Recoloring tomato fruit by CRISPR/Cas9-mediated multiplex gene editing

Area of Science:

• Horticultural Science
• Plant Genetics
• Molecular Biology

Background:

• Fruit color is a key trait influencing consumer choice in tomatoes.
• Tomato fruit coloration results from complex interactions of pigments (carotenoids, flavonoids) and chlorophyll degradation.
• Traditional crossbreeding for multigenic traits like fruit color is time-consuming and prone to linkage drag.

Purpose of the Study:

• To develop a rapid breeding strategy for generating diverse tomato fruit colors.
• To utilize CRISPR/Cas9-mediated multiplex gene editing for precise modification of fruit color genes.
• To engineer specific tomato genotypes with altered fruit colors from red-fruited cultivars.

Main Methods:

• CRISPR/Cas9-mediated multiplex gene editing targeting three key fruit color genes: PSY1, MYB12, and SGR1.
• Application of the gene editing strategy to the red-fruited tomato cultivar 'Ailsa Craig'.
• Evaluation of generated tomato lines for fruit color variations and agronomic traits.

Main Results:

• Successfully generated tomato lines with a range of fruit colors including yellow, brown, pink, light-yellow, pink-brown, yellow-green, and light green.
• Achieved transgene-free plants with diverse fruit colors in under one year, significantly faster than traditional methods.
• Confirmed that the gene editing strategy did not negatively affect important agronomic traits such as yield and fruit quality.

Conclusions:

• The CRISPR/Cas9 multiplex gene editing strategy offers a rapid and efficient method for tomato breeding.
• This approach provides a valuable tool for developing novel fruit colors and improving horticultural crops with multigene-controlled traits.
• The method minimizes undesirable linkage drag, preserving essential agronomic characteristics.