TaNAC020 homoeologous genes are associated with higher thousand kernel weight and kernel length in Chinese wheat

• Published in: Frontiers in genetics Vol. 13; p. 956921
• Main Authors: Majeed, Uzma, Hou, Jian, Hao, Chenyang, Zhang, Xueyong
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 26-08-2022
• Subjects: Genetics; KASP markers; kernel length; marker–trait association; TaNAC020; thousand kernel weight
• ISSN: 1664-8021; 1664-8021
• DOI: 10.3389/fgene.2022.956921

NAC proteins constitute one of the largest plant-specific transcription factor (TF) families and play significant roles in plant growth and development. In the present study, three
TaNAC020
homoeologous genes located on chromosomes 7A, 7B, and 7D were isolated from wheat (
Triticum aestivum
L.).
TaNAC020s
were predominantly expressed in developing grains. The developed transgenic rice lines for
TaNAC020-B
showed higher starch density and lower amylose contents than those of the wild type (WT). Sequence polymorphism studies showed seven and eight SNPs in
TaNAC020-A/B
, making three and two haplotypes, respectively. No sequence polymorphism was identified in
TaNAC020-D
. Association analysis revealed that HAP-2 of
TaNAC020-A
and
TaNAC020-B
was the favored haplotype for higher thousand kernel weight and length. Geographic distribution and allelic frequency showed that our favored haplotype experienced strong selection in China, and likewise, diversity increased in
TaNAC020s
during wheat polyploidization. The results obtained in this study demonstrate that
TaNAC020s
positively influence starch synthesis and accumulation and are one of the key regulators of the kernel (seed) size and kernel number and have the potential for utilization in wheat breeding to improve grain yield. Molecular markers developed in this study stand instrumental in marker-assisted selection for genetic improvement and germplasm enhancement in wheat.