Physiological and de novo transcriptome analysis of the fermentation mechanism of Cerasus sachalinensis roots in response to short-term waterlogging.

BACKGROUND: Cerasus sachalinensis is widely used in cool regions as a sweet cherry rootstock and is known for its sensitivity to soil waterlogging and waterlogging stress. However, the limited availability of Cerasus genomic resources has considerably restricted the exploration of its waterlogging response mechanism. To understand its reaction to short-term waterlogging, we analyzed the physiology and transcriptomes of C. sachalinensis roots in response to different waterlogging durations. RESULTS: In this study, 12,487 differentially expressed genes (DEGs) were identified from Cerasus sachalinensis roots under different waterlogging durations. Carbon metabolism and energy maintenance formed the first coping mechanism stage of C. sachalinensis in response to low oxygen conditions. Root energy processes, including root respiration and activities of the fermentation enzymes alcohol dehydrogenase, pyruvate decarboxylase, and lactate dehydrogenase, showed unique changes after 0 h, 3 h, 6 h, and 24 h of waterlogging exposure. Ribonucleic acid sequencing was used to analyze transcriptome changes in C. sachalinensis roots treated with 3 h, 6 h, and 24 h of waterlogging stress. After de novo assembly, 597,474 unigenes were recognized, of which 355,350 (59.47%) were annotated. To identify the most important pathways represented by DEGs, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases were used to compare these genes. The first stage of root reaction to waterlogging stress was activation of carbohydrate metabolism to produce more glucose and maintain energy levels. At 3 h, the glycolytic and fermentation pathways were activated to maintain adenosine triphosphate production. At 24 h, pathways involved in the translation of proteins were activated to further assist the plant in tolerating waterlogging stress. These findings will facilitate a further understanding of the potential mechanisms of plant responses to waterlogging at physiological and transcriptome levels. CONCLUSIONS: Carbon metabolism and energy maintenance formed the first coping mechanism C. sachalinensis in response to low oxygen conditions, and they may be responsible for its short-term waterlogging response. Our study not only provides the assessment of genomic resources of Cerasus but also paves the way for probing the metabolic and molecular mechanisms underlying the short-term waterlogging response in C. sachalinensis.