Comparative physiological and transcriptomic analysis reveals salinity tolerance mechanisms in Sorghum bicolor (L.)...

Area of Science:

• Plant Science
• Genetics
• Agronomy

Background:

• High soil salinity poses a significant threat to global crop production.
• Understanding crop salinity tolerance mechanisms is crucial for developing resilient crop varieties.
• Sorghum landraces may possess valuable genetic resources for improving crop salinity tolerance.

Purpose of the Study:

• To identify and compare the physiological and molecular mechanisms of salinity tolerance in the sorghum landrace Mota Maradi against a reference line.
• To investigate the genetic basis of enhanced salinity tolerance in Mota Maradi.
• To explore the potential of Mota Maradi as a donor for breeding salinity-tolerant sorghum.

Main Methods:

• Comparative physiological analysis of Mota Maradi and BTx623 under salinity stress.
• Transcriptome profiling of various sorghum tissues (leaves, leaf sheaths, stems, roots).
• Differential gene expression analysis and functional/pathway analysis of identified genes.

Main Results:

• Mota Maradi exhibited superior physiological performance, including growth, biomass gain, and photosynthetic rate, compared to BTx623.
• Significant differences in Na+, K+, proline, and sucrose accumulation were observed between the two lines.
• Transcriptome analysis revealed contrasting differentially expressed genes (DEGs) related to ion transport (e.g., HKT, NHX), photosynthesis, growth, signaling, and ROS scavenging.

Conclusions:

• Mota Maradi possesses holistic salinity tolerance mechanisms, involving synergistic regulation of ion homeostasis, photosynthesis, and cellular processes.
• Specific ion transporters and metabolic pathways are key contributors to Mota Maradi's salinity tolerance.
• This landrace is a promising genetic resource for breeding improved, salinity-tolerant sorghum varieties.