2, p. 10-pg., 2020-01-01.

Abstract

In acidic soils, aluminium (Al) occurs as Al3+, which is phytotoxic. One of the most conspicuous symptoms of Al toxicity is the root growth inhibition, which can lead to low water uptake and consequent reduction in leaf hydration and gas exchange. However, fibrous xylem vessels have been observed in roots of 'Rangpur' lime plants (Citrus limonia L.) when exposed to Al, which could affect the functioning of aquaporins, ultimately reducing their expression. We confirmed a decrease of CO2 assimilation (A), stomatal conductance (g(s)), transpiration (E) and relative leaf water content (RWC) in 3-month-old C. limonia plants exposed to 1480 mu M Al in nutrient solution for 90 days. The estimated hydraulic conductivity from soil to the leaf (K-L) and leaf water potential (psi w) also showed low values, although not consistently reduced over time of Al exposure. The relative expression of aquaporin genes belonging to PIP family (PIP1-1, PIP1-2 and PIP2) showed downregulation for ClPIP1-1 and ClPIP2 and upregulation for ClPIP1-2 in plants exposed to Al. Furthermore, ClPIP1-1 was positively correlated with A and g(s) in plants exposed to Al. Therefore, downregulation of ClPIP1-1 and ClPIP2 in roots of 'Rangpur' lime plants could be associated with the low leaf hydration of this species when exposed to Al. (AU)

• FAPESP's process: 16/10896-0 - Can hexanoic acid signaling modulate the transcriptome, metabolome and pathogen development in coffee trees?
• Grantee: Douglas Silva Domingues
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 13/11370-3 - Gene expression on Al3+ tolerance mechanisms comparing a Cerrado species (Qualea grandiflora) and lime (Citrus limonia cv. 'Cravo')
• Grantee: Carolina de Marchi Santiago da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/26144-0 - Hydraulic, metabolic and molecular aspects of Al3+ interference in above ground plant hydration in Citrus limonia
• Grantee: Gustavo Habermann
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/25409-4 - Role of ABA in water relations in metabolisms with contrasting sensitivities to Al3+
• Grantee: Marina Alves Gavassi
• Support Opportunities: Scholarships in Brazil - Doctorate