Growth alteration and leaf biochemical responses in Phaseolus vulgaris exposed to different doses of ionising radiation

Abstract

Ionising radiation may have different effects on plant metabolism, growth and reproduction, depending on radiation dose, plant species, developmental stage and physiological traits. In this study, exposure of dwarf bean plants to different doses of X-rays (0.3, 10, 50, 100 Gy) was investigated with a multidisciplinary approach consisting of morphological, ecophysiological and biochemical analysis. Both mature and young leaves still growing during the X-rays exposure were compared with non-irradiated control leaves. In particular, leaf expansion, leaf anatomy and functional traits, as well as photosynthetic pigment content and Rubisco expression were analysed. Moreover, the activity of poly(ADP-ribose) polymerase (PARP) was also measured as an indicator of radiation-induced DNA damage. Our data showed that leaf growth is affected by high levels of radiation and demonstrate that mature leaves are more radio-resistant than young leaves, which experience severe dose-dependent changes in leaf functional traits. In particular, young leaves exhibited a reduction of area and an increase in specific mass and dry matter content, as well as a decline in Rubisco activity. Moreover, they showed elevated PARP activity and an increase in phenolic compounds in wall cells if compared with mature leaves. Both of these strategies have been interpreted as a way to help developing leaves withstand irradiation.

Growth Retardation at Different Stages of Bean Seedlings Developed from Seeds Exposed to Synchrotron X-Ray Beam

“…The effect of x-ray irradiation on NRA has not been reported yet. Though the increased expression of Ribulose bis phosphate carboxylase and decreased expression of poly (ADP-ribose) polymerase in response to irradiation of dwarf bean plants by x-radiations has been reported [6]. In the present investigation, the nitrate reductase activity of the developing leaves was reduced significantly with perfect correlation in response to irradiation (Table 3).…”

“…Although reduced leaf growth parameters, such as leaf area, dry mass, pigment content etc. upon irradiation of dwarf bean plants to x-radiations, have been reported [6], the synchroton x-ray irradiation affecting growth has not been reported yet. In this study, the effect of x-ray exposure of Phaseolus vulgaris seeds on phosphate mobilization in soaked seeds, overall growth and nitrate assimilation in seedlings has been studied.…”

The effect of anthocyanin-rich bilberry extract on the antioxidant system in roots of barley (Hordeum vulgare L.) cultivars under ionizing radiation

“…anthocyanin rich extract) enzymes such as POD, SOD, GR, and APX. The increase or decrease in the activity of the enzymes cited above depends on the sensitivity of the plant species and the level of IR involved (Wada et al 1998;Zaka et al 2002;Gill and Tuteja 2010;Arena et al 2014). The results of the present study show that POD activity was inhibited while SOD, APX, and GR activities were enhanced by treatment with IR in both barley cvs (Fig.…”

“…While low-level radiation of 2 Gy can stimulate plant growth, high-level radiation, such as 50 Gy, inhibits it (Kim et al 2005;Arena et al 2014;De Micco et al 2014).…”

Leaf Anatomy and Photochemical Behaviour ofSolanum lycopersicumL. Plants from Seeds Irradiated with Low-LET Ionising Radiation

“…In Space, a large fraction of the dose is delivered by protons (approximately 87%), which are low-LET particles with similar effectiveness compared to X-rays. Therefore, initial studies can exploit conventional X-rays as the reference radiation to obtain data which are the necessary basis for future comparison using accelerated ion beams [13, 14]. The severity of the effects of low- and high-LET ionising radiation depends on several factors related to the radiation itself (e.g., type, total dose, and dose rate) and to plant features (e.g., species, cultivar, plant age, complexity of the target organ or tissue, and level of ploidy) [2, 15].…”