Transcriptome analysis of peach seedlings (Prunus davidiana) experiencing drought stress.

Abstract

The frequency of drought is expected to rise in many parts of the world with increasing climate change. Despite being an economically valuable plant species, the molecular mechanisms regulating the responses of peach (Prunus davidiana) to drought stress and the functional genes conferring drought resistance are currently unknown. In this study, we investigated the phenotypic and physiological responses of peach seedlings to experimental conditions that included a control, a period of drought stress, and a rehydration period. We performed transcriptome sequencing and investigated differences in the transcriptome of peach seedlings exposed to different treatments. We also analyzed the functions and regulatory pathways of differentially expressed genes using GO and KEGG enrichment. The results showed that severe drought stress occurred in the peach seedlings on the sixth day of drought, and that the physiological responses of peach seedlings experiencing drought stress were significantly different from those in control conditions. We found 21348 differentially expressed genes in peach seedlings under drought stress, of which 10105 were up-regulated and 11243 were down-regulated in comparison with peach seedlings in control conditions. These differentially expressed genes were mainly involved in the biosynthesis of amino acids, metabolic pathways, antioxidant defense systems and the plant hormone signal transduction system. The results suggest that peach seedlings respond to severe drought stress by initiating antioxidant defense mechanisms to alleviate damages, activating different signal transduction pathways to transmit signals, regulating the synthesis of amino acids, and initiating metabolic mechanisms to enhance osmotic pressure. This study illuminates the mechanisms for drought resistance in peach seedlings at the molecular level. Overall, the findings provide a theoretical basis for the cloning and functional analysis of genes conferring drought resistance, and the cultivation of more drought resistant varieties of peach.