The LATERAL ORGAN BOUNDARIES Gene Defines a Novel, Plant-Specific Gene Family

• Published in: Plant physiology (Bethesda) 2002-06, Vol.129 (2), p.747-761
• Main Authors: Shuai, Bin, Reynaga-Peña, Cristina G., Springer, Patricia S.
• Format: Article
• Language: English
• Subjects: Alternative Splicing; Amino Acid Sequence; Amino acids; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Boundaries; Complementary DNA; Cotyledons; Development and Hormone Action; DNA Transposable Elements - genetics; DNA, Complementary - chemistry; DNA, Complementary - genetics; Environmental conditions; Flowers; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genes; Genomics; Glucuronidase - genetics; Glucuronidase - metabolism; Growth conditions; Molecular Sequence Data; Multigene Family - genetics; Mutation; Phenotype; Plant roots; Plant Roots - genetics; Plant Roots - growth & development; Plant Shoots - genetics; Plant Shoots - growth & development; Plant species; Plants; Plants, Genetically Modified; Proteins; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Reverse transcriptase polymerase chain reaction; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Stem cells
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.010926

The LATERAL ORGAN BOUNDARIES (LOB) gene in Arabidopsis defines a new conserved protein domain. LOB is expressed in a band of cells at the adaxial base of all lateral organs formed from the shoot apical meristem and at the base of lateral roots. LOB encodes a predicted protein that does not have recognizable functional motifs, but that contains a conserved domain (the LOB domain) that is present in 42 other Arabidopsis proteins and in proteins from a variety of other plant species. Proteins showing similarity to the LOB domain were not found outside of plant databases, indicating that this unique protein may play a role in plant-specific processes. Genes encoding LOB domain proteins are expressed in a variety of temporal- and tissue-specific patterns, suggesting that they may function in diverse processes. Loss-of-function LOB mutants have no detectable phenotype under standard growth conditions, suggesting that LOB is functionally redundant or required during growth under specific environmental conditions. Ectopic expression of LOB leads to alterations in the size and shape of leaves and floral organs and causes male and female sterility. The expression of LOB at the base of lateral organs suggests a potential role for LOB in lateral organ development.