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Phillips KA, Skirpan AL, Liu X, Christensen A, Slewinski TL, Hudson C, Barazesh S, Cohen JD, Malcomber S, McSteen P. vanishing tassel2 encodes a grass-specific tryptophan aminotransferase required for vegetative and reproductive development in maize. Plant Cell 2011; 23:550-66. [PMID: 21335375 PMCID: PMC3077783 DOI: 10.1105/tpc.110.075267] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 01/04/2011] [Accepted: 01/27/2011] [Indexed: 05/18/2023]
Abstract
Auxin plays a fundamental role in organogenesis in plants. Multiple pathways for auxin biosynthesis have been proposed, but none of the predicted pathways are completely understood. Here, we report the positional cloning and characterization of the vanishing tassel2 (vt2) gene of maize (Zea mays). Phylogenetic analyses indicate that vt2 is a co-ortholog of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 (TAA1), which converts Trp to indole-3-pyruvic acid in one of four hypothesized Trp-dependent auxin biosynthesis pathways. Unlike single mutations in TAA1, which cause subtle morphological phenotypes in Arabidopsis thaliana, vt2 mutants have dramatic effects on vegetative and reproductive development. vt2 mutants share many similarities with sparse inflorescence1 (spi1) mutants in maize. spi1 is proposed to encode an enzyme in the tryptamine pathway for Trp-dependent auxin biosynthesis, although this biochemical activity has recently been questioned. Surprisingly, spi1 vt2 double mutants had only a slightly more severe phenotype than vt2 single mutants. Furthermore, both spi1 and vt2 single mutants exhibited a reduction in free auxin levels, but the spi1 vt2 double mutants did not have a further reduction compared with vt2 single mutants. Therefore, both spi1 and vt2 function in auxin biosynthesis in maize, possibly in the same pathway rather than independently as previously proposed.
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Affiliation(s)
- Kimberly A. Phillips
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
| | - Andrea L. Skirpan
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
| | - Xing Liu
- Department of Horticultural Science and the Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, Minnesota 55108
| | - Ashley Christensen
- Department of Biological Sciences, California State University, Long Beach, California 90840
| | - Thomas L. Slewinski
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
| | - Christopher Hudson
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
| | - Solmaz Barazesh
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
| | - Jerry D. Cohen
- Department of Horticultural Science and the Microbial and Plant Genomics Institute, University of Minnesota, Saint Paul, Minnesota 55108
| | - Simon Malcomber
- Department of Biological Sciences, California State University, Long Beach, California 90840
| | - Paula McSteen
- Department of Biology, Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802
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Phillips KA, Skirpan AL, Kaplinsky NJ, McSteen P. Developmental disaster1: A novel mutation causing defects during vegetative and inflorescence development in maize (Zea mays, Poaceae). Am J Bot 2009; 96:420-430. [PMID: 21628197 DOI: 10.3732/ajb.0800268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Axillary meristems, which give rise to branches and flowers, play a critical role in plant architecture and reproduction. To understand how axillary meristems initiate, we have screened for mutants with defects in axillary meristem initiation to uncover the genes controlling this process. These mutants, called the barren class of mutants in maize (Zea mays), have defects in axillary meristem initiation during both vegetative and reproductive development. Here, we identify and characterize a new member of the barren class of mutants named Developmental disaster1 (Dvd1), due to the pleiotropic effects of the mutation. Similar to the barren mutants, Dvd1 mutants have fewer branches, spikelets, florets, and floral organs in the inflorescence due to defects in the initiation of axillary meristems. Furthermore, double mutant analysis with teosinte branched1 shows that dvd1 also functions in axillary meristems during vegetative development. However, unlike the barren mutants, Dvd1 mutants are semidwarf due to the production of shorter internodes, and they produce leaves in the inflorescence due to the outgrowth of bract leaf primordia. The suite of defects seen in Dvd1 mutants, together with the genetic interaction of Dvd1 with barren inflorescence2, suggests that dvd1 is a novel regulator of axillary meristem and internode development.
