Comparative transcriptome analysis of the peanut semi-dwarf mutant 1 reveals regulatory mechanism involved in plant height

Plant height is a fundamentally crucial agronomic trait to control crop growth and high yield cultivation. Several studies have been conducted on the understanding of molecular genetic bases of plant height in model plants and crops. However, the molecular mechanism underlying peanut plant height development is still uncertain. In the present study, we created a peanut mutant library by fast neutron irradiation using peanut variety SH13 and identified a semi-dwarf mutant 1 (sdm1). At 84 DAP (days after planting), the main stem of sdm1 was only about 62% of SH13. The internode length of sdm1 hydroponic seedlings was found significantly shorter than that of SH13 at 14 DAP. In addition, the foliar spraying of exogenous IAA could partially restore the semi-dwarf phenotype of sdm1. Transcriptome data indicated that the differentially expressed genes (DEGs) between sdm1 and SH13 significantly enriched in diterpenoid biosynthesis, alpha-linolenic acid metabolism, brassinosteroid biosynthesis, tryptophan metabolism and plant hormone signal transduction. The expression trend of most of the genes involved in IAA and JA pathway showed significantly down- and up- regulation, which may be one of the key factors of the sdm1 semi-dwarf phenotype. Moreover, several transcription factors and cell wall related genes were expressed differentially between sdm1 and SH13. Conclusively, this research work not only provided important clues to unveil the molecular mechanism of peanut plant height regulation, but also presented basic materials for breeding peanut cultivars with ideal plant height.

Automated summary

This study generated a peanut mutant sdm1 through fast neutron irradiation, and identified significant differences in the structure and hormone pathways between sdm1 and the conventional variety SH13. This finding is crucial for uncovering the molecular mechanism of peanut plant height regulation.