Identification and Functional Validation of the PeDHN Gene Family in Moso Bamboo

As climate change intensifies soil drought and salinization, enhancing the drought and salt tolerance of moso bamboo (<i>Phyllostachys edulis</i>) is urgent. DHN genes are crucial for plant stress responses and have gained attention in plant resistance to drought and salinity. This study identified nine DHN family members (<i>PeDHN1</i>-<i>PeDHN9</i>) from moso bamboo, which were classified into K₂S-type, YK₂S-type, and Y₂K₂S-type dehydrins based on their characteristic motifs. We employed integrated bioinformatics approaches to analyze their gene structure, phylogeny, biological properties, and expression patterns under various stress conditions. Five genes <i>(PeDHN2/4/5/6/8</i>), which may have significant functional roles in moso bamboo, were selected for cloning. Subcellular localization experiments showed that YK₂S-type dehydrins (PeDHN2/5/6) localized to both the nucleus and the plasma membrane, while K₂S-type dehydrins (<i>PeDHN4</i>/8) were exclusively localized to the plasma membrane, indicating functional differentiation. qRT-PCR analysis revealed that the expression of <i>PeDHN2/4/5/6/8</i> was significantly responsive to stress treatments with ABA, NaCl, and PEG. Additionally, overexpressing these genes in rice significantly enhanced seed germination rates and root development under salt and ABA stress, further confirming that PeDHN2/4/5/6/8 contribute to enhancing plant stress tolerance. Yeast one-hybrid assays demonstrated that two <i>PeABF1</i> proteins could bind to the promoter of <i>PeDHN4</i>, suggesting that <i>PeDHN4</i> may regulate stress responses through the ABA signaling pathway. Thus, these findings demonstrate that PeDHN2/4/5/6/8 are closely related to the response of moso bamboo to drought and saline-alkali environments. This research offers insights for moso bamboo cultivation and theoretical foundations for bamboo genetic improvement in stress environments.