Root Transcriptome Analysis Identifies Salt-Tolerance Genes in Sweet Corn Chromosome Segment Substitution Lines...

Area of Science:

• Plant Science
• Genetics
• Agronomy

Background:

• Salt stress is a major threat to global crop productivity, particularly affecting sweet corn cultivars which generally have low salt tolerance.
• Understanding the genetic and physiological mechanisms of salt tolerance is crucial for developing resilient crop varieties.

Purpose of the Study:

• To compare the physiological and transcriptomic responses of salt-tolerant (D55) and salt-sensitive (D96) sweet corn lines under salinity stress.
• To identify candidate genes and molecular pathways involved in sweet corn salt adaptation.

Main Methods:

• Comparative phenotyping and physiological profiling of sweet corn seedlings under salt treatment.
• Transcriptome analysis of root tissues at multiple time points (0, 4, 12, 72 hours) post-treatment.
• Bioinformatic analysis of differentially expressed genes (DEGs) and enrichment analysis (Gene Ontology).

Main Results:

• The salt-tolerant D55 line exhibited superior growth, higher chlorophyll content, and enhanced antioxidant enzyme activity compared to D96.
• Transcriptomic analysis revealed significant differences in gene expression between the two lines, with key genes related to reactive oxygen species (ROS) homeostasis, phenylpropanoid metabolism, and phytohormone signaling identified.
• A multi-layered salt adaptation strategy involving ROS detoxification, osmotic balance, and phytohormone signaling was proposed, with 14 candidate genes identified for salt tolerance.

Conclusions:

• The salt-tolerant sweet corn genotype D55 employs a robust defense mechanism against salt stress, involving enhanced ROS scavenging and metabolic adjustments.
• The identified candidate genes provide valuable targets for genetic engineering and breeding programs aimed at enhancing salt tolerance in sweet corn.
• This research contributes to a deeper understanding of plant adaptation to abiotic stress and offers strategies for improving crop resilience.