Exogenous plant growth regulator alleviate the adverse effects of U and Cd stress in sunflower (Helianthus annuus L.) and improve the efficacy of U and Cd remediation

Chemosphere ◽  
2021 ◽  
Vol 262 ◽  
pp. 127809 ◽  
Author(s):  
Li Chen ◽  
Wei-fang Hu ◽  
Chan Long ◽  
Dan Wang
2007 ◽  
Vol 35 (2) ◽  
pp. 993-996 ◽  
Author(s):  
Sulejman Redžepović ◽  
Sanja Sikora ◽  
Josip Čolo ◽  
Mihaela Blažinkov ◽  
Marija Pecina

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ertan Yildirim ◽  
Melek Ekinci ◽  
Metin Turan ◽  
Güleray Ağar ◽  
Atilla Dursun ◽  
...  

AbstractCadmium (Cd) is a toxic and very mobile heavy metal that can be adsorbed and uptaken by plants in large quantities without any visible sign. Therefore, stabilization of Cd before uptake is crucial to the conservation of biodiversity and food safety. Owing to the high number of carboxyl and phenolic hydroxyl groups in their structure, humic substances form strong bonds with heavy metals which makes them perfect stabilizing agents. The aim of this study was to determine the effects of humic and fulvic acid (HA + FA) levels (0, 3500, 5250, and 7000 mg/L) on alleviation of Cadmium (Cd) toxicity in garden cress (Lepidium sativum) contaminated with Cd (CdSO4.8H2O) (0, 100, and 200 Cd mg/kg) under greenhouse conditions. Our results showed that, Cd stress had a negative effect on the growth of garden cress, decreased leaf fresh, leaf dry, root fresh and root dry weights, leaf relative water content (LRWC), and mineral content except for Cd, and increased the membrane permeability (MP) and enzyme (CAT, SOD and POD) activity. However, the HA + FA applications decreased the adverse effects of the Cd pollution. At 200 mg/kg Cd pollution, HA + FA application at a concentration of 7000 mg/L increased the leaf fresh, leaf dry, root fresh, root dry weights, stem diameter, leaf area, chlorophyll reading value (CRV), MP, and LRWC values by 262%, 137%, 550%,133%, 92%, 104%, 34%, 537%, and 32% respectively, compared to the control. Although the highest H2O2, MDA, proline and sucrose values were obtained at 200 mg/L Cd pollution, HA + FA application at a concentration of 7000 mg/L successfully alleviated the deleterious effects of Cd stress by decreasing H2O2, MDA, proline, and sucrose values by 66%, 68%, 70%, and 56%, respectively at 200 mg/kg Cd pollution level. HA + FA application at a concentration of 7000 mg/L successfully mitigated the negative impacts of Cd pollution by enhanced N, P, K, Ca, Mg, Fe, Mn, Cu, Mn, Zn, and B by 75%, 23%, 84%, 87%, 40%, 85%, 143%, 1%, 65%, and 115%, respectively. In addition, HA + FA application at a concentration of 7000 mg/L successfully reduced Cd uptake by 95% and Cl uptake by 80%. Considering the plant growth parameters, the best results were determined when HA + FA concentration was 7000 mg/L. We have shown that, it is critical to apply a humic substance with high percentage of FA, which was 10% in this study, to mitigate the adverse effects of heavy metal stress on plant growth. In conclusion, the application of HA + FA may be suggested as an effective solution for reducing the Cd uptake of the plants by stabilizing Cd in soil and preventing translocation of Cd from the roots of plant to its shoot and leaves.


2004 ◽  
Vol 44 (3) ◽  
pp. 343 ◽  
Author(s):  
A. C. Rath ◽  
A. J. Prentice

The effects ReTain Plant Growth Regulator (830 g in 1000 L water/ha) applied to a commercial block of 'Arctic Snow' nectarines 7 days before the first harvest was assessed in relation to harvest delay, fruit size, fruit quality (flesh firmness and brix), as well as the quality of the fruit following export to Taiwan. The untreated block (0.87 ha) and the ReTain-treated block (1.0 ha) were harvested according to the orchard's standard maturation criteria of background colour, size and percent blush colour. Based on picking schedules, the maturation of the ReTain block was delayed by 2.75 days (P<0.05). The fruit continued to grow during this delay and resulted in a 12.3% increase in yield and an increase of 393 packed cartons/ha. There were more (P<0.001) cartons of ReTain-treated fruit packed in grade sizes 69–78 mm diameter and less of smaller size classes (51–66 mm) compared with untreated fruit. The increase in both the number of cartons of class 1 fruit and fruit size on the ReTain block resulted in a Return on Investment (ROI) of 14.7 : 1 with an additional net return of AU$17 655/ha over the untreated block. There was a correlation between fruit size and flesh firmness with larger fruit being firmer than smaller fruit (P<0.001), however, packed ReTain-treated fruit was 3.2 N firmer on average (P<0.001) than packed untreated fruit for all size grades and from all harvests and packs. Brix levels increased (P<0.001) with fruit size but there was no difference (P = 0.568) between ReTain-treated fruit and untreated fruit. Two containers of fruit (early and late picks) were exported to Taiwan. The containers held a temperature of 0.5–2.0°C for the 14–15 day transit time from Australia to Taiwan. ReTain-treated fruit in both containers was 1.7 N firmer (P = 0.022) than untreated fruit upon arrival in Taiwan. After ambient storage (23°C) of fruit from container 1 for 45 h, fruit firmness declined (P<0.001) from an average of 65.7 to 43.2 N and there was no difference (P = 0.826) between treated or untreated fruit. It is concluded that ReTain application to 'Arctic Snow' nectarines can increase financial returns to growers through increased fruit size and quality benefits as well as maintain a higher flesh firmness following export.


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