A morphological and cytological study of Petunia hybrida exposed to UV-B radiation

Staxén, Irina; Bornman, Janet F.

doi:10.1034/j.1399-3054.1994.910427.x

Cited by 21 publications

(20 citation statements)

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“…An increase in leaf thickness as a response to u.v. radiation has been documented previously (Murali & Teramura, 1986;Murali, Teramura & Randall, 1988;Cen & Bornman, 1990Bornman & Vogelmann, 1991), as well as a decrease (Staxen & Bornman, 1994).…”

Section: Resultsmentioning

confidence: 99%

A three‐dimensional representation of the relationship between penetration of u.v.‐B radiation and u.v.‐screening pigments in leaves of Brassica napus

1995

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SUMMARYA three-dimensional (3-D) representation of the penetration of u.v.-B (280-320 nm) radiation using fibre-optic microprobes, and of the spectrophotometric analysis of u.v.-screening pigments in leaves of Bras.ii.ca napus L. cv. Ceres is presented. In this way the results from radiation measurements were directly related to the distribution of u.v.-screening pigments. Brassica napus was grown in a greenhouse chamber with a photon flux density of 740 /imo\ m"^ s"^ photosynthetically active radiation (400-700 nm) with or without the addition of u.v.-B radiation. The amount of u.v-B added was equi\-alent to 9 kj m"' d"' biologically effective u.v.-B. Growth parameters measured included leaf thickness and dry weight. Ultraviolet-B radiation stimulated the accumulation of increased amounts of screening pigments, located mostly beneath the adaxial surface of tbe leaf, l^eaf dry weight decreased by 15 "o in u.v.-treated plants and, on a dry weight basis, chlorophyll content increased by 19 "o in treated leaves. The chlorophyll profiles within leaves from both control and u.v.-treated plants showed an increase from the adaxial surface to a plateau in the middle of the leaf, at a leaf depth of c. 150-320/im. Relatively large amounts of 285 nm radiation penetrated into leaves of u.v.-B treated plants to sites located within the initial 40 //m of the leaf. Thus, despite the presence of additional screening pigments, u.v.-B radiation was capable of reaching potential targets within the epidermis and mesophyll.

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Section: Resultsmentioning

confidence: 99%

A three‐dimensional representation of the relationship between penetration of u.v.‐B radiation and u.v.‐screening pigments in leaves of Brassica napus

1995

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“…UV-B radiation may also affect the key stages of cell division through transcriptional repression of the genes encoding for a mitotic cyclin. 130 The reduction in leaf size of UV-B exposed Arabidopsis plants has been associated to decrease in the cell expansion of the adaxial epidermal cells. 131 Jansen 105 found that the UV-B-induced reduction in plant growth, and more specifically in leaf area, has been attributed either to cell division or cell expansion or a combination of both.…”

Section: Staxen and Bornmanmentioning

confidence: 99%

“…Previous studies suggested that UV-B-reduced leaf expansion is completely due to UV-B-mediated inhibition of cell division in Lactuca sativa and Avena sp, 124 A. Thaliana, 125 cucumber cotyledons, 126 parsley, 127 wheat leaves, 128 barley leaves, 129 tomato hypocotyls 58 and petunia leaf protoplasts. 130 Repair of UV-B damage to DNA before replication and direct UV-B-induced oxidation of tubulin are mechanisms responsible for reduced cell division include oxidation of tubulin, which could delay microtubule formation. …”

