Water supply is essential for maintaining normal physiological function during the rapid growth of bamboo. Aquaporins (AQPs) play crucial roles in water transport for plant growth and development. Although 26 PeAQPs in bamboo have been reported, the aquaporin-led mechanism of maintaining diurnal water balance in bamboo shoots remains unclear. In this study, a total of 63 PeAQPs were identified, based on the updated genome of moso bamboo (Phyllostachys edulis), including 22 PePIPs, 20 PeTIPs, 17 PeNIPs, and 4 PeSIPs. All of the PeAQPs were differently expressed in 26 different tissues of moso bamboo, based on RNA sequencing (RNA-seq) data. The root pressure in shoots showed circadian rhythm changes, with positive values at night and negative values in the daytime. The quantitative real-time PCR (qRT-PCR) result showed that 25 PeAQPs were detected in the base part of the shoots, and most of them demonstrated diurnal rhythm changes. The expression levels of some PeAQPs were significantly correlated with the root pressure. Of the 86 sugar transport genes, 33 had positive co-expression relationships with 27 PeAQPs. Two root pressure-correlated PeAQPs, PeTIP4;1 and PeTIP4;2, were confirmed to be highly expressed in the parenchyma and epidermal cells of bamboo culm, and in the epidermis, pith, and primary xylem of bamboo roots by in situ hybridization. The authors’ findings provide new insights and a possible aquaporin-led mechanism for bamboo fast growth.

Buchloe dactyloides is one of the typical ecological grass species, characterized by its strong salt tolerance. Hexokinase (HXK) plays a crucial role in plant growth, development, and resistance to abiotic stresses. To understand the function of HXKs in the salt tolerance of B. dactyloides, this study identified and analyzed the HXK gene family members using the whole-genome data of B. dactyloides. Additionally, transcriptomic methods were employed to investigate the expression levels and stress response patterns of the HXK family genes under salt stress. The results showed that 25 HXK genes were identified in the B. dactyloides HXK gene family, which were classified into three subfamilies based on the phylogenetic tree. Members within the same subfamily exhibited similar gene structures and conserved motifs. The promoter regions of BdHXKs contained numerous cis-regulatory elements associated with plant hormone responses, plant growth and development, and resistance to abiotic stresses. Quantitative real-time PCR analysis provided preliminary evidence that the BdHXK5, BdHXK7, and BdHXK23 genes might play important roles in the salt tolerance regulation of B. dactyloides. These findings offer a theoretical foundation for further elucidating the functions and molecular regulatory mechanisms of BdHXKs under salt stress. This study has provided a theoretical basis for the breeding of new varieties of ecological restoration grasses with stronger salt tolerance and better growth and development. This is of great significance for the improvement and ecological restoration of saline–alkali land.