(1) The effects of facilitation on the structure and dynamics of plant populations have not been studied so widely as competition. The UV-B radiation, as a typical environmental factor causing stress, may result in direct stress and facilitation. (2) The effects of UV-B radiation on intraspecific competition and facilitation were investigated based on the following three predictions on self-thi...

Changes in axial stress and refractive index have been measured as a function of the total UV-irradiation fluence during the formation of Bragg gratings in B/Geand Sn/Ge-codoped core fibers. For the B/Ge-codoped core fiber, a fast development of the type-I grating with a significant increase in refractive index and tensile stress in the fiber core is followed by a slow growth of the type-IIA gr...

Background & Aim: Thymus vulgaris L. and Thymus daenensis Celak (Thyme), members of the family Lamiaceae, are widely used in Iranian folk medicine. The aim of this research was to study how salicylic acid (SA), gibberellin (GA), and indole acetic acid (IAA)-seed priming affect UV-B radiation in seeds of Thyme (T. vulgaris, T. daenensis </...

Background & Aim: Thymus vulgaris L. and Thymus daenensis Celak (Thyme), members of the family Lamiaceae, are widely used in Iranian folk medicine. The aim of this research was to study how salicylic acid (SA), gibberellin (GA), and indole acetic acid (IAA)-seed priming affect UV-B radiation in seeds of Thyme (T. vulgaris, T. daenensis </...

The purpose of the present work was to evaluate both the antioxidant response system and oxidative stress in leaves from bitter gourd (Momordica charantia L) subjected to NaCl, UV-B and water stresses at three different stages of plant growth: pre-flowering, flowering and post-flowering. Except for peroxidase (POX), all enzyme activities including superoxide dismutase (SOD), catalase (CAT), pol...

High ultraviolet-B (UV-B; 290-320 nm wavelength) radiation may signifi cantly contribute to the quality decline and death of kentucky bluegrass (Poa pratensis L.) sod during summer transplanting. Antioxidants and protective pigments may be involved in plant defense against oxidative stress caused by UV-B. Selected exogenous hormones may alleviate UV-B damage by upregulating plant defense system...

For examining how UV-B radiation alters the proteome of the N2-fixing cyanobacterium, Anabaena L31, we extracted proteins from cultures irradiated with UV-B + white light and controls (white light irradiated) and analyzed the proteins using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). Twenty one proteins, in...

The effects of moderate salinity on the responses of woody plants to UV-B radiation were investigated using two Populus species (Populus alba and Populus russkii). Under UV-B radiation, moderate salinity reduced the oxidation pressure in both species, as indicated by lower levels of cellular H2O2 and membrane peroxidation, and weakened the inhibition of photochemical efficiency expressed by O-J...

We have assessed ultraviolet-B (UV-B)-induced injury in wild-type Arabidopsis thaliana and two mutants with altered aromatic secondary product biosynthesis. Arabidopsis mutants defective in the ability to synthesize UV-B-absorbing compounds (flavonoids in transparent testa 5 [tt5] and sinapate esters in ferulic acid hydroxylase 1 [fah1]) are more sensitive to UV-B than is the wild-type Landsber...

The study focuses on the effect of supplemental UV-B radiation on germination, seedling growth, chlorophyll a and b contents, soluble phenols, anthocyanins, flavones contents, phenylalanine ammonia lyase (PAL) activity and tyrosine ammonia lyase (TAL) activity of mash-bean (Vigna mungo (L.) Hepper.). Even though the germination velocity was substantially increased, the final germination percent...