Researchers Decipher the Transcriptional Regulatory Network of Wheat Endosperm Development for Breeding Improvements

Improving yield and quality are central goals of wheat breeding. The endosperm is the main nutrient storage organ of wheat grain and the primary source of flour. Seed storage proteins (SSP) and starch are the main components of the endosperm, and their balance directly affects grain yield and end-use quality. Regulating endosperm development is an important strategy for increasing crop yield and quality, as well as addressing the trade-off between yield and quality.

 

In a recent study led by Professor XIAO Jun from the Institute of Genetics and Developmental Biology, a new discovery was made in elucidating the transcriptional regulatory network during wheat endosperm development and identifying key regulatory factors impacting this process. Published in Advanced Science, the research titled "Deciphering the Transcriptional Regulatory Network Governing Starch and Storage Protein Biosynthesis in Wheat for Breeding Improvement" (https://doi.org/10.1002/advs.202401383) unraveled the molecular and epigenetic regulation of SSP and starch formation.

 

By integrating transcriptome data, chromatin accessibility, and various histone modification sequencing at eight key developmental stages, the dynamic transcriptional and epigenetic modification landscape of wheat endosperm development was mapped. The epigenetic regulatory regions were found to be significant for driving the expression regulation of SSP and starch genes and for shaping the diversity of grain weight and quality phenotypes within wheat populations.

 

A hierarchical transcriptional regulatory network was constructed, identifying 436 core regulatory factors, including a set of transcription factors that synergistically or antagonistically regulate the expression of SSP and starch synthesis genes. A comprehensive evaluation of novel genes was conducted, screening 42 reliable candidate genes for regulating storage protein and starch synthesis, supported by GWAS signal, expression-phenotype correlations, and morphological defects of TILLING mutants.

 

Among these, TaABI3-A1 negatively regulates starch biosynthesis while activating storage protein accumulation, and it has been selected during the wheat breeding process in China as a key factor potentially balancing wheat yield and quality.

 

This study elucidated the epigenetic and molecular regulatory mechanisms of the coordinating SSP and starch synthesis in wheat grains, providing essential gene resources and selection targets for breeding high-yielding and good end-use quality wheat varieties.

 

 

 

Contact:

Dr. XIAO Jun

Institute of Genetics and Developmental Biology, Chinese Academy of Sciences

Email: jxiao@genetics.ac.cn