A transcription factor TaMYB5 modulates leaf rolling in wheat.

Area of Science:

• Plant genetics
• Agronomy
• Molecular biology

Background:

• Leaf rolling is a key trait in wheat (Triticum aestivum L.) for managing drought stress by maintaining photosynthesis.
• The precise molecular mechanisms governing wheat leaf rolling are not yet fully understood.

Purpose of the Study:

• To identify genes regulating leaf rolling in wheat using genome-wide association study (GWAS).
• To elucidate the molecular mechanism of TaMYB5-3A in controlling leaf rolling and its association with physiological traits.

Main Methods:

• Genome-wide association study (GWAS) on 323 wheat accessions.
• Phenotypic analysis of tmyb5 mutants under drought conditions.
• Gene expression analysis, electrophoretic mobility shift assay (EMSA), and association analysis with canopy temperature (CT).

Main Results:

• A candidate gene, TaMYB5-3A, was identified as a regulator of wheat leaf rolling.
• Nucleotide variations in TaMYB5-3A (SNP-3A-1 and SNP-3A-2 alleles) correlated with leaf rolling index (LRI) and canopy temperature (CT).
• TaMYB5-3A directly induces TaNRL1 gene expression in leaves, and its expression is reduced by PEG and ABA treatments.

Conclusions:

• TaMYB5-3A plays a crucial role in the molecular mechanism of wheat leaf rolling under drought stress.
• The identified gene and its alleles provide a basis for improving drought tolerance in wheat through breeding.