Transcriptome analysis reveals critical genes and pathways of regulating the branching architecture of Lagerstroemia Indica in response to gravity signal.

• The endodermal cells and phloem fibers play an essential role in the horizontal branch architecture. • Large numbers of differentially expressed genes (DEGs) are identified between normal condition and Gravitropic growth. • The GA biosynthesis and signal transduction, starch and sucrose metabolism, and plant MAPK signaling pathway are identify to be close associations with the branching architecture in response to gravity signal. The branching architecture, as the main category of plant architecture, has a profound impact on creating natural beauty and plant production. Also, the gravitropic responses are involved in directional growth of all plants on earth. The crape myrtle as a kind of important ornamental plants is widely applied to urban landscaping. However, the regulatory mechanism controlling the branching architecture in response of gravity signal is poorly understood in crape myrtle. To identify the putative molecular mechanism, the transcriptome sequencing of crape myrtle in gravitropic growth was performed. Paraffin section analysis displayed dominant difference in the horizontal and erect branches. Also, large numbers of differentially expressed genes (DEGs) were identified between normal condition and gravitropic growth. Based on the KEGG analysis, the DEGs were mainly enriched in GA biosynthesis and signal transduction, starch and sucrose metabolism, and plant MAPK signaling pathway. This research enhanced our molecular comprehension of branching architecture in response to gravity signal while also enabling the practical application of these insights to improved crape myrtle as a significant ornamental species. [ABSTRACT FROM AUTHOR]