Integrative analysis of exogenous auxin mediated plant height regulation
in moso bamboo ( Phyllostachys edulis )
Auxin is important in regulating bamboo growth and development.
Naturally grown moso bamboo shoots were treated with auxin, and changes
in endogenous hormones were determined by a selective
response/multi-response monitoring–targeted metabolomics approach.
Gibberellin and cytokinin were significantly upregulated, while auxin
inhibitor treatment also resulted in endogenous hormone disruption.
Transcriptome sequencing using Oxford Nanopore Technology revealed that
the regulation of internode length by auxin is mainly through three
pathways at the transcriptional, translational and post-translational
levels. The pathways are phytohormone signaling, amino acid synthesis
and protein processing, and energy metabolism. The transcription factors
that play major regulatory roles include ethylene response factor, WRKY
and MYB transcription factor, NAC structural domain protein and basic
leucine zipper protein. A gene regulatory network was constructed and
screened, and we cloned the core regulatory gene— PheAUX/IAA34.
We found that there may be crosstalk between auxin signaling and
jasmonic acid signaling, and verified that auxin can co-regulate growth
with plant hormones by transgenic and yeast two-hybrid experiments. The
results demonstrated that auxin-mediated height regulation in bamboo
mainly regulates internode length rather than node numbers. For single
internodes, auxin mainly regulates internode elongation by promoting
cell elongation. High-quality bamboo internode materials for production
can be obtained by auxin treatment, which can provide a reference for
bamboo plant height regulation research.