H+- and Al3+-induced responses on the wall of root cells of nine hormonal classes mutants and transgenics of tomato Micro-Tom

• Grant number: 11/09360-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2011
• End date: July 31, 2012
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Lázaro Eustaquio Pereira Peres
• Grantee: Lucia Mattiello
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

H+ and Al3+ toxicity, present in acid soils, are yield limiting factors. Studies in this area often presume independent effects of H+ and Al3+. However, both cause cell wall damages which can compromise its functionality and integrity, and, thus, mutually influence their interactions with the cell wall. Additionally, the sensibility varies with cell type, being the most sensitive to both, H+ and Al3+, cells in the elongation zone. Evidences indicate that threat perception to the wall involve RLKs (Receptor-like kinases) and the responses include hormonal signalization that activates remodeling processes on the wall, including those related to ROS, that can break or link inside and between polysaccharides chains, modulating its extensibility. Hormones probably have a central role in the H+ and Al3+ responses, however, this questions is still not address frequently. Mutants and transgenic lines from tomato Micro-Tom (MT) is an excellent tool because they are in the same genetic background. This tool allows comparisons between mutants and the production of double or triple mutants. Such approach is evident since cellular processes are, in majority of times, controlled and regulates by more of one hormonal class. The objectives of this study are: a) characterize MT responses to low pH and Al3+ examining: response curve to pH, response curve to Al3+ and response to Al3+ exposition after been exposed to low pH; b) Evaluate mutants and transgenic responses to low pH and Al3+; c) Evaluate the role of cell wall oxidative modulation in response to low pH and Al3+ of MT and its hormonal mutants and transgenics using techniques such: ROS (O2*- e H2O2) levels detection in the cell wall, use of NADPH oxidade and peroxidase inhibitors, exogenous application of anti-oxidants and determination of peroxidase activity in the cell wall.