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1

Impact of pre-sowing magnetic field exposure of seeds to stationary magnetic field on growth, reactive oxygen species and photosynthesis of maize under field conditions

100%

Shine M. B. , Guruprasad K. N.

Acta Physiologiae Plantarum

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2012

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tom 34

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nr 1

EN

Impact of pre-sowing exposure of seeds to static magnetic field were studied on 1 month old maize [Zea mays. var: HQPM.1] plants under field conditions. Prestandardized magnetic field strength of 100 mT (2 h) and 200 mT (1 h), which were proven best for improving different seedling parameters under laboratory condition, were used for this study. Magnetic field treatment altered growth, superoxide radical level, antioxidant enzymes and photosynthesis. Among the different growth parameters, leaf area and root length were the most enhanced parameters (78–40%, respectively), over untreated plants. Electron paramagnetic resonance spectroscopy study showed that superoxide radical was reduced and hydroxyl radical was unaffected after magnetic field treatment. With decrease in free radical content, antioxidant enzymes like superoxide dismutase and peroxidase were also reduced by 43 and 23%, respectively, in plants that emerged from magnetically treated seeds. Measurement of Chlorophyll a fluorescence by plant efficiency analyzer showed that the potential of processing light energy through photosynthetic machinery was enhanced by magnetic field treatment. Performance index of the plant enhanced up to two-fold and phenomenological leaf model showed more active reaction centers after magnetic field treatment. Among the two field strengths used, 200 mT (1 h) was more effective in altering all these parameters. It is concluded that pre-sowing magnetic field treatment can be effectively used for improving plant growth and development under field conditions.

2

Regulation of growth and development in phytochrome mutants of Arabidopsis thaliana by solar UV

100%

Mani P. , Guruprasad K. N.

Acta Physiologiae Plantarum

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2015

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tom 37

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nr 06

EN

Phytochrome mutants (phyA, phyB and phyAB) of Arabidopsis thaliana were grown under ambient and UV-excluded sunlight to understand their influence on growth and development by mutual exclusion. Phytochrome A and B played a complementary role in the regulation of germination. Suppression of hypocotyl length was predominantly under the control of phytochrome B; UV photoreceptors were active in suppression of hypocotyl growth only in phyB and phyAB mutants. Exclusion of UV promoted the number and the area of rosette leaves only in presence of phytochrome A and B. Phytochrome mutation reduced petiole length, whereas UV exclusion led to an increase. Requirement of long-day period for flowering was removed in the mutants. Under short-day conditions, flowering was predominantly under the control of phytochrome B, since phyB mutants flowered earlier than phyA mutants. Solar UV regulates the number of boltings and number of siliques per plant. Overall biomass of the plants is enhanced by the exclusion of UV only in the wild type. The interaction of phytochromes with UV photoreceptors is discussed in the paper.

3

Photosynthesis and yield in cotton (Gossypium hirsutum L.) Var. Vikram after exclusion of ambient solar UV-B/A

80%

Dehariya P. , Kataria S. , Guruprasad K. N. , Pandey G. P.

Acta Physiologiae Plantarum

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2012

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tom 34

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nr 3

EN

The impact of ambient solar UV was studied on the photosynthesis and yield of cotton (Gossypium hirsutum) var. Vikram in a field experiment by excluding either UV-B (<315 nm) or UV-B/A (<400 nm) components of solar spectrum. Cotton plants were grown in cages covered with polyester filters that could specifically cut off UV-B or UVB/ A part of the solar spectrum. The control plants were grown under a filter transmissible to UV. Exclusion of UV enhanced plant height, leaf area, total biomass, and the yield parameters (number and weight of bolls, length of fiber and number of seeds) of cotton. Enhancement in the vegetative growth and yield of the plants could be related to enhanced rate of photosynthesis in the leaves. Polyphasic chlorophyll a fluorescence (OJIP) transients from UV excluded plants gave a higher fluorescence yield at I–P phase. Fluorescence measurements indicated enhanced Fv/Fm ratio and reduction capacity after exclusion of solar UV. Exclusion also enhanced stomatal conductance and intercellular CO₂ concentration and reduced the stomatal resistance. Total soluble proteins were higher after UV exclusion, and in SDS–PAGE analysis, bands corresponding to smaller subunits (14 kDa) of Rubisco were more intensely stained. Experiments indicated suppressive action of ambient UV on carbon fixation and yield of cotton plants. Exclusion of solarUVproved to be beneficial in enhancing the yield of cotton plants.

4

Effect of Exclusion of Ambient Solar Uv-A/B Components on Growth and Antioxidant Response of Cotton (Gossypium Hirsutum L.)

