Urea is a crucial nutrient for plant growth, but because of its substantial losses due to nitrification, ammonification, and subsurface leaching, there is currently a push to reduce these losses. Urea is frequently uploaded and trapped in gelatin. In this research, the improvement of urea uploading and encapsulation efficiency is investigated using wood ash made from plant biomass (Pinus roxburghii). The 8 g w/v of gelatin was mixed with various concentrations of wood ash (from 4 to 16 g w/w), urea (from 4 to 24 g w/w), and glutaraldehyde (from 0.5 to 3 mL g⁻¹) to prepare various formulations of slow-release fertilizer (SRF). According to this study, adding wood ash to gelatin increases its ability to upload and encapsulate urea. The urea on its surface and the metal in wood ash both considerably contribute to the compositional alterations in gelatin in SRFs, which were demonstrated by IR spectroscopy. Visualization from photographs revealed that the homogenous dispersion of wood ash improved structural compatibility. The water content of the SRF formulation showed that wood ash can reduce water absorption by changing how hydrophobic gelatin is. Wood ash improves the gelatin’s ability to reduce the rapid release of urea over time, according to testing of cumulative urea release from SRF. The optimal combinations for achieving the maximum 53.43% of urea uploading were 2.44 g of urea, 2.47 mL of glutaraldehyde, and 1.50 g of wood ash, according to the Box–Behnken model. The gelatin-based SRF that had been amended with wood ash was applied to the Mentha spicata plant, and the plant’s healthy development and higher chlorophyll content revealed its agronomic potential. This study has a significant contribution to the development of an affordable and more effective wood ash-modified gelatin-based SRF.

None of our investigations have identified stress in response to the HSP70 and HO-1 proteins in metals under stress in our study, which aimed to understand the genetic basis of the metal tolerance of Arundo donax. Thus, the present work aimed to investigate the levels of expression of two important stress-related proteins, HO-1 and HSP70, in A. donax after exposure to various metals. The plants were collected from uncontaminated sites in Abbottabad, Pakistan. Their rhizomes were grown in Hoagland solution, and upon attaining suitable biomass, the plants were used to investigate the effects of metals on protein expression. The metal treatments were carried out with synthetic wastewater containing four Cr treatments (0, 34, 66, 134, and 267 mgL⁻¹), namely, Cd, As, Pb, Cu and Ni (0, 25, 50, 75, and 100 mgL⁻¹), and the plants were grown for three weeks. The treatments were applied according to a randomized block design (RBD) based on hydroponics. The selected protein expression was examined after 10 days of metal exposure. For the HSP70 and HO-1 protein studies, leaves were separated following a previously reported standard procedure. The maximum level of HO-1 and HSP70 expressions was noted at 66 mgL⁻¹ of Cr, and then it slightly declined. Significantly, high protein expression was observed at Cd exposure concentrations of 50 to 100 mgL⁻¹. For Cu, As and Ni, significantly high HO-1 and HSP70 expressions were noted at metal exposure concentrations of 75 to 100 mgL⁻¹. The expression levels of these two stress-related proteins showed a linear increase with increasing metal exposure in the giant reed. It is clear from the present research that HSP70 and HO-1 proteins may contribute significantly to plant tolerance to metal stress, in addition to other possible tolerance mechanisms.