Genome-wide identification of glyoxalase (PbrGLY) gene family and functional analysis of PbrGLYI-28 in response to Botryosphaeria dothidea in pear.

Background: Glyoxalase (GLY) played a role in plant resistance to stress. However, little is known about the GLY in pear.

Results: Here, a total of 57 PbrGLY genes were identified through homologous comparison and analysis of conserved structural domains, which are unevenly distributed across pear chromosomes. Phylogenetic analysis revealed that the PbrGLY family can be divided into three main subfamilies, with varying numbers of members in each. Gene and protein structure analysis showed that PbrGLY possess a different number of exons and conserved motifs, and their promoter regions contain multiple stress-responsive and hormone-responsive elements. qRT-PCR analysis found that the expression levels of PbrGLY significantly changed after in response to B. dothidea infection. The transient silencing of the PbrGLYI-28 gene increased the susceptibility and methylglyoxal content of pear to B. dothidea, and decreased GLY activity of pear. The content of H₂O₂ and O₂^- was higher in TRV2-PbrGLYI-28 leaves than that in TRV2 leaves. The antioxidant enzyme activity and pathogen resistance related gene expression was lower in TRV2-PbrGLYI-28 leaves than that in TRV2 leaves.

Conclusion: This study speculates that the PbrGLY family may functionally differentiate and coordinately regulate pear resistance to ring rot disease, with the expression changes of PbrGLYI-28 potentially associated with B. dothidea infection and pear resistance.