Zinc Uptake by Young Wheat Plants under Two Transpiration Regimes

Abstract

AbstractTreated wastewater for crop irrigation is an alternative for countries with a shortage of fresh water. Such practice requires strict wastewater application criteria and a better understanding of the effects of transpiration rate on plant heavy metal uptake. The experiment measured Zn uptake by young wheat plants (Triticum aestivum L.) grown in triplicated experimental pots and held in two growth chambers with constant environmental conditions (relative humidity, light and temperature) but with a different air water vapor pressure deficit to produce two different transpiration rates. After 5 wk of growth in a greenhouse, the plants were transferred to the controlled chambers and irrigated using a fertilized solution with five different levels of Zn: 0, 2, 10, 25, and 50 mg/L. These Zn levels were low enough to have no significant effect on plant growth and transpiration rate. The wheat plants started to produce their grain at 6 wk. Plants were collected at 0, 3, and 10 d of incubation in the controlled chambers and analysed for dry matter and total Zn content. The pots were weighed daily to measure their transpiration rates. On Day 10, the remaining plants were collected and their roots, shoots, and grain were separated, weighed, dried, and analysed for total Zn. Time and plant transpiration rate were found to affect significantly plant Zn uptake. The higher transpiration rate enhanced plant Zn uptake. The roots had the highest Zn uptake followed by the shoots and then the grain.