Genome-wide identification and characterization of NAC transcription factor-derived microsatellites in wheat (Triticum aestivum L.)

Bread wheat (Triticum aestivum L.) is one of the widely consumed staple foods, providing 20% of the total protein and calories in human nutrition. Seeing its importance in the global food supply, the enrichment of functional genomic resources is vital for meeting future demands and ensuring sustainable production. In addition to the presence of functional domains, the presence of microsatellites within transcription factors makes them valuable candidates for enriching functional marker resources. The NAC transcription factor family regulates a variety of physiological processes in cereal crops. Hence, the present study aims to develop and characterize Triticum aestivum NAC MicroSatellites (TaNACMS) to enrich functional marker resources for genetic diversity analysis, marker-assisted selection, and evolutionary studies. In total, 520 SSRs were identified from 451 TaNAC sequences, and a set of 66 TaNACMS was used for cross-transferability in wild/related wheat species. The cross-transferability rate of 90.22% revealed high locus conservation. Further, 16 TaNACMS were utilized for the characterization of genetic diversity in Indian wheat varieties. These TaNACMS produced 40 alleles (2.5 alleles per locus) with an average observed heterozygosity (Ho), expected heterozygosity (He), and polymorphic information content (PIC) of 0.392, 0.417, and 0.380, respectively. The genetic analysis of wheat genotypes, using principal coordinates analysis (PCoA), neighbor-joining (NJ) clustering, and Bayesian-based STRUCTURE, has revealed three distinct genetic clusters. Two of these clusters consist of Indian wheat varieties, while the third cluster comprises wild/related wheat species. In conclusion, the high rate of transferability of TaNACMS can be effectively utilized for gene flow both within and between species, highlighting evolutionary connections between cultivated wheat and related species. Additionally, these SSRs will aid the marker repository and benefit the wheat improvement programs through marker-assisted selection (MAS).