Pollination Regulation of Flower Development

Abstract

Pollination regulates a syndrome of developmental responses that contributes to successful sexual reproduction in higher plants. Pollination-regulated developmental events collectively prepare the flower for fertilization and embryogenesis while bringing about the loss of floral organs that have completed their function in pollen dispersal and reception. Components of this process include changes in flower pigmentation, senescence and abscission of floral organs, growth and development of the ovary, and, in certain cases, pollination also triggers ovule and female gametophyte development in anticipation of fertilization. Pollination-regulated development is initiated by the primary pollination event at the stigma surface, but because developmental processes occur in distal floral organs, the activity of interorgan signals that amplify and transmit the primary pollination signal to floral organs is implicated. Interorgan signaling and signal amplification involves the regulation of ethylene biosynthetic gene expression and interorgan transport of hormones and their precursors. The coordination of pollination- regulated flower development including gametophyte, embryo, and ovary development; pollination signaling; the molecular regulation of ethylene biosynthesis; and interorgan communication are presented.

Whole Genome Analysis of Gene Expression Reveals Coordinated Activation of Signaling and Metabolic Pathways during Pollen-Pistil Interactions in Arabidopsis

“…Therefore, their dynamic regulation may indicate that a precise control of the local concentrations for defined hormonal metabolites might be essential to regulate downstream signaling events along the pollen tube pathway. Several studies suggested that certain hormones such as ethylene, auxin, brassinosteroids, and methyl jasmonate could act as primary signals in the pollination response (O'Neill, 1997). Supporting an important role of hormones in the success of the reproductive process (Aloni et al, 2006;Chen and Zhao, 2008), we identified several biosynthetic and signaling-related components of the auxin (Supplemental Fig.…”

Control of petal shape and floral zygomorphy in Lotus japonicus

“…F loral zygomorphy (dorsoventral asymmetry) is an evolutionary adaptation that facilitates outcrossing by attracting pollinators (1)(2)(3)(4)(5)(6)(7). The phenomenal diversity in Leguminosae (Rosid clade of eudicots), the third largest family of flowering plants with Ϸ20,000 species (8), is often explained by successful coevolution with pollinators.…”

Programmed senescence of plant organs

“…Other flowers, such as petunia, gradually senesce over a period of days after flower opening, but this process is accelerated by pollination. In still other flowers perianth senescence is absolutely dependent on pollination and in these cases the external stimuli and endogenous signals that regulate programmed senescence have been examined in detail (O'Neill et al, 1993;O'Neill and Nadeau, 1997;O'Neill, 1997).…”