Section: Interaction Of Cytokinins With Uv-b Stressmentioning

confidence: 99%

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

Kataria¹,

Kn²

2018

HIJ

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The negative effect on plant responses are expected due to increased amounts of ultraviolet-B (UV-B) radiation reaching on the Earth's surface by stratospheric ozone depletion. Cytokinins (CKs) are essential phytohormones in plant growth and development. Perusal of relevant literature reveals that CKs mitigate the oxidative damage caused by abiotic stresses like salt, drought, high temperature and heavy metal due to their antioxidant effects. However, very few reports are available on the interaction of CKs with UV-B stress on the expansion growth of the cucumber cotyledons. CKs induced the expansion growth of the excised cucumber cotyledons in the darkness. CKs induced expansion growth of cucumber cotyledons in darkness was inhibited by supplemental UV-B. UV-B radiation enhanced the level of oxyradicals like superoxide and hydroxide radicals in the excised cucumber cotyledons, which was evident by EPR spectroscopy. CKs like Zeatin, TDZ, BAP and FAP reduced the level of oxyradicals produced in the dark grown cucumber cotyledons, while promoting the expansion growth of the cotyledons. Production of oxyradical in UV-B exposed cotyledons showed that these oxyradicals might partially account for inhibition of expansion growth. Since considerable amount of oxyradicals were quenched by CKs at higher concentrations (10 and 20 µg/ml) it partially restores the inhibition of expansion growth caused by UV-B stress. It indicates that overproduction of oxyradicals by UV-B could not be entirely responsible for the inhibition of CKs induced expansion growth of cotyledons; which might be caused by some other physiological changes caused by UV-B irradiation in addition to the production of oxyradicals. UV-B is also known to inactivate protein inhibitor of peroxidase in cucumber cotyledons. This may reduce the antioxidants defence and enhance the damaging effects of oxyradicals for the growth of cotyledons.

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“…Existing data on the effects of UV-B on cell proliferation and cell expansion are contradictory, probably reflecting differences in experimental conditions. Acute, stress-inducing UV-B conditions usually inhibit cell proliferation, while both cell proliferation and expansion are affected by lower doses and/or chronic UV-B treatments (Staxen and Bornman, 1994;Nogués et al, 1998;Laakso et al, 2000;Hopkins et al, 2002;Hofmann et al, 2003;Kakani et al, 2003;Hectors et al, 2007Hectors et al, , 2010Wargent et al, 2009;Robson and Aphalo, 2012). For example, the number of epidermal cells at maturity decreased after UV-B exposure in some species (Gonzalez et al, 1998;Hopkins et al, 2002); on the contrary, in lettuce (Lactuca sativa) leaves, UV-B reduced cell expansion rate and final leaf size (Wargent et al, 2009).…”

mentioning

confidence: 99%

UV-B Inhibits Leaf Growth through Changes in Growth Regulating Factors and Gibberellin Levels

et al. 2017

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Ultraviolet-B (UV-B) radiation affects leaf growth in a wide range of species. In this work, we demonstrate that UV-B levels present in solar radiation inhibit maize (Zea mays) leaf growth without causing any other visible stress symptoms, including the accumulation of DNA damage. We conducted kinematic analyses of cell division and expansion to understand the impact of UV-B radiation on these cellular processes. Our results demonstrate that the decrease in leaf growth in UV-B-irradiated leaves is a consequence of a reduction in cell production and a shortened growth zone (GZ). To determine the molecular pathways involved in UV-B inhibition of leaf growth, we performed RNA sequencing on isolated GZ tissues of control and UV-B-exposed plants. Our results show a link between the observed leaf growth inhibition and the expression of specific cell cycle and developmental genes, including growth-regulating factors (GRFs) and transcripts for proteins participating in different hormone pathways. Interestingly, the decrease in the GZ size correlates with a decrease in the concentration of GA19, the immediate precursor of the active gibberellin, GA1, by UV-B in this zone, which is regulated, at least in part, by the expression of GRF1 and possibly other transcription factors of the GRF family.

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A morphological and cytological study of Petunia hybrida exposed to UV-B radiation

Cited by 21 publications

References 0 publications

A three‐dimensional representation of the relationship between penetration of u.v.‐B radiation and u.v.‐screening pigments in leaves of Brassica napus

A three‐dimensional representation of the relationship between penetration of u.v.‐B radiation and u.v.‐screening pigments in leaves of Brassica napus

Interaction of cytokinins with UV-B (280 -315nm) on the expansion growth of cucumber cotyledons

UV-B Inhibits Leaf Growth through Changes in Growth Regulating Factors and Gibberellin Levels

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