文档介绍：The Arabidopsis 26S Proteasome Subunit RPN1a is Required
for Optimal Plant Growth and Stress Responses
Songhu Wang , Jasmina Kurepa and Jan A. Smalle ∗
Plant Physiology, Biochemistry, Molecular Biology Program, Department of Plant and Soil Sciences, College of Agriculture, University of
Kentucky, Lexington, KY 40546, USA
munication
The current literature offers contradictory results In Arabidopsis, the RPN1 subunit is encoded by the more
regarding the role of the proteasome subunit RPN1a in highly expressed RPN1a gene (At2g20580) and the lower but
Arabidopsis development. Here we show that plants ubiquitously expressed RPN1b gene (At4g28470) ( Yang et al.
lacking RPN1a are viable and have increased cell sizes, 2004 ). The role of the RPN1a isoform in plant development Downloaded from
decreased heat shock tolerance, increased oxidative stress has been reported, but these studies yielded contradictory
tolerance and other phenotypes characteristic for 26S results (Brukhin et al. 2005, Huang et al. 2006). In one study,
proteasome subunit mutants. These results strengthen RPN1a has been shown to be essential for embryogenesis
our contention that most of the phenotypes of 26S ( Brukhin et al. 2005 ), while in another, a homozygous rpn1a
proteasome mutants in Arabidopsis described to date allele has been obtained and used to determine that 26SP- http://pcp