Chromosomal-level genome and metabolome analyses of highly heterozygous allohexaploid Dendrocalamus brandisii elucidate shoot quality and developmental characteristics.

Abstract

Dendrocalamus brandisii (Munro) Kurz is a sympodial bamboo species with inimitable taste and flavorful shoots. Its rapid growth and use as high-quality material make this bamboo species highly valued for both food processing and wood applications. However, genome information for D. brandisii is lacking, primarily due to its polyploidy and large genome size. Here, we assembled a high-quality genome for hexaploid D. brandisii, which comprises 70 chromosomes with a total size of 2,756 Mb, using long-read HiFi sequencing. Furthermore, we accurately separated the genome into its three constituent subgenomes. We used Oxford Nanopore Technologies long reads to construct a transcriptomic dataset covering 15 tissues for gene annotation to complement our genome assembly, revealing differential gene expression and post-transcriptional regulation. By integrating metabolome analysis, we unveiled that well-balanced lignin formation, as well as abundant flavonoid and fructose contents, contribute to the superior quality of D. brandisii shoots. Integrating genomic, transcriptomic, and metabolomic datasets provided a solid foundation for enhancing bamboo shoot quality and developing efficient gene-editing techniques. This study should facilitate research on D. brandisii and enhance its use as a food source and wood material by providing crucial genomic resources.