Integrated Metabolome and Transcriptome Analysis Elucidates Reproductive Functional Divergence and Regulatory Mechanisms Underlying the Distinct Spatial Distribution of Female Flowers in Monoecious Figs

In the obligate mutualism between monoecious figs and their pollinating fig wasps, both partners compete for resources within the same female flowers. The mechanisms underlying floral differentiation are poorly understood. This study integrates transcriptomic and metabolomic analyses to examine female flowers of Ficus hookeriana across three key developmental stages, including the pre-female, female, and inter-floral phases, with attention to their spatial distribution within figs. We show that nucleotide metabolism regulates early differential growth during the pre-female phase. In the female phase, flavonoid biosynthesis guides functional specialization, potentially related to defense responses. During the inter-floral phase, the citrate cycle (TCA) pathway modulates resource allocation between seed and gall development, thereby influencing reproductive balance. These findings reveal stage-specific molecular and metabolic mechanisms governing resource partitioning in this mutualism, offering new insights into plant and insect interactions.