Puyuan Yang, Yuzhe Bai, Dongting Zhao, Jianghui Cui, Weiping Yang, Yukun Gao, Jiandong Zhang, Zhibo Wang, Meng Wang, Wei Xue & Jinhua Chang

Theoretical and Applied Genetics; Published: 21 May 2024; vol. 137; article 137

Purple leaf sheath in sorghum (Sorghum bicolor (L.) Moench)

Key message

We identified a SbPLSH1gene conferring purple leaf sheath in sorghum (Sorghum bicolor (L.) Moench) and developed a functional markerfor it.

Abstract

The purple leaf sheath of sorghum, a trait mostly related to anthocyanin deposition, is a visually distinguishable morphological marker widely used to evaluate the purity of crop hybrids. We aimed to dissect the genetic mechanism for leaf sheath color to mine the genes regulating this trait. In this study, two F₂ populations were constructed by crossing a purple leaf sheath inbred line (Gaoliangzhe) with two green leaf sheath inbred lines (BTx623 and Silimei). Based on the results of bulked-segregant analysis sequencing, bulk-segregant RNA sequencing, and map-based cloning, SbPLSH1 (Sobic.006G175700), which encodes a bHLH transcription factor on chromosome 6, was identified as the candidate gene for purple leaf sheath in sorghum. Genetic analysis demonstrated that overexpression of SbPLSH1 in Arabidopsis resulted in anthocyanin deposition and purple petiole, while two single-nucleotide polymorphism (SNP) variants on the exon 6 resulted in loss of function. Further haplotype analysis revealed that there were two missense mutations and one cis-acting element mutation in SbPLSH1, which are closely associated with leaf sheath color in sorghum. Based on the variations, a functional marker (LSC4-2) for marker-assisted selection was developed, which has a broad-spectrum capability of distinguishing leaf sheath color in natural variants. In summary, this study lays a foundation for analyzing the genetic mechanism for sorghum leaf sheath color.

See https://link.springer.com/article/10.1007/s00122-024-04623-y