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Affiliation(s)
- Kimberly A Phillips
- Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, Pennsylvania 16802 USA
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Skirpan AL, Dowd PE, Sijacic P, Jaworski CJ, Gilroy S, Kao TH. Identification and characterization of PiORP1, a Petunia oxysterol-binding-protein related protein involved in receptor-kinase mediated signaling in pollen, and analysis of the ORP gene family in Arabidopsis. Plant Mol Biol 2006; 61:553-65. [PMID: 16897474 DOI: 10.1007/s11103-006-0030-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2005] [Accepted: 02/20/2006] [Indexed: 05/11/2023]
Abstract
Oxysterol-binding proteins (OSBPs) and oxysterol-binding-protein related proteins (ORPs) are encoded by most eukaryotic genomes examined to date; however, they have not yet been characterized in plants. Here we report the identification and characterization of PiORP1, an ORP of Petunia inflata that interacts with the cytoplasmic kinase domain of a receptor-like kinase, named PRK1, of P. inflata. PiORP1 is phosphorylated by PRK1 in vitro and therefore may be involved in PRK1 signaling during pollen development and growth. RNA gel blot analysis showed that PiORP1 and PRK1 had very similar expression patterns in developing pollen, mature pollen and pollen tubes. GFP fusion proteins of PiORP1 localized in the plasma membrane of pollen tubes at distinct foci and its PH domain alone was sufficient to mediate this localization. The sequence for the oxysterol-binding domain of PiORP1 was used to search the genome of Arabidopsis; 12 ORPs were identified and phylogenetic analysis revealed that they fell into two distinct clades, consistent with the ORPs of other eukaryotes. RT-PCR analysis showed that all 12 Arabidopsis ORPs were expressed; 10 were expressed in most of the tissues examined under normal growth conditions, but only three were expressed in pollen.
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Affiliation(s)
- Andrea L Skirpan
- Department of Biochemistry and Molecular Biology, 403 Althouse Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
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Dowd PE, Coursol S, Skirpan AL, Kao TH, Gilroy S. Petunia phospholipase c1 is involved in pollen tube growth. Plant Cell 2006. [PMID: 16648366 DOI: 10.1105/tpc.106.041582.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Although pollen tube growth is essential for plant fertilization and reproductive success, the regulators of the actin-related growth machinery and the cytosolic Ca2+ gradient thought to determine how these cells elongate remain poorly defined. Phospholipases, their substrates, and their phospholipid turnover products have been proposed as such regulators; however, the relevant phospholipase(s) have not been characterized. Therefore, we cloned cDNA for a pollen-expressed phosphatidylinositol 4,5-bisphosphate (PtdInsP2)-cleaving phospholipase C (PLC) from Petunia inflata, named Pet PLC1. Expressing a catalytically inactive form of Pet PLC1 in pollen tubes caused expansion of the apical Ca2+ gradient, disruption of the organization of the actin cytoskeleton, and delocalization of growth at the tube tip. These phenotypes were suppressed by depolymerizing actin with low concentrations of latrunculin B, suggesting that a critical site of action of Pet PLC1 is in regulating actin structure at the growing tip. A green fluorescent protein (GFP) fusion to Pet PLC1 caused enrichment in regions of the apical plasma membrane not undergoing rapid expansion, whereas a GFP fusion to the PtdInsP2 binding domain of mammalian PLC delta1 caused enrichment in apical regions depleted in PLC. Thus, Pet PLC1 appears to be involved in the machinery that restricts growth to the very apex of the elongating pollen tube, likely through its regulatory action on PtdInsP2 distribution within the cell.
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Affiliation(s)
- Peter E Dowd
- Department of Biochemistry and Molecular Biology, Pensylvania State University, University Park, Pensylvania 16802, USA
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Dowd PE, Coursol S, Skirpan AL, Kao TH, Gilroy S. Petunia phospholipase c1 is involved in pollen tube growth. Plant Cell 2006; 18:1438-53. [PMID: 16648366 PMCID: PMC1475500 DOI: 10.1105/tpc.106.041582] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/17/2006] [Accepted: 04/05/2006] [Indexed: 05/08/2023]
Abstract
Although pollen tube growth is essential for plant fertilization and reproductive success, the regulators of the actin-related growth machinery and the cytosolic Ca2+ gradient thought to determine how these cells elongate remain poorly defined. Phospholipases, their substrates, and their phospholipid turnover products have been proposed as such regulators; however, the relevant phospholipase(s) have not been characterized. Therefore, we cloned cDNA for a pollen-expressed phosphatidylinositol 4,5-bisphosphate (PtdInsP2)-cleaving phospholipase C (PLC) from Petunia inflata, named Pet PLC1. Expressing a catalytically inactive form of Pet PLC1 in pollen tubes caused expansion of the apical Ca2+ gradient, disruption of the organization of the actin cytoskeleton, and delocalization of growth at the tube tip. These phenotypes were suppressed by depolymerizing actin with low concentrations of latrunculin B, suggesting that a critical site of action of Pet PLC1 is in regulating actin structure at the growing tip. A green fluorescent protein (GFP) fusion to Pet PLC1 caused enrichment in regions of the apical plasma membrane not undergoing rapid expansion, whereas a GFP fusion to the PtdInsP2 binding domain of mammalian PLC delta1 caused enrichment in apical regions depleted in PLC. Thus, Pet PLC1 appears to be involved in the machinery that restricts growth to the very apex of the elongating pollen tube, likely through its regulatory action on PtdInsP2 distribution within the cell.
