Functional analysis of leafy AtRALFs peptides and affinity purification in planta of proteins that interact with AtRALF1

Author(s)

Bianca Ribeiro

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2014-04-14

Examining board members

Daniel Scherer de Moura; Maria Helena de Souza Goldman; Fabio Tebaldi Silveira Nogueira

• Advisor: Daniel Scherer de Moura

Abstract

Peptides signals are molecules involved with growth, development and defense in plants. RALF (Rapid Alkalinization Factor) is an ubiquous peptide in plant kingdom and it is involved with cell expansion. RALF peptides are organized in a multigenic family with 37 members, some are tissue-specific expressed, others are expressed in whole plant. This work is part of a larger project that has the approach to clarify the RALF peptides functions in plants and to determine its mechanism of action. This work has two distinct approaches. The first specific approach was to characterize the isoforms AtRALF19, AtRALF23, AtRALF31, AtRALF33 and AtRALF34 using mutant plants, overexpression plants and promoters analysis. The second specific approach was to identify proteins that interact with AtRALF1 peptide using in planta tandem affinity purification (TAP). The phenotype analysis of transgenic plants showed that the overexpression of the gene which codifies AtRALF33 plants presented a semi-dwarf phenotype, smaller leaf cells area and number of lobes. The mutant plants atralf33 and atralf23 presented larger stalks and leaf cells. The mutant plants atralf34 did not show significant differences when compared to wild-type plants. The promoter analysis of AtRALF34 showed a specific expression in stomata, hypocotyls and root shoot. Regarding the TAP, mcca mutant plants were transformed with the construction 35S:AtRALF1:HPB. (AU)

• FAPESP's process: 12/21872-3 - Functional analysis of AtRALF31, 33 and 34 peptides and search for interacting proteins using the affinity purification in planta
• Grantee: Bianca Ribeiro
• Support Opportunities: Scholarships in Brazil - Master