Articles
Intragenic approach for remontant strawberry
Article number
1444_1
Pages
1 – 8
Language
English
Abstract
The development of commercial octoploid cultivars with high quality and perpetual flowering (PF) character remains an important goal in the breeding of this crop.
However, achieving this milestone is challenging with standard hybridization, as the genetic control underlying PF is still under study.
The flowering locus T2 gene of Fragaria vesca (FveFT2) has been recently validated as the non-photoperiodic florigen, which allows short-day flowering when overexpressed in both diploid and octoploid cultivars, acting as a long-distance floral signal in strawberry.
The advancement of new genomic techniques, such as cisgenesis and intragenesis, has led to the development of strategies that enable the genetic improvement of plants through methods that do not involve the use of foreign genetic material, including genes of bacterial or viral origin, thereby meeting public acceptance and less restrictive regulatory procedures.
In this study, the FveFT2 gene was inserted into three new intragenic constructs composed of regulatory regions and selectable/reporter genes isolated from cultivated strawberry, Fragaria × ananassa. In vitro leaves of the short-day strawberry cultivar ‘Romina’ (F. × ananassa) were used as initial explants for Agrobacterium tumefaciens-mediated transformation assays.
One of the three constructs, which also encodes the EPSPS gene of the octoploid strawberry as a selectable marker, providing greater resistance to the herbicide glyphosate, has favored the regeneration and proliferation of several positive lines, as indicated by preliminary PCR analysis.
The other two constructs, which lack a selection gene in the T-DNA sequence, only led to the regeneration of chimeric or non-transformed shoots, highlighting the difficulty in obtaining cisgenic/intragenic lines through these kinds of systems.
The confirmed lines transformed with the construct FveFt2::FaEPSPs will be phenotypically characterized to confirm the acquisition of the PF character.
This result will pave the way for future studies to apply this strategy to other June-bearing octoploid strawberry cultivars of commercial interest, and to obtain plants with a lower biosafety impact and greater public acceptance.
However, achieving this milestone is challenging with standard hybridization, as the genetic control underlying PF is still under study.
The flowering locus T2 gene of Fragaria vesca (FveFT2) has been recently validated as the non-photoperiodic florigen, which allows short-day flowering when overexpressed in both diploid and octoploid cultivars, acting as a long-distance floral signal in strawberry.
The advancement of new genomic techniques, such as cisgenesis and intragenesis, has led to the development of strategies that enable the genetic improvement of plants through methods that do not involve the use of foreign genetic material, including genes of bacterial or viral origin, thereby meeting public acceptance and less restrictive regulatory procedures.
In this study, the FveFT2 gene was inserted into three new intragenic constructs composed of regulatory regions and selectable/reporter genes isolated from cultivated strawberry, Fragaria × ananassa. In vitro leaves of the short-day strawberry cultivar ‘Romina’ (F. × ananassa) were used as initial explants for Agrobacterium tumefaciens-mediated transformation assays.
One of the three constructs, which also encodes the EPSPS gene of the octoploid strawberry as a selectable marker, providing greater resistance to the herbicide glyphosate, has favored the regeneration and proliferation of several positive lines, as indicated by preliminary PCR analysis.
The other two constructs, which lack a selection gene in the T-DNA sequence, only led to the regeneration of chimeric or non-transformed shoots, highlighting the difficulty in obtaining cisgenic/intragenic lines through these kinds of systems.
The confirmed lines transformed with the construct FveFt2::FaEPSPs will be phenotypically characterized to confirm the acquisition of the PF character.
This result will pave the way for future studies to apply this strategy to other June-bearing octoploid strawberry cultivars of commercial interest, and to obtain plants with a lower biosafety impact and greater public acceptance.
Authors
V. Súnico, B. Mezzetti, A. Gaston, B. Denoyes, J.L. Caballero, K. Folta, I. Verde, S. Sabbadini
Keywords
Fragaria spp., flowering locus T, new genomic techniques, cisgenesis, intragenesis
Groups involved
- Division Vine and Berry Fruits
- Division Plant-Environment Interactions in Field Systems
- Division Horticulture for Human Health
- Working Group Vaccinium Species and Management
- Working Group Rubus and Ribes Species and Management
- Working Group Kiwifruit Culture and Management
- Working Group Strawberry Culture and Management
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