Evolutionary Developmental Biology (Evo-Devo)
Puhr, Rosemary , Malcomber, Simon .
Evolution of the flavin monooxygenase/YUCCA SPARSE INFLORESENCE1 lineage in grasses.
The YUCCA gene family catalyzes a broadly conserved pathway for production of the growth hormone indole acetic acid (IAA), the predominant form of auxin in plants. YUCCA genes function in the tryptophan-dependent pathway where they catalyze the conversion of tryptamine (TAM) intermediate to N-hydroxyl TAM. YUCCA genes are functionally redundant in Arabidopsis but have non-redundant roles in grasses and petunia. One YUCCA gene in maize, SPARSE INFLORESCENCE1 (SPI1), has a non-redundant role during reproductive development, but no inflorescence phenotype is reported in RNAi knockdowns of the SPI1 ortholog in rice (OsYUC1). These data suggest SPI1 function and the extent of YUCCA gene redundancy may have changed during the diversification of the grass family. Phylogenetic and comparative genomic analyses show that SPI1 orthologs are restricted to monocots and reside in syntenic chromosomal regions within grasses. RT-PCR expression analyses indicate SPI1 and orthologs are expressed broadly throughout various organs within the plant, though to varying degrees and in a stage-dependent manner. In situ hybridization analyses in diverse grasses demonstrate that SPI1 genes have largely overlapping, localized expression patterns that coincide with sites of local auxin biosynthesis associated with lateral branching. These data suggest that the apparent SPI1 functional diversification is not explained by differing expression patterns and that gene knockdown studies are needed to further characterize the evolution of SPI1 in grasses.
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1 - California State Univ. - Long Beach, Biological Sciences, 1250 Bellflower Blvd, Long Beach, CA, 90840, USA
2 - CSU - Long Beach, 1250 Bellflower Blvd, Long Beach, CA, 90840, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 8:45 AM