Transcriptome Changes Between the Heat-Tolerant and Heat-Sensitive Rice (Oryza sativa L.) in Response to High Night Temperature Stress

Rice yield and quality are adversely affected by high temperatures, especially at night which is more harmful to grain weight in rice than high daytime temperatures. Unfortunately, the global temperature is consistently rising and thus the minimum temperature at night time has increased almost three times as much as the corresponding maximum daytime temperature over the past decades. In present study, we analyzed the transcriptome profiles for rice grain from the heat-tolerant and -sensitive lines in response to high night temperatures at the early milky stage by Illumina Sequencing method. The analysis results for sequencing data showed that 35 transcripts showed different expression between the heat-tolerant and -sensitive rice. Function analysis of the differentially expressed transcripts indicated that 21 genes have functional annotation and their functions are mainly involved in oxidation-reduction process (6 genes), metabolic process (7 genes), transport process (4 genes), transcript regulation process (2 genes), defense response process (1 gene) and photosynthesis process (1 gene). According to the functional annotation of the differentially expressed genes, the possible process showed that high night temperature stress disrupts electron transport in the mitochondria, which leads to changes in the concentration of hydrogen ions in the mitochondrial and cellular matrix and influences the activity of enzymes involved in TCA and its secondary metabolism in plant cells. The model proposed here is based on differences in expression and transcription between two rice lines. It may support future studies on the molecular mechanisms underlying plant high night temperature responses.

Keywords: rice; early milky stage; high night temperature; transcriptomics; RNA-sequencing

Corresponding author: Yingjin Huang