Transcriptomic profiling revealed genes involved in response to cold stress in maize

Area of Science:

• Plant Science
• Agricultural Science
• Molecular Biology

Background:

• Maize (Zea mays) is a vital global food crop.
• Chilling stress significantly reduces maize yield by impairing germination and seedling development, particularly in early spring.
• Understanding maize cold tolerance mechanisms is crucial for agricultural productivity.

Purpose of the Study:

• To investigate the molecular and physiological differences between chilling-tolerant and chilling-sensitive maize inbred lines under cold stress.
• To identify key genes and metabolic pathways involved in maize cold tolerance.

Main Methods:

• Comparative analysis of chlorophyll fluorescence, membrane lipids, and secondary metabolites.
• Transcriptome analysis using RNA sequencing under controlled cold stress conditions (0, 4, and 24 hours).
• Evaluation of two maize inbred lines: chilling-tolerant M54 and chilling-sensitive 753F.

Main Results:

• The chilling-tolerant M54 line demonstrated superior protection of Photosystem II (PSII) and enhanced accumulation of secondary metabolites compared to 753F.
• Cold stress predominantly affected genes involved in photosynthesis, secondary metabolism, and signal transduction.
• M54 exhibited less cold-induced disruption of photosystem structure and electron transport genes, alongside stronger upregulation of secondary metabolism and unsaturated fatty acid synthesis genes.

Conclusions:

• Maize inbred line M54 achieves higher cold tolerance through effective protection of photosystems and maintenance of cell membrane stability.
• Upregulation of secondary metabolism and unsaturated fatty acid synthesis pathways contributes significantly to cold hardiness in maize.
• Transcriptomic and metabolic profiling provides insights into the complex genetic architecture of maize chilling tolerance.