ABSTRACT
Abstract Plants adjust their shoot growth to acclimate to changing environmental factors, such as to enhanced Ultraviolet-B (UV-B) radiation. However, people have ignored that plant roots can also respond to UV-B light. Here, we find the morphology curled wheat roots under UV-B radiation, that we call, "bending roots." The curly region is the transition zone of the root after observed at the cellular level. After exposed to enhanced UV-B radiation for 2 d (10.08 KJ/m2/d), cell size decreased and actin filaments gathered in wheat roots. We also find that H2O2 production increased and that content of the indole-3-acetic acid (IAA) increased remarkably. The pharmacological experiment revealed that actin filaments gathered and polymerized into bundles in the wheat root cells after irrigated H2O2 and IAA. These results indicated that actin filaments changed their distribution and formed the "bending root," which was related to H2O2 production and increase in IAA. Overall, actin filaments in wheat root cells could be a subcellular target of UV-B radiation, and its disruption determines root morphology.
Resumo As plantas ajustam o crescimento da parte aérea para se adaptarem a fatores ambientais variáveis, como o aumento da radiação ultravioleta B (UVB). No entanto, as pessoas ignoram que as raízes das plantas também podem responder à luz UVB. Neste estudo, verificamos a morfologia das raízes enroladas de trigo sob radiação UVB, o que chamamos de "raízes dobradas". A região encaracolada é a zona de transição da raiz no nível celular. Depois de exposição à radiação UVB aprimorada por 2 dias (10,08 KJ/m2/d), o tamanho das células diminuiu, e os filamentos de actina se reuniram. Também constatamos que a produção de H2O2 aumentou e que o conteúdo do ácido indol-3-acético (IAA) aumentou notavelmente. O experimento farmacológico revelou que os filamentos de actina se reuniram e polimerizaram em feixes nas células da raiz de trigo após irrigação com H2O2 e IAA. Esses resultados indicam que os filamentos de actina alteraram sua distribuição e formaram a "raiz dobrada", relacionada à produção de H2O2 e ao aumento do IAA. No geral, os filamentos de actina nas células da raiz de trigo podem ser um alvo subcelular da radiação UVB, e sua interrupção determina a morfologia da raiz.
Subject(s)
Triticum , Hydrogen Peroxide , Ultraviolet Rays , Actin Cytoskeleton , Plant RootsABSTRACT
Aim: The current experimental work has been designed to study the effect of UV-B exposure on the seedling growth and meiotic consequences of Eclipta alba (L.) Hassk.Methodology: The seedlings were exposed to UV-B radiation for different time durations, i.e., 40, 80, 120 min along with control sets. UV-B irradiated seedlings along with respective controls were sown in the field and young floral buds were fixed in Carnoy’s fixative for 24 hrs and preserved in 90% ethanol for meiotic study. Results: Exposure of UV-B exposure resulted in various chromosomal aberrations like stickiness, laggards, bridges, unorientation, precocious, multivalents etc. Chromosomal stickiness was profound abnormality encountered at shorter duration (40 min) to UV-B exposure. The results revealed that UV-B exposure for shorter duration is quite beneficial to plant as it induces significant cytomorphological and biochemical variations. Interpretation: Shorter exposure to UV-B radiation induced certain beneficial traits in Eclipta alba. Since, Eclipta alba is a medicinally significant plant, hence, it is essential to improve their quantitative and qualitative traits through induced mutagenesis using UV-B radiation to impel the novel characteristics of plant
ABSTRACT
Aim: A study was designed to measure the solar UV- B in Uttarakhand, Garhwal region and to observe the effect of retene and psoralene photosensitizers on hill stream fishes, Tor tor and Garra gotyla in the presence of natural solar ultraviolet and equal intensity of artificial UV-B radiation.Methodology: Solar UV-B was measured with the help of Kipps and Zonen radiometer having UV-B sensors. Experimental sites selected were Dehradun and Tehri located in Garhwal region of Uttarakhand. The artificial radiation was provided with Philips UV-B Lamps. Mortality, biochemical and enzymological parameters, which included glutathione, glucose-6-phosphatase, catalase and lipid peroxidation were analyzed. Results: The data of monitoring of UV-B showed that the maximum UV-B intensity was observed during the month of May to August and the minimum was in the month of December to February. Mortality rate of fish exposed to solar radiation, artificial UV-B, psoralene and retene indicated highest with 26% in Tor tor, exposed with psoralene+ artificial UV-B. Reduced glutathione, glucose- 6- phosphatase and catalase level decreased in all the groups compared to control. The maximum reduction in GSH level was observed after treatment of artificial UV-B + psoralene in Tor tor, while maximum reduction in catalase and glucose-6- phosphatase was observed after retene and artificial UV-B. Interpretation: Tor tor and Garra gotyla are important hill stream fishes. Retene and psoralene are natural photosensitizers present in the aquatic ecosystem and become phototoxic by generating oxidative radicals. Artificial UV-B was more toxic than natural solar radiation and Tor tor was found more sensitive than Garra gotyla. Enhanced UV-B with retene and psoralene photosensitizers affect hill stream fishes and aquatic biodiversity.