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Affiliation(s)
- Peter E Dowd
- Department of Biochemistry and Molecular Biology, Pensylvania State University, University Park, Pensylvania 16802, USA
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Sijacic P, Wang X, Skirpan AL, Wang Y, Dowd PE, McCubbin AG, Huang S, Kao TH. Identification of the pollen determinant of S-RNase-mediated self-incompatibility. Nature 2004; 429:302-5. [PMID: 15152253 DOI: 10.1038/nature02523] [Citation(s) in RCA: 251] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Accepted: 03/30/2004] [Indexed: 11/09/2022]
Abstract
Many flowering plants have adopted self-incompatibility mechanisms to prevent inbreeding and promote out-crosses. In the Solanaceae, Rosaceae and Scrophulariaceae, two separate genes at the highly polymorphic S-locus control self-incompatibility interactions: the S-RNase gene encodes the pistil determinant and the previously unidentified S-gene encodes the pollen determinant. S-RNases interact with pollen S-allele products to inhibit the growth of self-pollen tubes in the style. Pollen-expressed F-box genes showing allelic sequence polymorphism have recently been identified near to the S-RNase gene in members of the Rosaceae and Scrophulariaceae; but until now have not been directly shown to encode the pollen determinant. Here we report the identification and characterization of PiSLF, an S-locus F-box gene of Petunia inflata (Solanaceae). We show that transformation of S1S1, S1S2 and S2S3 plants with the S2-allele of PiSLF causes breakdown of their pollen function in self-incompatibility. This breakdown of pollen function is consistent with 'competitive interaction', in which pollen carrying two different pollen S-alleles fails to function in self-incompatibility. We conclude that PiSLF encodes the pollen self-incompatibility determinant.
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Affiliation(s)
- Paja Sijacic
- Integrative Biosciences Graduate Degree Program, The Pennsylvania State University, 403 Althouse Laboratory, University Park, Pennsylvania 16802, USA
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Abstract
The Solanaceae, Rosaceae, and Scrophulariaceae families all possess an RNase-mediated self-incompatibility mechanism through which their pistils can recognize and reject self-pollen to prevent inbreeding. The highly polymorphic S-locus controls the self-incompatibility interaction, and the S-locus of the Solanaceae has been shown to be a multi-gene complex in excess of 1.3 Mb. To date, the function of only one of the S-locus genes, the S-RNase gene, has been determined. This article reviews the current status of the search for the pollen S-gene and the current models for how S-haplotype specific inhibition of pollen tubes can be accomplished by S-RNases.
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Affiliation(s)
- Yan Wang
- Intercollege Graduate Degree Program in Plant Physiology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Skirpan AL, McCubbin AG, Ishimizu T, Wang X, Hu Y, Dowd PE, Ma H, Kao T. Isolation and characterization of kinase interacting protein 1, a pollen protein that interacts with the kinase domain of PRK1, a receptor-like kinase of petunia. Plant Physiol 2001; 126:1480-92. [PMID: 11500547 PMCID: PMC117148 DOI: 10.1104/pp.126.4.1480] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2001] [Revised: 03/27/2001] [Accepted: 04/23/2001] [Indexed: 05/21/2023]
Abstract
Many receptor-like kinases have been identified in plants and have been shown by genetic or transgenic knockouts to play diverse physiological roles; however, to date, the cytosolic interacting proteins of relatively few of these kinases have been identified. We have previously identified a predominantly pollen-expressed receptor-like kinase of petunia (Petunia inflata), named PRK1, and we have shown by the antisense RNA approach that it is required for microspores to progress from the unicellular to bicellular stage. To investigate the PRK1-mediated signal transduction pathway, PRK1-K cDNA, encoding most of the cytoplasmic domain of PRK1, was used as bait in yeast (Saccharomyces cerevisiae) two-hybrid screens of pollen/pollen tube cDNA libraries of petunia. A protein named kinase interacting protein 1 (KIP1) was found to interact very strongly with PRK1-K. This interaction was greatly reduced when lysine-462 of PRK1-K, believed to be essential for kinase activity, was replaced with arginine (the resulting protein is named PRK1-K462R). The amino acid sequence of KIP1 deduced from full-length cDNA contains an EF-hand Ca(2+)-binding motif and nine predicted coiled-coil regions. The yeast two-hybrid assay and affinity chromatography showed that KIP1 interacts with itself to form a dimer or higher multimer. KIP1 is present in a single copy in the genome, and is expressed predominantly in pollen with a similar temporal pattern to PRK1. In situ hybridization showed that PRK1 and KIP1 transcripts were localized in the cytoplasm of pollen. PRK1-K phosphorylated KIP1-NT (amino acids 1--716), whereas PRK1-K462R only weakly phosphorylated KIP1-NT in vitro.
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Affiliation(s)
- A L Skirpan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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