We investigated the role of ethylene diamine tetra-acetic acid (EDTA) and somaclonal manipulation on improving lead (Pb) phytostabilization in mat rush (Juncus effusus L.). Seedlings were raised from seeds and callus to study variations in Pb uptake and tolerance. The seedlings were treated with 0.5 and 1.0mM Pb as alone, and each with 2.5 and 5.0mM of EDTA. Plants grown from both sources accumulated relatively larger Pb contents in their root tissues that were further enhanced by EDTA supplementation in the hydroponics medium. The tendency of storing higher Pb contents in roots compared to shoots in J. effusus was also evident from lower translocation factor (TF) value that facilitated the plants to avoid from Pb-induced shoot injury. Callus grown plants were more responsive to EDTA amendment showing improved growth, Pb uptake and chlorophyll contents under Pb stress. Both kinds of J. effusus plants tolerated Pb toxicity by modifying antioxidative enzyme activities. Enrichment of Pb-treated media with EDTA further elevated enzymic activities of plant roots contributing to defy Pb-induced oxidative burst. Thus, plant improvement through somaclonal manipulation in J. effusus along with EDTA enrichment could be an appropriate technique for phytostabilization of Pb-contaminated environments

The aim of the present study was to investigate the effect of withering timings (i.e. 0, 21, 22, 23 and 24h) on the moisture, total free amino acids, ash, essential and toxic mineral element contents of tea (Camellia sinensis L.) leaves during black tea manufacturing. Moisture, ash, Na, P, Mg, Cu, Zn, Mn, Al, Ni and Pb contents were significantly (P0.05) results were noted for total free amino acids, K, Fe and Cd contents. The highest moisture content (76.4%) was examined in fresh leaves that progressively decreased to 63.8% in 24h withering. Total free amino acid contents gradually increased up to 23h and then decreased. Ash, P, Cu, Zn and Mn contents showed an increasing trend with withering time. Conversely, significantly lowered amounts of Na (162.5mg/kg) and Mg (803mg/kg) were recorded in tea leaves after 24h withering. Among the toxic elements, Al, Ni and Pb contents were progressively increased over withering time. It was concluded that tea is a potential source of essential chemical constituents and during processing proper care should be taken to produce high quality black tea

Background and aims Use of zinc (Zn) fertilisers may be cost-effective in increasing crop yields and in alleviating dietary Zn deficiency. However, Zn fertilisers are underutilised in many countries despite the widespread occurrence of Zn-deficient soils. Here, increased Zn fertiliser-use scenarios were simulated for wheat production in Punjab and Sindh Provinces, Pakistan. Inputs and outputs were valued in terms of both potential yield gains as well as health gains in the population. Methods The current dietary Zn deficiency risk of 23.9 % in Pakistan was based on food supply and wheat grain surveys. “Disability-adjusted life years (DALYs) lost” are a common metric of disease burden; an estimated 245,000 DALYs y⁻¹ are lost in Punjab and Sindh due to Zn deficiency. Baseline Zn fertiliser-use of 7.3 kt y⁻¹ ZnSO₄.H2O was obtained from published and industry sources. The wheat area currently receiving Zn fertilisers, and grain yield responses of 8 and 14 % in Punjab and Sindh, respectively, were based on a recent survey of >2500 farmers. Increased grain Zn concentrations under Zn fertilisation were estimated from literature data and converted to improved Zn intake in humans and ultimately a reduction in DALYs lost. Results Application of Zn fertilisers to the area currently under wheat production in Punjab and Sindh, at current soil: foliar usage ratios, could increase dietary Zn supply from ~12.6 to 14.6 mg capita ⁻¹ d⁻¹, and almost halve the prevalence of Zn deficiency, assuming no other changes to food consumption. Gross wheat yield could increase by 2.0 and 0.6 Mt. grain y⁻¹ in Punjab and Sindh, respectively, representing an additional return of US$ >800 M and an annual increased grain supply of 19 kg capita ⁻¹. Conclusions There are potential market- and subsidy-based incentives to increase Zn fertiliser-use in Pakistan. Benefit-Cost Ratios (BCRs) for yield alone are 13.3 and 17.5 for Punjab and Sindh, respectively. If each DALY is monetised at one to three fold Gross National Income per capita on purchasing power parity (GNI_PPP), full adoption of Zn fertiliser for wheat provides an additional annual return of 405–1216 M International Dollars (I$) in Punjab alone, at a cost per DALY saved of I$ 461–619.