Physiological and transcriptomic profiles of tobacco seedling leaves in response to high chloride accumulation

Abstract

Tobacco is a special commercial crop that prefers potassium but not chlorine, and excessive chloride (Cl–) accumulation can cause toxicity. Here, we revealed that the structural characteristics of chloroplasts in tobacco leaves were significantly destroyed under high Cl– salinity, but not mitochondria. Large differences in leaf structure, MDA content, and antioxidant enzyme activities were observed for the treatment with highest chloride accumulation at the 14th day. Moreover, RNA-seq analysis of tobacco leaves exposed to high Cl– salinity revealed global changes in gene transcription levels. A total of 1360 DEGs involved in cell wall, lipid, starch, and secondary metabolism processes were unevenly distributed on chromosomes, and were mainly enriched for starch and sucrose metabolism, phenylpropanoid biosynthesis, ribosome and ribosome biogenesis, protein processing in the endoplasmic reticulum, and plant hormone signal transduction pathways. Overall, our study provides valuable insights for further research on the mechanism underlying Cl– salinity and salt-tolerant tobacco development.

Keywords

• Tobacco
• leaf
• chloride salinity
• chloroplast
• antioxidant enzyme
• transcriptome