Gas exchange and chlorophyll a fluorescence measurements as proxies of X-ray resistance in Phaseolus vulgaris L.

Gas exchange and chlorophyll a fluorescence measurements as proxies of X-ray resistance in Phaseolus vulgaris L. Radiat Environ Biophys. 2019 Aug 28;: Authors: Guadagno CR, Pugliese M, Bonanno S, Manco AM, Sodano N, D'Ambrosio N Abstract Phaseolus vulgaris L. plants were irradiated with different doses (0.3, 10, 50 and 100 Gy) of X-rays in order to obtain a reference curve of response to ionizing radiations for this species. Growth analysis, gas exchange and chlorophyll a fluorescence measurements were performed to estimate the radio-resistance of bean plants. Specifically, there was a negative influence of X-rays on the net photosynthesis rate at 50 and 100 Gy, already on the day of irradiation. Experimental data showed a recovery over time in the gas exchange while the theoretical maximum photochemical efficiency of the photosystem II (Fv/Fm) was fairly constant throughout the period of measurements (20 days) and for all the experimental conditions. On the other hand, the quantum yield of PSII linear electron transport (ΦPSII) and non-photochemical quenching (NPQ) were deeply influenced over time by X-ray dose, suggesting a decrease in the functionality of the photosynthetic apparatus at the highest radiation doses. The growth was affected only at the highest doses of radiation with a significant and severe reduction of leaf expansion and number of leaves per plant. Despite the arrest in growth, X-ray exposure seems to trigger an...
Source: Radiation and Environmental Biophysics - Category: Physics Authors: Tags: Radiat Environ Biophys Source Type: research