Transcriptome Analysis Identifies Novel Genes Associated with Low-Temperature Seed Germination in Sweet Corn

Area of Science:

• Plant science
• Genetics
• Molecular biology

Background:

• Sweet corn, especially sh2 varieties, exhibits poor seed vigor at low temperatures due to high sugar and low starch content.
• Variations in low-temperature germination rates among sweet corn varieties are significant, but the underlying genetic mechanisms are not well understood.

Purpose of the Study:

• To identify genes specifically induced under low-temperature conditions that influence sweet corn germination capacity.
• To compare gene expression profiles between a cold-tolerant and a cold-sensitive sweet corn inbred line at both normal and low temperatures.

Main Methods:

• Transcriptome analysis of two inbred sweet corn lines (L282 - tolerant, L693 - sensitive) under normal and low-temperature conditions.
• Differential gene expression analysis to identify common and specific differentially expressed genes (DEGs).
• Electric conductivity measurements to assess membrane damage in relation to cold tolerance.

Main Results:

• 3926 DEGs in the tolerant line (L282) and 1404 DEGs in the sensitive line (L693) were identified at low temperatures.
• 830 common DEGs were enriched in microtubule-based processes, histone modification, and carbohydrate metabolism.
• 3096 specific DEGs in L282 were related to plasma membranes and oxygen-containing compounds, correlating with reduced membrane damage.

Conclusions:

• The study reveals distinct molecular mechanisms contributing to cold germination tolerance in sweet corn.
• Candidate genes involved in microtubule function, histone modification, carbohydrate metabolism, and plasma membrane integrity are identified for future research.
• Findings enhance understanding of sweet corn's cold stress response and provide targets for breeding improved varieties.