Unraveling the dataset transcriptomic response of Hydrangea macrophylla stem to mechanical stimulation: de novo assembly and functional annotation

To gain plant compactness, producers use plant growth regulators (PGRs), in particular growth retardants during culture. However, due to their negative environmental impacts, growth retardants are progressively withdrawn from the market. Alternative, eco-friendly methods such as mechanical stimulation (MS), which mimics the effect imposed on plants by the wind, result in reduced stem elongation, increased stem diameter and increased branching, all of which contribute to plant compactness. So far, few plant species were studied under MS and little is known on molecular response mechanisms to MS. This first transcriptomic data after MS in Hydrangea macrophylla cv. 'Wudu'® will contribute unravelling how plants respond to mechanical stimuli. Overall design: Mechanical stimulation (MS) of Hydrangea macrophylla stems consisted in 12 consecutive bendings applied at 9 a.m. during 1 h and for a single day. Transcriptomic data were obtained from whole stem collected 15 min before MS (T0) and 1 h, 3 h, 24 h and 72 h after 12 consecutive bendings (S group) or without bendings (NS group). There are therefore 9 different conditions, each with 3 biological replicates i.e. 27 samples. T0 and NS groups constitute the experiment's control groups.