Chickpea sulfate transporters vary in response to sulfur starvation

A comparative study of chickpea seedlings found that cultivars PUSA256 and PUSA1003 maintained better growth, more favorable root architecture, greater sulfur-assimilation enzyme activity and stronger SULTR gene expression under sulfur starvation than cultivar PUSA3022. The research also identified 15 members of the chickpea sulfate-transporter gene family, providing a genome-wide framework for examining how different cultivars respond when sulfate is unavailable in the growth medium.

The investigation focused on Cicer arietinum L., a major pulse crop whose protein quality is limited in part by low levels of sulfur-containing amino acids. Sulfur deficiency in agricultural soils makes improvements in sulfate uptake and assimilation relevant to efforts to increase the nutritional quality of chickpea. The study addressed the limited understanding of the molecular complexity and cultivar-specific roles of plant sulfate transporters in legumes through a combination of genome-wide analyses, computational expression predictions and comparative physiological measurements.

Genome-wide, phylogenetic, duplication and synteny analyses identified 15 CaSULTR genes, named CaSULTR1 through CaSULTR15. The encoded proteins contained the conserved Sulfate_transp and STAS domains. The genes were divided into four groups based on the combined analyses, and their expansion was attributed primarily to dispersed and whole-genome duplication. The researchers also detected purifying selection among retained genes, indicating that functional constraints have acted on the expanded family. These findings characterize the organization and evolutionary history of the CaSULTR gene set but do not independently establish the transport activity of individual genes.

Promoter analysis identified cis-regulatory elements associated with stress, hormone, growth-and-development, and light-related responses, suggesting that CaSULTR expression may be influenced by multiple regulatory signals. Computational expression analysis also predicted tissue-specific patterns. CaSULTR2 was highly induced in roots, while CaSULTR8 displayed a shoot-specific expression profile. Because these patterns were inferred in silico, they identify candidate genes and regulatory features for further investigation rather than directly measuring transporter activity, protein abundance or cellular localization.

For the physiological comparison, the researchers grew seedlings under sulfur-sufficient conditions, providing 2 mM sulfate, and sulfur-starvation conditions, providing 0 mM sulfate. Under starvation, PUSA256 and PUSA1003 exhibited improved biomass and root architecture, increased activities of the sulfur-assimilation enzymes SERAT and OASTL, and elevated SULTR gene expression. PUSA3022 showed poor growth and a comparatively weak transcriptional response. These observations associate a stronger sulfate-transport and sulfur-assimilation response with better performance under sulfate deprivation, but the reported comparison does not demonstrate that any individual CaSULTR gene caused the observed cultivar differences. Overall, the results identify the CaSULTR family, SERAT and OASTL activity, and root-related physiological traits as potential leads for breeding programs seeking improved sulfate-use efficiency in chickpea.

Subject of Research: Genome-wide characterization of chickpea sulfate transporters and cultivar responses to sulfur starvation

Article Title: Genome-wide characterization and expression analysis of the SULTR gene family in Cicer arietinum: regulates the sulfate transport/assimilation under sulfur starvation

Article References: Nagesh, C. R., Dutta, M., Gadpayale, D. P., Sushmitha, J., Dineshkumar, R., Bansal, N., Mallikarjuna, M. G., Goswami, S., Kumar, R. R., Sathee, L., Pandey, R., Bharadwaj, C., Dahuja, A., Prashat, G. R., & Vinutha, T. (2026). Genome-wide characterization and expression analysis of the SULTR gene family in Cicer arietinum: regulates the sulfate transport/assimilation under sulfur starvation. BMC Plant Biology. https://doi.org/10.1186/s12870-026-09145-x

Image Credits: AI Generated

DOI: 10.1186/s12870-026-09145-x

Keywords: chickpea, sulfate transporters, SULTR genes, sulfur starvation, sulfur-use efficiency, plant genomics, root architecture, sulfur assimilation, pulse crops, gene family evolution, Genome-wide, characterization