Auxin synthesis-encoding transgene enhances grape fecundity

Area of Science:

• Plant Science
• Agricultural Biotechnology
• Genetics

Background:

• Grape yield in Vitis vinifera is primarily determined by cultivar fecundity, influenced by traits like shoot fruitfulness and berry development.
• Understanding the genetic factors controlling inflorescence and berry development is crucial for improving grape production.

Purpose of the Study:

• To investigate the effect of an ovule-specific auxin-synthesizing transgene (DefH9-iaaM) on grape yield components in Vitis vinifera cultivars.
• To assess the impact of increased auxin levels on shoot fruitfulness, berry number, and overall fruit quality.

Main Methods:

• Transformation of Vitis vinifera cultivars Silcora and Thompson Seedless with the DefH9-iaaM transgene.
• Comparison of transgenic lines with wild-type controls for shoot fruitfulness, berry number per bunch, and berry weight.
• Analysis of berry quality and nutritional content in transgenic versus control grapes.

Main Results:

• The DefH9-iaaM transgene doubled the average number of inflorescences per shoot in Thompson Seedless compared to its wild-type.
• Transgenic cultivars exhibited increased berry number per bunch.
• Transgenic berries maintained equivalent quality and nutritional value compared to control fruits.

Conclusions:

• The study demonstrates that enhanced auxin synthesis via the DefH9-iaaM transgene significantly improves grape fecundity and yield.
• Auxin plays a key role in enhancing shoot fruitfulness and berry development in Vitis vinifera.
• This genetic approach offers a potential strategy for increasing grape yield and reducing production costs.