Promoter analysis of genes that are coordinately expressed during pollen development reveals pollen-specific enhancer sequences and shared regulatory elements.

Abstract

We have investigated the functional organization and properties of cis regulatory elements in the promoter regions of two genes from tomato (LAT52 and LAT59) that are preferentially and coordinately expressed during pollen maturation. Promoter deletion analysis in transgenic plants demonstrated that only minimal (~200 bp) promoter proximal regions are required for developmentally regulated expression in pollen and in specific cell types of the sporophyte. Cis-acting regulatory regions of these two promoters and of a third pollen-expressed promoter (LAT56) were characterized in detail using a transient expression assay. We identified two upstream activator regions in the LAT52 promoter and further showed that a 19-bp segment from one of those regions enhanced expression of the heterologous CaMV35S promoter in pollen. Similarities in sequence between crucial cis elements provide evidence that shared regulatory elements are involved in the coordinate expression of the LAT genes during microsporogenesis.[Key Words: Tomato; tobacco; male gametophyte; transcriptional control; enhancer; cell-specific gene regulation]Received September 28, 1990; revised version accepted January 4, 1991.Identifying the molecular components that control the spatial and temporal patterns of gene expression accompanying gametogenesis is an important step in understanding sexual reproduction in eukaryotes. We are interested in the development of the male gametophyte (pollen) of angiosperms because it provides a unique system with which to study cell-specific gene regulation and cellular differentiation during reproductive development in plants. Major cytological and biochemical events that occur during pollen development are well characterized, the mRNA populations in pollen have been analyzed, pollen-specific isoenzymes have been identified, and several genes that are preferentially expressed in pollen in a stage-specific manner recently have been cloned and sequenced (for reviews, see Mascarenhas 1975Mascarenhas , 1989. Of particular interest is the asymmetric mitotic division of the haploid microspore (microspore mitosis), which results in the formation of two dimorphic cells with different developmental fates. The Present addresses: ~Leicester Biocentre, University of Leicester, Leicester LE1 7RH UK;

β-Subunits of the SnRK1 Complexes Share a Common Ancestral Function Together with Expression and Function Specificities; Physical Interaction with Nitrate Reductase Specifically Occurs via AKINβ1-Subunit

“…2). However, this sequence differs slightly from those previously identified (Twell et al, 1991;Weterings et al, 1995;Bate and Twell, 1998; TGTTGGTT instead of TGTGGTT). One sugar-repressive box (Morita et al, 1998) has also been found in this promoter (Fig.…”

“…However, digital northern analysis carried out with Genevestigator (Zimmermann et al, 2004; https:// www.genevestigator.ethz.ch) did not reveal any potential regulation by auxin. One pollen box is present (Twell et al, 1991), as well as two dark induction or light repression boxes (Dehesh et al, 1990;Inaba et al, 2000;Fig. 2).…”

“…In the AKINb2 promoter (998 bp from transcription start site), a domain similar to the LAT56 pollen motif is present (Twell et al, 1991;Fig. 2).…”

“…2). Seven AAATGA boxes are on the major strand and three on the minus strand (Weterings et al, 1995) as well as three LAT56-type pollen boxes (Twell et al, 1991). A dark induction box (Dehesh et al, 1990) is present in the exonic region located between the two leader introns (Fig.…”

DNA Sequences That Activate Isocitrate Lyase Gene Expression during Late Embryogenesis and during Postgerminative Growth

“…Although others have found such transient assays to be reliable methods to measure gene activities, we have relied on the data obtained from the analyses of transgenic plants to study the isocitrate lyase 5' flanking region because of the potential problems in interpreting the results of the bombardment experiments (Klein et al, 1988(Klein et al, , 1989Bruce et al, 1989;Goff et al, 1990;Rolfe and Tobin, 1991;Twell et al, 1991).…”