80%

Kataria S. , Dehariya P. , Guruprasad K. N. , Pandey G. P.

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nr 2

5

Intraspecific variations in antioxidant defense responses and sensitivity of soybean varieties to ambient UV radiation

80%

Baroniya S. S. , Kataria S. , Pandey G. P. , Guruprasad K. N.

Acta Physiologiae Plantarum

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2013

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tom 35

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nr 05

EN

Field experiments were conducted to determine the effects of exclusion ofUV-A/BandUV-Balone on growth parameters, activity of antioxidant enzymes, level of antioxidants and yield, to evaluate the intra-specific variations in sensitivity of these responses in eight soybean (Glycine max) varieties (PK-472, PK-1029, Pusa-24, JS-7105, JS-335, Hardee, NRC-7 and Kalitur). The plants were grown in specially designed UV-exclusion chambers which lined with selective UV filters to exclude either UV-B (\320 nm) or UV-A/B (\400 nm). Plants grown under UV-exclusion filters were compared with those grown under polythene filter which transmitted ambient UV-B and UV-A radiation. The results indicate that the exclusion of solar UV-B and UV-A/B enhanced the vegetative growth (plant height and leaf area), total biomass accumulation and yield (number of seeds and seedweight) of all the varieties as compared with those grown under ambientUV.The activities of SOD,GPX,APXandGR, and levels of ASA were significantly decreased, while atocopherol increased after the exclusion ofUV-BandUV-A/B in all varieties. These results suggest that the ambient level of UV-B and UV-A radiation evoked some active oxygen species to accumulate, which in turn retarded the growth, development and yield of soybean varieties. On the basis of biomass, UV-B (280–315 nm) sensitivity can be arranged in decreasing order as PK-472[Hardee[JS-335[Kalitur[ JS 71-05[Pusa-24[NRC-7[PK-1029 and UV-A/ B sensitivity can be arranged in decreasing order as PK- 472[Kalitur[JS-335[Hardee[Pusa-24[JS 71-05[ NRC-7[PK-1029. The results indicate var. PK-472 is more sensitive than other varieties and PK-1029 is least sensitive to ambient level of UV radiation. This study in the area of UV-B andUV-A/B stress provides an extensive data that can be used as a predictive basis in crop sciences to further investigate some of the tolerant varieties in field studies.

6

Foliar application of pyraclostrobin alleviates oxidative stress and improves carbon assimilation in soybean

80%

Joshi-Paneri J. , Sharma S. , Guruprasad K. N.

Acta Agrobotanica

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2023

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tom 76

7

Effect of exclusion of ambient solar UVA/B components on growth and antioxidant response of cotton ( Gossypium hirsutum L.)

80%

Kataria S. , Dehariya P. , Guruprasad K. N. , Pandey G. P.

Acta Biologica Cracoviensia. Series Botanica

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2012

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tom 54

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nr 2

EN

The influence of ambient solar UV-A or UV-B radiation on growth responses was investigated in three varieties of cotton (Gossypium hirsutum L.) after exclusion of solar UV-A/B radiation: JK-35, IH-63 and Khandwa-2. Cotton plants were grown from seeds in UV-exclusion chambers lined with selective UV filters to exclude either UV-B (280–315 nm) or UV-A/B (280–400 nm) from the solar spectrum under field conditions. Excluding UV-B and UV-A/B significantly increased plant height, leaf area and dry weight accumulation in all three varieties of cotton. The varieties differed considerably in their sensitivity to ambient UV-A/B. Khandwa-2 was most sensitive and JK-35 least sensitive to ambient solar UV. We monitored the activity of the antioxidant enzymes superoxide dismutase (SOD), ascorbic acid peroxidase (APX), glutathione reductase (GR) and guaiacol peroxidase (GPX), as well as the level of the antioxidant ascorbic acid (ASA), in primary leaves of the most UV-sensitive variety (Khandwa-2). The level of UV-B-absorbing substances was significantly decreased by exclusion of solar UV-B and UV-A/B. Exclusion of solar UV decreased the activity of all the antioxidant enzymes monitored and the level of ascorbic acid versus control plants (+UV-A/B) grown under filters transparent to solar UV. Reduction of the antioxidant defense after UV exclusion indicates that ambient solar UV exerts significant stress and induces some reactive oxygen species to accumulate, which in turn retards the growth and development of cotton plants. Ambient solar UV stresses cotton plants, shifting their metabolism towards defense against solar UV. Exclusion of solar UV eliminates the need for that defense and leads to enhancement of primary metabolism.