ABSTRACT
A rice variety Jyothi (PTB 39) is a red kernelled with bold grain, popular in the region of Kerala, India used in the study. Plants were grown in pots under three different conditions, natural solar UV-B conditions, UV-B excluded condition using UV-B filters and supplemental UV-B using UV-B lamps along with ambient solar radiation. During the study period, UV-B radiation was in the range of 1.30 to 3.58 Wm2 which affected the productivity of the crop under open solar condition. A decrease in morphological traits like plant height, number of tillers, flag leaf angle and increase in leaf thickness were observed. Physiological parameters, leaf gas exchange parameters and biochemical constituents such as chlorophyll content also recorded less value under high UV-B condition along with the high content of protective compounds such as flavonoid content, catalase and PAL activity. The phenophases of the crop were also delayed by 4-5 days under UV-B radiation exposed conditions. All these negative impacts of UV-B radiation on crop leads to restricted filling of grain, lesser harvest index and grain development leading to a decrease in yield and yield attributing characters.
ABSTRACT
Abstract Plants adjust their shoot growth to acclimate to changing environmental factors, such as to enhanced Ultraviolet-B (UV-B) radiation. However, people have ignored that plant roots can also respond to UV-B light. Here, we find the morphology curled wheat roots under UV-B radiation, that we call, bending roots. The curly region is the transition zone of the root after observed at the cellular level. After exposed to enhanced UV-B radiation for 2 d (10.08 KJ/m2/d), cell size decreased and actin filaments gathered in wheat roots. We also find that H2O2 production increased and that content of the indole-3-acetic acid (IAA) increased remarkably. The pharmacological experiment revealed that actin filaments gathered and polymerized into bundles in the wheat root cells after irrigated H2O2 and IAA. These results indicated that actin filaments changed their distribution and formed the bending root, which was related to H2O2 production and increase in IAA. Overall, actin filaments in wheat root cells could be a subcellular target of UV-B radiation, and its disruption determines root morphology.
Resumo As plantas ajustam o crescimento da parte aérea para se adaptarem a fatores ambientais variáveis, como o aumento da radiação ultravioleta B (UVB). No entanto, as pessoas ignoram que as raízes das plantas também podem responder à luz UVB. Neste estudo, verificamos a morfologia das raízes enroladas de trigo sob radiação UVB, o que chamamos de raízes dobradas. A região encaracolada é a zona de transição da raiz no nível celular. Depois de exposição à radiação UVB aprimorada por 2 dias (10,08 KJ/m2/d), o tamanho das células diminuiu, e os filamentos de actina se reuniram. Também constatamos que a produção de H2O2 aumentou e que o conteúdo do ácido indol-3-acético (IAA) aumentou notavelmente. O experimento farmacológico revelou que os filamentos de actina se reuniram e polimerizaram em feixes nas células da raiz de trigo após irrigação com H2O2 e IAA. Esses resultados indicam que os filamentos de actina alteraram sua distribuição e formaram a raiz dobrada, relacionada à produção de H2O2 e ao aumento do IAA. No geral, os filamentos de actina nas células da raiz de trigo podem ser um alvo subcelular da radiação UVB, e sua interrupção determina a morfologia da raiz.
