Genomic Insights into Seed Germination Differences in Buffalobur (Solanum rostratum Dunal) under Contrasting GA and ABA Availability

Abstract

Buffalobur (Solanum rostratum Dunal) is an invasive species that seriously endangers crop production and the ecological environment. Seeds are the primary source of infestation; therefore, understanding the molecular basis of buffalobur seed dormancy, and germination is crucial for precision weed management. In this study, high-throughput RNA-Seq was performed on buffalobur seeds, which imbibed under 0.35 mmol/L giberellic acid (GA) and 0.35 mmol/L abscisic acid (ABA). In total, 3658 differentially expressed genes (DEGs) were identified during seed germination. Gene annotation revealed that the DEGs were significantly enriched during the protein metabolic process, as well as the macromolecular complex and cytoplasmic part for ABA versus GA. Pathway analysis predicted that the DEGs were associated with metabolic pathways, the biosynthesis of secondary metabolites and ribosome. Nine germination-related genes involved in the biosynthesis and metabolism of the phytohormones and encoding of the endo-β-mannanase (EBM) were identified. Gene expression indicated that GA upregulated GA3OX1 and MAN2 expression to increase the EBM activity, which caused the endosperm cap to weaken and lowered the puncture force to trigger the germination of buffalobur. The obtained results would be helpful to clarify the regulation of seed dormancy and the germination of buffalobur, and could serve as a valuable resource when unravelling the genetic basis of seed biology of this weed species.