A Truncated WRKY Protein Enhances Drought Resistance in Wild Tomatoes Through the SlWRKY16-CIP2b-SlSYP121 Module

Area of Science:

• Plant Biology
• Genetics
• Molecular Biology

Background:

• Drought stress significantly impacts plant growth and food security.
• Identifying drought resistance genes and their regulation is crucial for crop improvement.

Purpose of the Study:

• To identify genetic factors and regulatory mechanisms conferring drought tolerance in tomato.
• To elucidate the role of the SlWRKY16 gene and its interaction with other proteins in drought response.

Main Methods:

• CRISPR/Cas9 gene editing to create SlWRKY16 knockout and overexpression lines.
• Yeast two-hybrid screening to identify protein interactions.
• RNA-sequencing and electrophoretic mobility shift assays to analyze gene expression and DNA binding.

Main Results:

• A natural SNP in SlWRKY16 leads to a truncated protein, enhancing drought tolerance.
• SlWRKY16 interacts with CIP2b, and this interaction modulates SlWRKY16's binding to the SlSYP121 promoter.
• SlSYP121 acts as a positive regulator of drought tolerance, with its expression repressed by functional SlWRKY16.

Conclusions:

• A novel SlWRKY16-CIP2b-SlSYP121 regulatory module controlling drought tolerance in tomato was identified.
• The study highlights a key SNP linked to drought tolerance differences between wild and cultivated tomato.
• Findings advance understanding of molecular mechanisms underlying plant drought resistance.