A glimpse into the symplastic and apoplastic Cd uptake by Massai grass modulated by sulfur nutrition: Plants well-nourished with S as a strategy for phytoextraction

Author(s)

Silveira Rabelo, Flavio Henrique ^[1] ; Jordao, Luiz Tadeu ^[2] ; Lavres, Jose ^[1]

Affiliation

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Piracicaba - Brazil

^[2] Sao Paulo State Univ, Fac Agr Sci, BR-18610307 Botucatu, SP - Brazil

• Document type: Journal article
• Source: Plant Physiology and Biochemistry; v. 121, p. 48-57, DEC 2017.
• Web of Science Citations: 6

Abstract

To date, there have been no studies demonstrating the influence of sulfur (S) on the cadmium (Cd) uptake kinetics, which limits the understanding of mechanisms involved in the uptake of this element. Therefore, this study was carried out in order to quantify the contribution of symplastic and apoplastic uptakes of Cd (0.1 and 0.5 mmol L-1) by Massai grass (Panicum maximum cv. Massai) grown under low and adequate S-supply (0.1 and 1.9 mmol L-1) by measuring Cd concentration in the nutrient solution (Vm(ax), K-m, and C-min) along the plant's exposure time (108 h) and determining Cd concentration in root symplast and apoplast. The V-max, of Cd influx in Massai grass exposed to higher Cd and S concentrations was 38% higher than that plants supplied with lower S concentration. The K-m and C-min of plants exposed to the highest Cd concentration was higher than that plants subjected to the lowest Cd concentration, although values were not affected by S supply. Symplastic influx of Cd in plants subjected to the lower Cd and S concentrations was 20% higher as compared to plants supplied with the higher concentration of S, whereas the apoplastic influx of Cd was higher when there was a higher supply S, regardless of Cd concentration in the solution. This result indicates that an adequate supply of S decreases the contribution of the symplastic Cd uptake and increases the contribution of the apoplastic Cd uptake when the toxicity caused by Cd is lower. (AU)

• FAPESP's process: 15/21562-2 - Synthesis of phytochelatins and expression of genes involved in the control of oxidative stress and in the cadmium detoxification in Panicum maximum Jacq. cv. Tanzania supplied with sulfur
• Grantee: Flávio Henrique Silveira Rabêlo
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 14/18735-0 - Root apoplastic and symplastic 111Cd-uptake, oxidative stress and ultra-structural changes in Panicum maximum plants supplied with sulfur
• Grantee: José Lavres Junior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/16731-7 - Relationship between sulfur and cadmium (111Cd) detoxification mechanisms in Panicum maximum cv. Tanzania
• Grantee: Flávio Henrique Silveira Rabêlo
• Support Opportunities: Scholarships in Brazil - Doctorate