Developmental Morphology, Physiology, and Molecular Basis of the Pentagram Fruit of <i>Averrhoa carambola</i>
Wanli Tuo,
Chunmei Wu,
Xuexuan Wang,
Zirui Yang,
Lianhuan Xu,
Siyuan Shen,
Junwen Zhai,
Shasha Wu
Affiliations
Wanli Tuo
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Chunmei Wu
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Xuexuan Wang
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Zirui Yang
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Lianhuan Xu
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Siyuan Shen
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Junwen Zhai
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Shasha Wu
Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou 350002, China
Averrhoa carambola, a key tropical and subtropical economic tree in the Oxalidaceae family, is distinguished by its unique pentagram-shaped fruit. This study investigates the developmental processes shaping the polarity of A. carambola fruit and their underlying hormonal and genetic mechanisms. By analyzing the Y1, Y2, and Y3 developmental stages—defined by the fruit diameters of 3–4 mm, 4–6 mm, and 6–12 mm, respectively—we observed that both cell number and cell size contribute to fruit development. Our findings suggest that the characteristic pentagram shape is established before flowering and is maintained throughout development. A hormonal analysis revealed that indole-3-acetic acid (IAA) and abscisic acid (ABA) show differential distribution between the convex and concave regions of the fruit across the developmental stages, with IAA playing a crucial role in polar auxin transport and shaping fruit morphology. A transcriptomic analysis identified several key genes, including AcaGH3.8, AcaIAA20, AcaYAB2, AcaXTH6, AcaYAB3, and AcaEXP13, which potentially regulate fruit polarity and growth. This study advances our comprehension of the molecular mechanisms governing fruit shape, offering insights for improving fruit quality through targeted breeding strategies.
