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Article|08 Nov 2023|OPEN
Promoter insertion leads to polyembryony in mango — a case of convergent evolution with citrus
Chandra Bhan Yadav1,2 , Ada Rozen1 , Ravit Eshed1 , Mazal Ish-Shalom1 , Adi Faigenboim1 , Natalie Dillon3 , , Ian Bally3 , Matthew Webb4 , David Kuhn5 , Ron Ophir1 and Yuval Cohen1 , , Amir Sherman,1 ,
1Institute of Plant Sciences, Volcani Research Center, Derech Hamacabim 68, Rishon LeZion, P.O. Box 15159, 7528809, Israel
2Department of Genetics, Genomics, and Breeding, NIAB-EMR, East Malling, ME19 6BJ, United Kingdom
3Department of Agriculture and Fisheries, Horticulture and Forestry Science, 28 Peters St, Mareeba, QLD 4880, Australia
4Department of Agriculture and Fisheries, Horticulture and Forestry Science, Ecosciences Precinct, 41 Boggo Road, Dutton Park, Brisbane, QLD 4001, Australia
5Subtropical Horticulture Research Station, USDA-ARS, 13601 Old Cutler Rd, Coral Gables, FL 33158, United States
*Corresponding author. E-mail: vhyuvalc@volcani.agri.gov.il,asherman@agri.gov.il

Horticulture Research 11,
Article number: uhad227 (2024)
doi: https://doi.org/10.1093/hr/uhad227
Views: 42

Received: 09 May 2023
Accepted: 29 Oct 2023
Published online: 08 Nov 2023

Abstract

Sexual reproduction in plants is the main pathway for creating new genetic combinations in modern agriculture. In heterozygous plants, after the identification of a plant with desired traits, vegetative propagation (cloning) is the primary path to create genetically uniform plants. Another natural plant mechanism that creates genetically uniform plants (clones) is apomixis. In fruit crops like citrus and mango, sporophytic apomixis results in polyembryony, where seeds contain multiple embryos, one of which is sexually originated and the others are vegetative clones of the parent mother tree. Utilizing the mango genome and genetic analysis of a diverse germplasm collection, we identified MiRWP as the gene that causes polyembryony in mango. There is a strong correlation between a specific insertion in the gene’s promoter region and altered expression in flowers and developing fruitlets, inducing multiple embryos. The MiRWP gene is an ortholog of CitRWP that causes polyembryony in citrus. Based on the data, we speculate that promoter insertion events, which occurred independently in citrus and mango, induced nucellar embryogenesis. The results suggest convergent evolution of polyembryony in the two species. Further work is required to demonstrate the utility of these genes (mango and citrus) in other biological systems as a tool for the clonal production of other crops.