Effects of Lead Salts on Growth, Chlorophyll Contents and Tissue Concentration of Rice Genotypes

Abstract

Lead (Pb) is one of the most abundant heavy metal pollutants and readily absorbed by plants that exerts toxic effects and also gets entered into human food chain. There are very few examples of genetic differences being exploited to produce low Pb rice food through decreased metal uptake from Pb-polluted environment. In this regard, solution culture screening has been proposed as a rapid technique for the identification of prospective rice genotypes. In a hydroponics study, fourteen rice genotypes were tested against varying rates of applied Pb, to investigate the effects of chloride, sulfate and nitrate salts of Pb on growth, chlorophyll contents and tissue concentration of rice genotypes. The plants were exposed to 0, 100 and 200 µM Pb as PbCl 2 , PbSO 4 and Pb(NO 3 ) 2, separately for 42 days. Thus, there were seven treatments arranged in completely randomized design each with four replications. The results showed that at a certain defined Pb rate (100 or 200 µM), the toxic effects of Pb as Pb(NO 3 ) 2 to rice plants were found significantly (p ≤ 0.05) higher than PbCl 2 and PbSO 4 treatments. At all applied Pb treatments, the Shaheen Basmati and KS-282 were found tolerant to Pb because of higher growth, total chlorophyll contents, low root and shoot Pb concentration. Therefore, these both genotypes were found to be a good source for future rice breeding programs or grown by the farmers for Pb risk-free rice production in Pb polluted environment.

The Assessment of Metal Resistance through the Expression of Hsp-70 and HO-1 Proteins in Giant Reed

“…It is a known fact that metal exposure results in oxidative stress [27]. Stress responsive genes may be expressed upon the exposure of plants to some toxic metals and subsequent increased ROS levels, their binding proteins, DNA damage, and lipid peroxidation [28][29][30]. Variable miRNA levels have been noted upon exposure to abiotic stress in plants under the influence of specific genes, which seemed to be an adaptation to stress [31].…”

Differences in stress defence mechanisms in germinating seeds of Pinus sylvestris exposed to various lead chemical forms

“…The main objectives of our research were to examine the effect of Pb on germination and the emergence of pine seedlings and to determine the degree of phytotoxicity of various Pb compounds: Pb(NO 3 ) 2 and PbCl 2 . Different chemical forms of Pb affect plants, change their biological properties, and are taken from the ground, transposed and accumulated in plant organs, ultimately leading to death [ 34 , 35 ]. The authors [ 34 ] stated that Pb bioavailability/phytotoxicity also grew with increasing Pb forms and concentrations differently applied.…”

“…Different chemical forms of Pb affect plants, change their biological properties, and are taken from the ground, transposed and accumulated in plant organs, ultimately leading to death [ 34 , 35 ]. The authors [ 34 ] stated that Pb bioavailability/phytotoxicity also grew with increasing Pb forms and concentrations differently applied. The Pb toxicity due to various inorganic Pb salts was found in the decreasing order of Pb(NO 3 ) 2 > PbCl 2 > PbSO 4 .…”

“…their biological properties, and are taken from the ground, transposed and accumulated in plant organs, ultimately leading to death [34,35]. The authors [34] stated that Pb bioavailability/phytotoxicity also grew with increasing Pb forms and concentrations differently applied. ) and the pH of the solution, which ultimately govern the heavy metal sorption processes [36].…”

Toxicidad del plomo en la germinación y el crecimiento de plántulas de Parkinsonia aculeata L.

“…El Pb(NO2)3 inhibió significativamente (P ≤ 0.05) el crecimiento de la radícula, y el rendimiento de la materia seca disminuyó hasta 10 %. La inhibición del crecimiento y del rendimiento en materia seca es un efecto muy conocido del plomo en altas concentraciones (Iqbal et al, 2017); la raíz es más afectada que el vástago, debido a que está en contacto directo con el Pb (Lamhamdi et al, 2011). El efecto del Pb en la germinación y crecimiento temprano de las plántulas de P. aculeata L. difiere en cuanto a los compuestos de Pb utilizados, debido a que la solubilidad, disponibilidad y fitotoxicidad tienen un papel importante (Truta et al, 2011;Iqbal et al, 2017).…”