Molecular Characterization and Phylogenetic Analysis of MADS-Box Gene VroAGL11 Associated with Stenospermocarpic Seedlessness in Muscadine Grapes.

M Atikur Rahman,Subramani P Balasubramani,Sheikh M Basha

doi:10.3390/genes12020232

M Atikur Rahman, Subramani P Balasubramani + Show 1 more

Open Access

https://doi.org/10.3390/genes12020232

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Journal: Genes	Publication Date: Feb 5, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: Florida Agricultural and Mechanical University

Abstract

Reduced expression of MADS-box gene AGAMOUS-LIKE11 (VviAGL11) is responsible for stenospermocarpic seedlessness in bunch grapes. This study is aimed to characterize the VviAGL11 orthologous gene (VroAGL11) in native muscadine grapes (Vitis rotundifolia) at the molecular level and analyze its divergence from other plants. The VroAGL11 transcripts were found in all muscadine cultivars tested and highly expressed in berries while barely detectable in leaves. RT-PCR and sequencing of predicted ORFs from diverse grape species showed that AGL11 transcripts were conservatively spliced. The encoded VroAGL11 protein contains highly conserved MADS-MEF2-like domain, MADS domain, K box, putative phosphorylation site and two sumoylation motifs. The muscadine VroAGL11 proteins are almost identical (99%) to that of seeded bunch cultivar, Chardonnay, except in one amino acid (A79G), but differs from mutant protein of seedless bunch grape, Sultanina, in two amino acids, R197L and T210A. Phylogenetic analysis showed that AGL11 gene of muscadine and other Vitis species formed a separate clade than that of other eudicots and monocots. Muscadine grape cultivar “Jane Bell” containing the highest percentage of seed content in berry (7.2% of berry weight) had the highest VroAGL11 expression, but almost none to nominal expression in seedless cultivars Fry Seedless (muscadine) and Reliance Seedless (bunch). These findings suggest that VroAGL11 gene controls the seed morphogenesis in muscadine grapes like in bunch grape and can be manipulated to induce stenospermocarpic seedlessness using gene editing technology.

Highlights

The native muscadine grapes (Vitis rotundifolia) are grown in the Southeastern USA mainly for fresh fruit and wine production, generating USD 1.6 billion total taxes in 2017 alone in Florida [1]
In stenospermocarpy the berry size is not, or less, compromised; stenospermocarpic seedlessness is more popularly used in the production of seedless table grape cultivars
Florida hybrid bunch, and bunch grape cultivars grown at the Center for Viticulture and Small Fruit Research at Florida A&M University (FAMU), Tallahassee were used for this study

Summary

Introduction

The native muscadine grapes (Vitis rotundifolia) are grown in the Southeastern USA mainly for fresh fruit and wine production, generating USD 1.6 billion total taxes in 2017 alone in Florida [1]. They have long been cherished for their distinct fruity flavor and a number of health benefits including antioxidant, anti-inflammatory, anti-cancer, and antiaging potentiality [2,3,4]. In stenospermocarpy the berry size is not, or less, compromised; stenospermocarpic seedlessness is more popularly used in the production of seedless table grape cultivars.

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