Sorghum sugarcane aphid resistance breeding using genomics and genome editing

Overview

Sugarcane aphid (SCA) is a major insect pest of sorghum that emerged in North America in 2013 and now threatens sorghum production across key growing regions. Sorghum is the fifth most cultivated cereal crop worldwide and is increasingly important for both food security and biofuel supply. This research program focuses on dissecting the genetic basis of SCA resistance in the sorghum line Tx2783, which carries a rare large insertion allele associated with strong resistance to the pest. By combining genomics with genome-editing tools, the work aims to pinpoint the causal gene(s) and regulatory elements responsible for resistance and translate these findings into accelerated breeding of SCA-resistant sorghum cultivars.

Technical specifications

Core approach:

• Deep mining of SCA resistance alleles from the resistant accession Tx2783
• Integration of genomics with genome-editing technologies to create targeted mutations
• Use of a genotype-independent transformation system in sorghum that combines developmental regulators with genome-editing reagents
• Design of Tx2783-specific multiple guide RNAs to target candidate genes and regulatory elements within the resistant insertion allele
• Generation of a series of allelic variants to functionally validate the causal gene or regulatory element underlying SCA resistance

Key features:

• Addresses a rare large insertion allele linked to several novel genes and regulatory elements
• Establishes a transformation and genome-editing pipeline specifically for Tx2783
• Supports both gene discovery and downstream trait deployment for pest resistance breeding

Technology readiness level

The program is at an early-to-mid research stage. The resistant accession Tx2783 has been identified and a rare large insertion allele associated with SCA resistance has been characterized. A genotype-independent sorghum transformation system using developmental regulators is already in use. Current and planned work focuses on establishing the Tx2783 transformation and editing workflow, designing multi-gRNA constructs, and functionally validating the causal gene(s) and regulatory elements through allelic series analysis. Additional validation, field testing, and breeding integration will be required before commercial deployment.