Outstanding questions in flower metabolism

Abstract

Summary The great diversity of flowers, their color, odor, taste, and shape, is mostly a result of the metabolic processes that occur in this reproductive organ when the flower and its tissues develop, grow, and finally die. Some of these metabolites serve to advertise flowers to animal pollinators, other confer protection towards abiotic stresses, and a large proportion of the molecules of the central metabolic pathways have bioenergetic and signaling functions that support growth and the transition to fruits and seeds. Although recent studies have advanced our general understanding of flower metabolism, several questions still await an answer. Here, we have compiled a list of open questions on flower metabolism encompassing molecular aspects, as well as topics of relevance for agriculture and the ecosystem. These questions include the study of flower metabolism through development, the biochemistry of nectar and its relevance to promoting plant‐pollinator interaction, recycling of metabolic resources after flowers whiter and die, as well as the manipulation of flower metabolism by pathogens. We hope with this review to stimulate discussion on the topic of flower metabolism and set a reference point to return to in the future when assessing progress in the field.

Accumulation of Secondary Metabolites of Rhodiola semenovii Boriss. In Situ in the Dynamics of Growth and Development

“…If the main function of leaves during the flowering stage is to fix CO 2 through photosynthesis (source), then flowers (as a sink) are largely dependent on organic molecules synthesized in leaves and roots [ 53 ]. Nevertheless, flowers are not just a sink of carbohydrates and amino acids.…”

Cross-Species Metabolic Profiling of Floral Specialized Metabolism Facilitates Understanding of Evolutional Aspects of Metabolism Among Brassicaceae Species

“…With few exceptions flowers in angiosperms are responsible for producing the next generation, therefore specialized metabolites in flowers serve the purpose of attracting pollinators, playing protective roles to against biotic or abiotic stress such as UV-irradiation or herbivory, and being an important constitution allowing the maintenance of normal fertility (Tohge et al, 2018;Borghi et al, 2019;Borghi and Fernie, 2020). Successful fertilization involves certain metabolite groups, for example, phenolic acids derivatives and flavonols function as important UV-absorbing compounds, some of which are essential to maintain pollen activity (Xue et al, 2020), phenolamides play unique role for fertility (Bassard et al, 2010), and glucosinolates are involve in plant-insect interaction (Liu et al, 2020).…”

Plant Single-Cell Metabolomics—Challenges and Perspectives

“…Progress has also been made in the analysis of lipids, proteins, and the mechanisms of accumulation of flavonoid glycosides on the surface of pollen grains [90][91][92][93], as well as the metabolic processes underlying pollen germination and pollen tube elongation [94]. However, given the complexity of these chemical signals, their physiological function is not yet fully understood [95]. Finally, we briefly mention here that while collecting abundant pollen from male microsporangia of gymnosperms is usually easy endeavors, autogamous angiosperms generally produce a tiny amount of pollen, for which the collection of whole anthers is a necessary step.…”