Using high-throughput multiple optical phenotyping to decipher the genetic architecture of maize drought tolerance

Area of Science:

• Plant Science
• Genetics
• Agricultural Science

Background:

• Drought poses a significant threat to global food security.
• Understanding plant responses to drought is essential for developing resilient crops.
• Genetic factors influencing drought tolerance in crops are largely unknown.

Purpose of the Study:

• To develop and apply a high-throughput optical phenotyping system for dissecting maize drought responses.
• To identify genetic loci and candidate genes associated with drought tolerance using genome-wide association studies (GWAS).
• To validate novel genes involved in maize drought tolerance.

Main Methods:

• A high-throughput multiple optical phenotyping system was used to image 368 maize genotypes under drought stress.
• Image-based traits (i-traits) were extracted using advanced analysis pipelines.
• Genome-wide association study (GWAS) and expression quantitative trait loci (eQTL) analyses were performed.

Main Results:

• 10,080 effective and heritable i-traits were identified as indicators of drought response.
• GWAS revealed 4322 significant locus-trait associations, identifying 1529 quantitative trait loci (QTLs) and 2318 candidate genes.
• Two novel genes, ZmcPGM2 and ZmFAB1A, were validated for their role in drought tolerance.

Conclusions:

• Combining high-throughput phenotyping with GWAS is an effective strategy for understanding complex trait genetics.
• This approach facilitates the identification and cloning of genes associated with drought tolerance.
• Identified i-traits and genes offer potential markers for breeding drought-tolerant maize varieties.