Macroalgal-derived alginate/wastepaper hydrogel to alleviate sunflower drought stress

Abstract

2-, > 1.6-, > 1.35-, and > 1.3-folds under both water regimes in relation to the no-hydrogel treatments at the same conditions. Furthermore, the sunflower shoots exhibited similar proline contents to the well-watered control (100% FC), with > 50% reduction in relation to the drought-stressed plants under the same conditions. Similarly, the malondialdehyde contents were lowered by > 15%. The analysis of the antioxidant enzymes also indicated a marked reduction in the specific activities of catalase and ascorbate peroxidase under both 75 and 50% FC compared to the respective controls. Additionally, the hydrogel promoted the uptake of phosphate by sunflower roots. These results implied that the developed biodegradable hydrogel could be effectively applied as a soil additive to alleviate drought stress on crops.