Molecular regulation of fruit size in horticultural plants: A review

Abstract Fruit is a specific organ of angiosperms that develops from ovary or other parts of flower after the pistil is pollinated and fertilized. Fruit size is a key indicator of fruit yield and quality, and an adaptive feature of evolution in horticultural plants which are becoming increasingly important for human life. Unveiling the molecular pathways that regulate fruit size development has both scientific and economic significance. The final size of fruit relies on the coordinated control of cell division and cell expansion. Several molecular mechanisms are involved in the determination of fruit size, including hormonal regulation (IAA, GA, CK, ABA, ETH and BRs), CLV-WUS signaling pathway, MADS-box family, ubiquitin-proteasome pathway, quantitative trait loci (QTLs), MicroRNA and endoreduplication. This review describes the current findings on regulation mechanisms of fruit size development in horticultural plants, and the prospects for studying fruit size development are also discussed.