Exogenous plant growth regulator and foliar fertilizers for phytoextraction of cadmium with Boehmeria nivea [L.] Gaudich from contaminated field soil.

Abstract

(1) Background: As a enrichment plant, ramie can be used for the phytoremediation of cadmium (Cd)-contaminated soil. However, it is worth exploring the role of plant growth regulators and foliar fertilizers in the process of plant growth and development and Cd adsorption. (2) Methods: By measuring the agronomic traits, Cd content of aboveground and underground ramie, calculating the Cd transfer coefficient (TF) and Cd bioconcentration factors (BCF), and the correlation between various indicators. This study examined the effects of plant growth regulators and foliar fertilizers on ramie’s capacity for Cd accumulation and transportation, (3) Results: Plant growth regulators and foliar fertilizers increased the Cd content of the aboveground ramie, reduced the Cd content of the underground ramie, and increased the TF. Among them, GA-1 increased the Cd content of the aboveground ramie to 3 times more than that of the control and reduced the Cd content of the underground ramie by 54.76%. Salicylic acid (SA) increased the Cd content of the aboveground ramie to 3 times more than that of the control. The combination of GA and foliar fertilizer reduced the Cd content of the aboveground and underground ramie and the TF and BCF of the underground ramie. After the hormones were sprayed, the TF of ramie had a significant positive correlation with the Cd content of the aboveground ramie; the BCF of the aboveground ramie had a significant positive correlation with the Cd content and TF of the aboveground ramie. (4) Conclusions: The results indicate that Brassinolide (BR), gibberellin (GA), ethephon (ETH), polyamines (PAs), and salicylic acid (SA) have different effects on the enrichment and transport of Cd in ramie. This study provided an effective method to improve the capacity for ramie to adsorb heavy metals during cultivation.

A Systematic Review on the Improvement of Cd Stress Tolerance in Ramie Crop, Limitations and Future Prospective

“…Directly adding ABA to the cultural solution promoted ramie growth and development under Cd stress, increased Cd enrichment, and indicated its regulatory role in enhancement or stress tolerance and as a potential agronomic agent [73]. Similarly, another research team led by He et al [74] studied the effect of different growth regulators on the Cd content in ramie. The results showed that a foliar spray of hormones reduced the Cd content in underground parts of ramie, which showed the potential role of these growth regulators in increasing Cd tolerance [74].…”

“…Similarly, another research team led by He et al [74] studied the effect of different growth regulators on the Cd content in ramie. The results showed that a foliar spray of hormones reduced the Cd content in underground parts of ramie, which showed the potential role of these growth regulators in increasing Cd tolerance [74].…”

“…The results indicated that GA-1 enhanced the Cd content of the aboveground ramie to three times more than that of the control and decreased the Cd content of the underground ramie by 54.76%. This research study offers an effective technique to advance the capability of ramie to adsorb heavy metals [74].…”