The DAL10 gene from Norway spruce (Picea abies) belongs to a potentially gymnosperm‐specific subclass of MADS‐box genes and is specifically active in seed cones and pollen cones

Abstract

Transcription factors encoded by different members of the MADS-box gene family have evolved central roles in the regulation of reproductive organ development in the flowering plants, the angiosperms. Development of the stamens and carpels, the pollen- and seed-bearing organs, involves the B- and C-organ-identity MADS-box genes. B- and C-type gene orthologs with activities specifically in developing pollen- and seed-bearing organs are also present in the distantly related gymnosperms: the conifers and the gnetophytes. We now report on the characterization of DAL10, a novel MADS-box gene from the conifer Norway spruce, which unlike the B- and C-type conifer genes shows no distinct orthology relationship to any angiosperm gene or clade in phylogenetic analyses. Like the B- and C-type genes, it is active specifically in developing pollen cones and seed cones. In situ RNA localization experiments show DAL10 to be expressed in the cone axis, which carry the microsporophylls of the young pollen cone. In contrast, in the seed cone it is expressed both in the cone axis and in the bracts, which subtend the ovuliferous scales. Expression data and the phenotype of transgenic Arabidopsis plants expressing DAL10 suggest that the gene may act upstream to or in concert with the B- and C-type genes in the establishment of reproductive identity of developing cones.

Mutant analysis, protein–protein interactions and subcellular localization of the Arabidopsis Bsister (ABS) protein

“…B sister genes have some intriguing features. In phylogenetic trees, they form a sister group with class B floral homeotic genes, although this grouping is not always well supported (Becker et al 2002;Carlsbecker et al 2003;Stellari et al 2004). However, in strong contrast to B genes, B sister genes are predominantly expressed in female reproductive organs (mainly in ovules) and this expression pattern is conserved among seed plants (Becker et al 2002).…”

Early Cone Setting in Picea abies acrocona Is Associated with Increased Transcriptional Activity of a MADS Box Transcription Factor

“…Interestingly, we observed differential expression of the DAL10 gene, which belongs to a gymnosperm-specific clade of the MADS box gene family. DAL10 has been suggested to be a marker for reproductive shoot identity (Carlsbecker et al, 2003) and is expressed in buds after, but not before, the phase change from vegetative to reproductive growth. Hence, the data presented here suggest that DAL10 is activated as a result of reproductive competence, whereas upregulation of DAL19 coincides with or precedes reproductive phase change.…”

“…In addition, the expression of DAL1 in transgenic Arabidopsis shortens the vegetative phase, and the plants begin to flower extremely early, sometimes forming embryonic flowers (Carlsbecker et al, 2004). Similarly, the spatial expression patterns of the Norway spruce gene DAL10 together with phenotypic studies of Arabidopsis plants, harboring DAL10 under the control of a constitutive promoter, suggest that this MADS box gene may be involved in specifying reproductive identity in the male and female shoots (cones) of Norway spruce (Carlsbecker et al, 2003).…”

“…Studies of transcriptional regulators belonging to the MADS box gene family in Norway spruce suggest that members of this gene family have putative functions in determining the length of the juvenile period and the vegetative or reproductive identity of a shoot (Carlsbecker et al, 2003(Carlsbecker et al, , 2004. Expression of the gene DEFICIENS AGAMOUS-LIKE1 (DAL1) increases with age and conforms to a spatial pattern that marks physiological and morphological features associated with the transition to the reproductive phase.…”

"Estudo do desenvolvimento floral em espécies arbóreas da família Meliaceae"

“…A elucidação de aspectos genéticos e moleculares relacionados ao florescimento (Koorneef et al 1991;Weigel et al 1992;Coupland, 1995;Kramer & Irish, 1999;Honma & Goto, 2001;Hong et al 2003, Ferrario et al, 2004, Zahn et al, 2005, tem avançado grandemente através de estudos de clonagem e caracterização de genes envolvidos no desenvolvimento floral (Weigel, 1995;LawtonRauch et al 2000), inicialmente em plantas-modelo como Arabidopsis thaliana e Antirrhinum majus. Atualmente, esses estudos têm sido estendidos a outros grupos de plantas como em gimnospermas: Picea abies (Tandre et al 1995(Tandre et al , 1998Carlsbecker et al, 2003;Sundstrom et al 1999), P. mariana (Rutledge et al 1998), Ginkgo biloba (Jager et al, 2003); e em angiospermas monocotiledôneas, tais como: Zea mays (Mena et al 1998;Schmidt & Ambrose, 1998) e Orysa sativa (Kang et al 1998, Prasad et al, 2001), e em angiospermas dicotiledônias como o girassol (Dezar et al, 2003), Petunia hybrida (Ferrario et al, 2003) e tomate (Hart & Hannapel, 2002).…”