ABSTRACT
Ellagic acid (EA), an antioxidant polyphenolic constituent of plant origin, has been reported to possess diverse pharmacological properties, including anti-inflammatory, anti-tumor and immunomodulatory activities. This work aimed to clarify the skin anti-photoaging properties of EA in human dermal fibroblasts. The skin anti-photoaging activity was evaluated by analyzing the reactive oxygen species (ROS), matrix metalloproteinase-2 (MMP-2), total glutathione (GSH) and superoxide dismutase (SOD) activity levels as well as cell viability in dermal fibroblasts under UV-B irradiation. When fibroblasts were exposed to EA prior to UV-B irradiation, EA suppressed UV-B-induced ROS and proMMP-2 elevation. However, EA restored total GSH and SOD activity levels diminished in fibroblasts under UV-B irradiation. EA had an up-regulating activity on the UV-B-reduced Nrf2 levels in fibroblasts. EA, at the concentrations used, was unable to interfere with cell viabilities in both non-irradiated and irradiated fibroblasts. In human dermal fibroblasts, EA plays a defensive role against UV-B-induced oxidative stress possibly through an Nrf2-dependent pathway, indicating that this compound has potential skin antiphotoaging properties.
Subject(s)
Humans , Cell Survival , Ellagic Acid , Fibroblasts , Glutathione , Matrix Metalloproteinase 2 , Oxidative Stress , Plants , Reactive Oxygen Species , Skin , Superoxide DismutaseABSTRACT
The antioxidant and growth stimulating properties of seeds of Achyranthes aspera were evaluated on UV-B irradiated Catla catla (catla) larvae. Catla larvae (initial weight: 1.2 ± 0.01 mg) were fed with four different diets — D1, D2 and D3 containing 0.1, 0.25 and 0.5% seeds of A. aspera and D4, control diet for 35 days. The larvae were then exposed to UV-B radiation (80 µW/cm2) on every alternate day for 20 days. Survival, growth, tissue glutamic oxaloacetic transminase (GOT), tissue glutamate pyruvate transminase (GPT), thiobarbituric acid reactive substances (TBARS) and nitric oxide synthase (NOS) were studied in larvae on day-21 of irradiation. Significantly (P < 0.05) higher survival and average weight were found in D3 diet fed fish compared to the other groups. Survival rate was 8-16% higher in seed enriched diet fed groups, compared to the control one. Higher levels of GOT and GPT found in control diet fed larvae showed the degree of tissue damage due to UV-B exposure. Significantly (P < 0.05) lower level of GPT in D3 indicated the UV-B protective effect of the seed of A. Aspera (earlier, the presence of ecdysterone, essential fatty acids and amino acids, polyphenolic compounds, steroids, etc. has been reported from seed). TBARS which indicated the level of tissue lipid peroxidation were significantly (P < 0.05) higher in control group, compared to the other feeding schemes. NOS level was significantly (P < 0.05) higher in D2 and D3, compared to the D1 and control groups. In conclusion, supplementation of A. aspera seed (0.5%) improved the physiological condition (in terms of reduce lipid oxidation and better immune system) and gave bioprotection to catla larvae challenged with UV-B stress.
Subject(s)
Achyranthes , Animals , Carps/growth & development , Carps/physiology , Carps/radiation effects , Larva/growth & development , Larva/physiology , Larva/radiation effects , Survival , Ultraviolet RaysABSTRACT
Present study is conducted to evaluate the response of bean (Dolichos lablab cv . pusa early prolific) plants to supplemental UV-B (sUV-B: 280-315 nm: 7.2 kJ m-2 d-1) radiation. UV-B caused alteration in biomass translocation pattern with more retention of biomass in below ground parts leading to an increment in root shoot ratio. Specific leaf area (SLA) which is the measure of leaf thinness, increased in plants under sUV-B exposure by 95.7 and 82.3% after 15 and 30 days after germination. Photosynthetic machinery of bean plants was the potential target of UV-B as photosynthetic rate was decreased by 88.6 % at 30 days after germination. sUV-B lead to the formation of reactive oxygen species thus generating oxidative stress. Stimulation of antioxidant defense system (enzymatic and non-enzymatic) was observed due to sUV-B radiation. Phenolic content decreased (34.7 and 18.6%) but protein showed varied response, increased initially (34%) thereafter declined (10.2%) under sUV-B radiation.
ABSTRACT
Field studies were conducted for a season to determine potential for alterations in the rhizosphere fungi quantity dynamics and dominant populations of 4 wild sugarcane clones(S.spontaneum L.) with different UV-B sensitivity under an enhanced ultraviolet-B(UV-B,280 nm～310 nm) radiation.The quantity of rhizosphere fungi was most in tillering stage,second in seedling stage and lest in elongating stage and maturing stage,the sequence wasn’t alternated by UV-B radiation.The rhizosphere fungi quantity of tolerant clone was obviously increased and greater than the sensitive clone under the enhanced UV-B radiation,however,the number of dominant populations decreased and Penicillium was the dominant population during the periods of 4 wild sugarcane clones.