Salt stress under the scalpel – Dissecting the genetics of salt tolerance

Salt stress limits the productivity of crops grown under saline conditions, leading to substantial yield losses in saline soils and under brackish and saline irrigation. Salt tolerant crops could alleviate these losses while both increasing irrigation opportunities and reducing agricultural demands on dwindling freshwater resources. However, despite significant efforts, progress towards this goal has been limited, largely because of genetic complexity of salt tolerance for agronomically important yield-related traits. Consequently, the focus is shifting to studying traits that contribute to overall tolerance, thus dissecting salt tolerance into components that are more genetically tractable. Greater consideration for the plasticity of salt tolerance mechanisms throughout development and across environmental conditions furthers this dissection. The demand for more sophisticated and comprehensive methodologies is being met by parallel advances in high-throughput phenotyping and sequencing technologies that are enabling the multivariate characterisation of vast germplasm resources. Alongside steady improvements of statistical genetics models, forward genetics approaches for elucidating salt tolerance mechanisms are gaining momentum. Subsequent quantitative trait locus and gene validation has also become more accessible, most recently through advanced molecular biology and genomic analyses techniques, facilitating the translation of findings to the field. Besides fueling the improvement of established crop species, this progress also facilitates the domestication of naturally salt tolerant orphan crops. Taken together, these advances herald a promising era of discovery for research into the genetics of salt tolerance in plants.