Salt Tolerance Mechanisms in Sorghum Crops

Soil salinity presents a growing challenge to global agriculture, constraining water uptake, disrupting ion balance and provoking oxidative damage in crop plants. Sorghum bicolor has emerged as a resilient C4 cereal capable of sustaining growth and yield in moderately saline environments. Salt tolerance in sorghum is underpinned by a suite of interlinked mechanisms. At the root level, salt‐tolerant genotypes modify meristem organisation and reinforce cell walls through increased lignin deposition, reducing ion influx. Osmotic adjustment is achieved by accumulating compatible solutes—such as proline, soluble sugars and certain amino acids—to maintain cell turgor. Selective ion transporters and vacuolar sequestration restrict harmful sodium accumulation in shoots, preserving ionic homeostasis and safeguarding photosynthetic tissues. Concurrently, antioxidant enzyme systems, including superoxide dismutase and catalase, scavenge reactive oxygen species generated under salt stress, thereby limiting lipid peroxidation and cellular injury. Hormonal signalling networks, particularly those involving gibberellins, modulate growth responses and the expression of key regulatory genes under saline conditions. The inherent efficiency of C4 photosynthesis further protects photosystem II, sustaining carbon fixation and sucrose synthesis even when stomatal conductance is compromised. Genetic diversity across landraces and breeding lines provides a rich reservoir of adaptive traits, enabling the development of cultivars suited to salt‐affected soils worldwide.

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Salt Tolerance Mechanisms in Sorghum Crops publication trend

The graph below shows the total number of articles in salt tolerance mechanisms in sorghum crops across all publications each year (not limited to Nature Index journals).

Technical terms

Osmotic adjustment: Accumulation of compatible solutes in plant cells to preserve water uptake and turgor under osmotic stress.

Ionic homeostasis: Regulation of ion transport and sequestration to prevent toxic sodium build-up and maintain cellular function.

Reactive oxygen species (ROS): Potentially damaging molecules formed under stress that require rapid detoxification.

Antioxidant enzymes: Proteins such as superoxide dismutase and catalase that neutralise ROS and protect cellular structures.

Photosynthetic performance index (PIABS): A composite measure of photosystem II efficiency and overall photosynthetic health under stress.

References

1. Salt stress alters root meristem definition, vascular differentiation and metabolome in Sorghum bicolor (L.) genotypes. Environmental and Experimental Botany (2024).
2. Progress of Research on the Physiology and Molecular Regulation of Sorghum Growth under Salt Stress by Gibberellin. International Journal of Molecular Sciences (2023).
3. Screening for genetic variability in photosynthetic regulation provides insights into salt performance traits in forage sorghum under salt stress. BMC Plant Biology (2024).
4. Deciphering the Genetic Mechanisms of Salt Tolerance in Sorghum bicolor L.: Key Genes and SNP Associations from Comparative Transcriptomic Analyses. Plants (2023).
5. Drought and salinity stress alters ROS accumulation, water retention, and osmolyte content in sorghum plants. South African Journal of Botany (2017).
6. Photosynthetic Regulation Under Salt Stress and Salt-Tolerance Mechanism of Sweet Sorghum. Frontiers in Plant Science (2020).
7. Salt Tolerance and Na Allocation in Sorghum bicolor under Variable Soil and Water Salinity. Plants (2020).