Crop productivity and yield are adversely affected by the deficiency of P in agricultural soil. Phosphate fertilizers are used at a large scale to improve crop yields globally. With the rapid increase in human population, food demands are also increasing. To see that crop yields meet demands, farmers have continuously added phosphate fertilizers to their arable fields. As the primary source of inorganic phosphorous, rock phosphate is finite and the risk of its being jeopardized in the foreseeable future is high. Therefore, there is a dire need to improve plant-available P in soil, using feasible, environmentally friendly technologies developed on the basis of further understanding of P dynamics between soil and plants. This study systemically reviews the mechanism of P uptake and P-use efficiency by plants under starvation conditions. The recent advances in various strategies, especially imaging techniques, over the period 2012–2021 for the measurement of plant-available P are identified. The study then examines how plants fulfill P requirements from tissue-stored P during P starvation. Following this understanding, various strategies for increasing plant-available P in agricultural soil are evaluated. Finally, an update on novel carriers used to improve the P content of agricultural soil is provided.

Background: Nickel (Ni) is a toxic heavy metal and causes human health risks as well as plant abnormalities. The present study aimed to determine morpho-anatomical features of Cucurbita pepo L. var. fastigata under combined drought and Ni stress in greenhouse experiment.Methods: Seedlings were treated with four irrigation levels to induce drought stress 14 ml, 11.2 ml, 8.4 ml and 5.6 ml (abbreviated as S0, S1, S2 and S3) along with 25 ppm of Nickel.Results: The results were analyzed after 5th and 10th days and data revealed that seed germination rate and stem diameter was significantly (P≤ 0.05) increased while stem length, root length, root diameter, the number of secondary roots, leaf area, fresh weight, and dry weight were decreased. Among anatomical characteristics epidermis, xylem, phloem tissues, cortex, trichomes, medullary rays, endodermis, pericycle, palisade, mesophyll cells, and stem mid rib were adversely affected under water stress (S1 and S2) while plants under combined Ni stress showed significant (P≤ 0.05) reduction in cortex diameter, and increase in epidermis thickness, vascular bundles size except for S3 treatment level.Conclusion: It was concluded that combined drought and Ni stress positively affected the morphological features (roots, stem length, and leaf area) of the Cucurbita pepo plant as compared to separate water and Ni stress, preventing plant wilting.Keywords: Nickel, drought stress, anatomy, morphology, Cucurbita pepo L.

Water pollution is a major environmental issue and human health risk worldwide. With rapid industrialization and economic growth, water bodies are contaminated at large scale. In the current study the concentration of four heavy metals (HMs) cadmium (Cd), copper (Cu), nickel (Ni), and manganese (Mn) was measured in water, sediment, and hydrophytes (Eichhornia Crassipes, Pistia stratiotes and Lemna minor) samples collected from wastewater stream in Sheikhupura, Punjab, Pakistan. The results revealed that the concentrations of Cd (0.23 mg L-1), Cu (5.00 mg L-1), Mn (6.00 mg L-1), and Ni (3.00 mg L-1) in water samples were above the permissible limits (APL) set by the World Health Organization (WHO). However, the concentration of Cd, Cu, Mn, and Ni in sediment samples was found to be below the maximum permissible limits (BMPL) set by WHO. The WHO permissible limits for Cd, Cu, Mn, and Ni in water is 0.01, 0.02, 0.20, and 1.40 mg L-1 respectively while in sediments is 3.00, 100, 2000, and 50 mg kg-1 respectively. In addition, Mn concentration was highest among all the tested hydrophytes, water, and sediment samples. HMs contents were higher in hydrophytes as compared to water and sediment samples. In addition, all three hydrophytes were found to absorb HMs from wastewater with bioaccumulation factor ranging from 2.52 to 216. Current data revealed that Pistia stratiotes have greater potential to absorb HMs from water as compared to Eichhornia Crassipes, and Lemna minor