Genome-enabled phosphorus acquisition strategy drives the rapid reproduction of water hyacinth (Pontederia crassipes) leading to global invasion

The global expansion of water hyacinth (Pontederia crassipes) endangers water ecological security and high-quality economic development; moreover, its invasion mechanism at the genomic and molecular levels remains unclear. Here, a high-quality, chromosome-level genome of water hyacinth (1.25 Gb; N50 = 80.91 Mb) was assembled for the first time. Of the 59,361 genes, 64,988 transcripts were annotated using transcriptome data from five distinct water hyacinth tissues. Compared to the allied species Pontederia cordata, one more whole-genome duplication event occurred approximately 4 Mya. Gene families related to P metabolic pathways have significantly expanded during evolution. Nine of the twenty-two differentially expressed genes between stolons and other tissues were involved in P metabolism, including four genes that encode purple acid phosphatases (PAPs). Under 2.0 P, water hyacinth ramets exhibited a 1.4-fold increase compared to those under 1.0 P during the 40-day culture. Acid phosphatase content in roots significantly increased from 219.42 ± 78.10 U/g under P deficiency stress to 44.89 ± 15.23 U/g under P-sufficient water (p < 0.05). Organic P can restore water hyacinth growth under P deficiency. Subcellular localisation showed that PcPAP19 and PcPAP53 were located in the cell membrane. Thus, PcPAPs play a key role in P regulation during water hyacinth growth. These findings demonstrate how the assembled genome advances understanding of the molecular mechanism underlying P-use efficiency and proliferation in plants.