This study profiled physiological, biochemical, and transcriptional responses of Solanum nigrum to cadmium (Cd) in potted soil across graded treatments. Growth, assessed as fresh and dry mass, and chlorophyll a declined only at higher doses, whereas carotenoids increased by about 70%. Proline rose by roughly 302% and soluble proteins by 173% in a dose-responsive manner, consistent with up to 9. 1-fold increases in P5CS transcripts. Malondialdehyde and hydrogen peroxide increased with Cd, accompanied by antioxidant responses. Shoots accumulated substantial Cd in soil, reaching 170 mg kg -1 DW at 100 mg kg -1 soil Cd, while the tolerance index remained ≥ 60% at the highest dose. The translocation factor exceeded one at all additions and peaked at ~ 1. 28 at 50–100 mg kg -1 Bioavailability-aware enrichment remained high: BCFₐvailable (shoot) referenced to DTPA-Cd was ~ 19. 4 at 12. 5–25 mg kg -1 16. 9 at 50 mg kg -1, and 12. 6 at 100 mg kg -1. Whole-plant removal increased monotonically, with total Cd uptake of approximately 166, 303, 392, and 518 µg plant -1 at 12. 5, 25, 50, and 100 mg kg -1, respectively. Candidate transporter transcripts showed distinct dose-dependent patterns in soil: SnYSL3 peaked at the intermediate dose (~ 7. 6-fold), whereas HMA3 rose progressively and was highest at 100 mg kg -1 (~ 7. 2-fold). Principal component analysis separated treatments and grouped stress markers with P5CS and HMA3 at higher Cd. This work provides a gradient-resolved, soil-based dataset linking Cd partitioning, bioavailability-normalized indices, and total uptake with coordinated shifts in candidate YSL and HMA transporters and key metabolites. The resulting framework establishes a standardized baseline for functional validation and field translation.
Norouzi et al. (Fri,) studied this question.