Alternative splicing analysis of stress tolerance to Al and flg22 in Vitis quinquangularis.

Main conclusion: Alternative splicing of transcriptomes after Al and flg22 treatment for 12 h in response to plant defense of Chinese wild Vitis quinquangularis: genes related to stress resistance and splicing factors were identified in response to Al and flg22 treatment. Alternative splicing (AS) is one of the major post-transcriptional regulation processes that potentially regulates the response to biotic and abiotic stresses in plants. So far, the insight into potential roles of AS in grapevine response to aluminium (Al) and flagellin 22 (flg22) stresses remains poorly understood. We performed transcriptome sequencing of grape leaves before and after Al treatment and flg22 treatment, respectively, to identify AS genes. In this study, a total of 11,805 AS events were identified in Al treatment, of which the skipped exon (SE; 88.72%) type was the most frequent. 9156 AS events were identified under flg22 treatment, of which the SE (88.52%) type was the most frequent. Compared with Al-treated and flg22-treated 0 h, there were 42 and 147 differential alternative splicing (DAS) genes differentially expressed (DASEGs) in Al-treated and flg22-treated 12 h, respectively. Functional analysis showed that DASEGs after Al treatment were mainly enriched in glutathione metabolism pathway; DASEGs after flg22 treatment were enriched in MAPK signaling and plant hormone signal transduction. We further verified seven resistance-related DASEGs with up-regulated expression in Al-treated 12 h, including beta-glucosidase, calcineurin B-like protein, synaptotagmin-3, cysteine synthase and glutathione reductase. Several genes function as leucine-rich repeats receptor-like serine/threonine protein kinase, BRI1 associated receptor kinase 1 and receptor-like protein kinase were also verified by RT-qPCR. We also verified four serine/arginine (SR)-rich proteins SCL30A, SCL28, RS2Z32 and SR45A, which were up-regulated in both Al and flg22 stresses. In conclusion, this study provides an in-depth analysis of the correlation between alternative splicing and grapevine stress tolerance, which helps to identify potential candidate genes for useful traits, provides a theoretical basis for grapevine breeding in plant stress tolerance, and offers new perspectives for understanding grapevine environmental adaptation strategies.