An ARABIDOPSIS CLASS III Peroxidase, AT2G34060, is expressed in protoxylem of one to eight day old seedlings and involved in restriction of root length
Year: 2012
Type: dissertation
Abstract: Hydrophobic polymer lignin provides water proofing and structural integrity \nto cell wall which help plants adapt to terrestrial environment. Secretory peroxidases \nare thought to generate monolignol radicals that polymerize to form lignin. In Arabidopsis \nthaliana there are 73 secretory peroxidases .Identification of tissue, cellular, and \nsubcellular location for individual peroxidases can help assigning their function. All \nsecretory peroxidases contain signal peptide for entry into endomembrane system. \nSome peroxidases have hydrophobic carboxy-termini targeting to them to vacuole. Peroxidases \nlacking hydrophobic carboxy-terminal are targeted to wall. We tagged A. \nthaliana secretory peroxidase, AT2G34060, with yellow fluorescent protein. Plants \ntransformed with this construct expressed AT2G34060 in the protoxylem cells of the roots of one to eight day old seedlings. AT2G34060 has a hydrophobic Carboxyterminal \nand aminotransferase domain. This peroxidase is located in vesicles arranged \nin a helical fluorescent pattern similar to microtubule pattern. Overexpression of \nAT2G34060 reduced the root length. A vesicular location and reduction in growth by \noverexpression suggests that AT2G43060 supports lignification by producing monolignol \nprecursors through its putative aminotransferase ability. AT2G34060 may also be \ninvolved in deglycosylation of monolignols during their vesicular transport to the wall. \nThe availability of monolignols may be a limiting factor in the lignification process. \nTherefore, a higher number of available monolignols may lead to shorter roots through \nhigher lignification. Our work identifies a peroxidase that appears in cells undergoing \nlignifications and its subcellular location in vesicles is consistent with formation of lignin. \nAlso, root shorting through overexpression is consistent with role in lignification.
Author: Mandeep Grewal
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W571715942