Spatio-temporal transcriptome profiling and subgenome analysis in Brassica napus

Area of Science:

• Plant Biology
• Genomics
• Molecular Biology

Background:

• Brassica napus, an important oil crop, is an allotetraploid species.
• Detailed analysis of gene function and homoeologous gene expression across all tissues and developmental stages remains unexplored.

Purpose of the Study:

• To perform a global transcriptome analysis of Brassica napus.
• To identify tissue-preferred genes (TPGs) and hub genes.
• To explore homoeologous gene expression patterns and their relationship with regulatory elements.

Main Methods:

• Global transcriptome analysis of 24 vegetative and reproductive tissues across six developmental stages (111 tissues total).
• Clustering of samples into eight groups.
• Co-expression network analysis.
• Analysis of transposable elements (TEs) and regulatory elements (REs) in relation to homoeolog expression.

Main Results:

• Gene functions in silique pericarp showed similarity to roots, stems, and leaves, with glucosinolate metabolism linked to root and silique pericarp.
• Protein phosphorylation genes were associated with stamen, anther, and early seed development.
• Identified 17,100 tissue-preferred genes (TPGs), including 889 transcription factors (TFs).
• Approximately 67.0% of homoeologs exhibited balanced expression; biased expression correlated with structural divergence.
• Spatiotemporal homoeolog expression was linked to TEs and REs, with more TEs and fewer REs in promoters leading to divergent expression.

Conclusions:

• This study provides a valuable transcriptional map for Brassica napus growth and development.
• Identified important genes for future crop improvement.
• Offers insights into gene expression patterns and homoeolog regulation in Brassica napus.