Genome-wide identification and gene expression analyses of GH3 gene family under abiotic stress in Phyllostachys...

The Gretchen Hagen 3 (GH3) family plays an essential role in plant growth, development and resistance to environmental stress. Although, the members in GH3 family have been reported in some monocots, their exploration in Phyllostachys edulis needs to be further explored.

In the present study, we identified totally 23 GH3 genes from P. edulis at the genomic level, which were categorized into two subfamilies (I and II) based on phylogenetic analysis. Subsequent analyses concentrated on the molecular features of these genes, including their gene structure, conserved motifs, cis-acting elements in promoters, and syntenic regions in the genome. Furthermore, qRT-PCR results indicated that most PeGH3 genes were extensively expressed across all the tested tissues. Meanwhile, some of them were also responsive to abiotic stresses such as salt and drought, as well as hormone treatments including naphthalene acetic acid (NAA) and salicylic acid (SA) based on RNA-seq data analysis. According to the tissue-specific and stress-responsive expression results, PeGH3-4, PeGH3-8, PeGH3-14, and PeGH3-18 were likely to play significant roles in plant growth and in response to abiotic stress. Subcellular localization analysis demonstrated that these four PeGH3 proteins were predominantly localized in the cytoplasm and nucleus. To further clarify their function in stress tolerance, PeGH3-4, PeGH3-8, PeGH3-14, and PeGH3-18 were expressed in yeast, which proved their ability to enhance yeast tolerance to salt and drought stresses.

This research enhances the understanding of PeGH3 genes and provides genetic resources for breeding bamboo plants with improved resistance to stress, especially to salt and drought.