Transcriptome analysis of taro（Colocasia esculenta）leaves under drought stress

【Objective】 This study aimed to clarify the key pathways and related genes of taro leaves in response to drought stress，analyze the gene expression patterns under drought conditions，and explore the molecular response mechanisms. The findings would provide theoretical references for understanding the molecular mechanisms of taro’s drought regulation and for breeding different drought tolerant taro varieties in the future. 【Method】 Using Lipu taro as the experimental material，leaf samples were collected after consecutive 7 d of drought treatment as the treatment group，while leaf samples from plants watered daily served as the control group. Transcriptome sequencing was performed to identify differentially expressed genes，which were then subjected to GO functional annotation and KEGG pathway enrichment analysis. 【Result】 Under drought stress，there were 1613 differentially expressed genes（DEGs），including 1043 up-regulated and 570 down-regulated genes. GO functional annotation analysis revealed that the DEGs were categorized into three major functional groups：molecular function，cellular component，and biological process. In the molecular function category，DEGs were annotated to binding and catalytic activity. In the cellular component category，DEGs were annotated to cellular anatomical entities and protein-containing complexes. In the biological process category，DEGs were annotated to cellular processes and metabolic processes. KEGG signaling pathway enrichment analysis showed that 85.00% of the DEGs were enriched in metabolic pathway. Among these，the DEGs were primarily enriched in the glutathione metabolism pathway and the starch and sucrose metabolism pathway，with 11 and 19 DEGs identified in each pathway respectively. Under drought stress，a total of 112 differentially expressed transcription factors （TFs） were identified， mainly including members of the bHLH，ERF，WRKY and NAC families. Among all differentially expressed TFs， 82.14% showed up-regulated transcription levels under drought conditions. Plant hormone signal transduction，carotenoid biosynthesis，and the MAPK signaling pathway-plant were identified as key abscisic acid-responsive pathways involved in drought response，influencing stomatal closure in taro leaves and seed dormancy to cope with drought stress. The relia-bility of the transcriptome data was confirmed by quantitative real-time PCR analysis. 【Conclusion】 Under drought stress， the gene expression in the glutathione metabolism pathway，the starch and sucrose metabolism pathway，and transcription factors in taro leaves is affected. Most TFs are positively involved in regulating taro plant’s drought response.