نتایج جستجو برای: uv b

تعداد نتایج: 961435  

لطیفه پوراکبر, مهدی عابدزاده

آثار ناشی از نازک شدن لایه اوزون و افزایش تابش پرتو فرابنفش توسط بسیاری از پژوهشگران بررسی شده است. هدف از پژوهش حاضر بررسی تأثیر پرتوهای UV-B و UV-C روی گیاه بادرنجبویه (Melissa Officinalis L.) و تأثیر سالیسیلیک اسید در کاهش آثار زیانبار این پرتوها بر این گیاه است. گیاه بادرنجبویه در شرایط گلخانه‌ای در اتاقک کشت و دمای متوسط 2±28 درجه سانتیگراد و شدت نور 150 میکرو اینشتین بر متر مربع بر ثانیه ...

Journal: :Investigative ophthalmology & visual science 2010
Arnaud Sauer Valérie Letscher-Bru Claude Speeg-Schatz David Touboul Joseph Colin Ermanno Candolfi Tristan Bourcier

PURPOSE To demonstrate the antimicrobial properties of riboflavin/UV-A (365 nm) against fungal pathogens. METHODS The antimicrobial properties of riboflavin/UV-A (365 nm), with or without previous treatment with amphotericin B, were tested on three groups of fungi selected from severe cases of keratomycosis: Candida albicans, Fusarium sp, and Aspergillus fumigatus. They were tested by using K...

Journal: :The Plant cell 2008
Paula Casati Mabel Campi Feixia Chu Nagi Suzuki David Maltby Shenheng Guan Alma L Burlingame Virginia Walbot

The nuclear proteomes of maize (Zea mays) lines that differ in UV-B tolerance were compared by two-dimensional gel electrophoresis after UV light treatment. Differential accumulation of chromatin proteins, particularly histones, constituted the largest class identified by mass spectrometry. UV-B-tolerant landraces and the B73 inbred line show twice as many protein changes as the UV-B-sensitive ...

2017
Julieta P. Fina Fiorella Masotti Sebastián P. Rius Franco Crevacuore Paula Casati

Arabidopsis has 12 histone acetyltransferases grouped in four families: the GNAT/HAG, the MYST/HAM, the p300/CBP/HAC and the TAFII250/HAF families. We previously showed that ham1 and ham2 mutants accumulated higher damaged DNA after UV-B exposure than WT plants. In contrast, hag3 RNA interference transgenic plants showed less DNA damage and lower inhibition of plant growth by UV-B, and increase...

2016
Sebastián P. Rius Julia Emiliani Paula Casati

P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces...

Journal: :The Plant cell 2014
Jennifer Lockhart

Most of us do what we can to avoid the DNA-damaging effects of UV-B rays. While plants can’t slap on sunscreen, put on a nice hat, or move to a shady spot, they too have ways to protect themselves from (and acclimate to) damaging UV-B radiation. For example, plants undergo UV-B-dependent photomorphogenic changes (see figure), including reduced hypocotyl and leaf expansion, increased stomatal cl...

2014
Chan Zhang Yong-Ping Yang Yuan-Wen Duan

Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Flo...

Journal: :Environmental Health Perspectives 1994
W Goettsch J Garssen A Deijns F R de Gruijl H van Loveren

To assess the possibility that increases in UV-B exposure on the earth's surface could lead to impaired resistance to several infectious diseases, we studied the effect of UV-B exposure on resistance against Trichinella spiralis. Wistar rats, orally infected with T. spiralis larvae, were exposed to suberythemal doses of UV-B radiation daily for 5 days at different time periods before or after i...

Journal: :Journal of experimental botany 2007
Bo Zhou Yuhua Li Zhiru Xu Haifang Yan Shinichiro Homma Saneyuki Kawabata

Ultraviolet A (UV-A)-mediated regulation of anthocyanin biosynthesis was investigated in swollen hypocotyls of the red turnip 'Tsuda'. The shaded swollen hypocotyls which contained negligible anthocyanin were exposed to artificial light sources including low fluence UV-B, UV-A, blue, red, far-red, red plus UV-A, far-red plus UV-A, and blue plus red. Among these lights, only UV-A induced anthocy...

Journal: :Plant physiology 1995
L G Landry C C Chapple R L Last

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...

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