GSE195722
Molecular dissection unveiling dwarfing effects of plant growth retardants on pomegranate
Dwarfed stature is a desired trait for modern orchard production systems. One effective strategy of dwarfing is exogenously applying plant growth retardants (PGRs) to plants. However, for many economic fruit trees, the current knowledge on the regulatory mechanisms underlying the dwarfing effect of PGRs were limited, which largely restricts their agricultural application. In this study, we exogenously applied three kinds of PGRs (paclobutrazol, B9 and mannitol) to the seedlings of pomegranate (Punica granatum L.) and performed comparative transcriptome analysis to elucidate the molecular features of PGR-induced dwarfing in pomegranates. Our results showed that all the three PGRs could significantly suppress auxin biosynthetic and metabolic processes, as well as auxin-mediated shoot development, which may be the main reason for the dwarfing. Besides, different PGRs were also found to induce dwarfing via specially mechanisms. Cellular response to strigolactone were downregulated by the application of paclobutrazol, while carbohydrate homeostasis and metabolism were specifically suppressed in conditions of either B9 or mannitol treatments. Furthermore, exogenous PGR application was supposed to causes adverse impacts on the normal physiological process of pomegranate seedlings, which may bring extra burden to stress adaptation of pomegranate plants. These novel findings unveiled the genetic basis underlying the dwarfing in pomegranates. Overall design: To investigate the molecular mechanisms underlying plant growth retardants (PGRs)-induced dwarfing in pomegranates, we exogenously applied three kinds of PGRs (paclobutrazol, B9 and mannitol) to the seedlings of pomegranate for 90 days and conducted transcriptome-wide bulk RNA-seq of the treated and untreated pomegranate plants.