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Photoinduction of seed germination in Arabidopsis thaliana is modulated by phototropis

100%

Jedynak P., Mysliwa-Kurdziel B., Turek E., Malec P.

Acta Biologica Cracoviensia. Series Botanica

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2013

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tom 55

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nr 1

Light exposure is an important environmental factor which breaks seed dormancy in many plant species. Phytochromes have been identified as playing a crucial role in perception of the light signal that releases seed germination in Arabidopsis. Phototropins (Phot1, Phot2) are blue/UV-photoreceptors in plants which mediate phototropic responses, chloroplast relocation, hypocotyl growth inhibition and stomata opening. We studied germination under different light conditions in Arabidopsis Phot1-null and Phot2-null mutants and in a double phot1phot2 mutant. Germination of single phot1 and phot2 mutants in darkness was much lower than in wildtype (WT) seeds, whereas double phot1phot2 mutant lacking both functional phototropins germinated at frequency comparable to WT seeds, irrespective of light and temperature conditions. Light treatment of imbibed seeds was essential for effective germination of phot1, irrespective of low-temperature conditioning. In contrast, cold stratification promoted dark germination of phot2 seeds after imbibition in dim light. Low germination frequency of phot1 seeds under low light intensity suggests that the presence of functional Phot1 might be crucial for effective germination at these conditions. The lower germination frequency of phot2 seeds under continuous light suggests that Phot2 might be responsible for stimulating germination of seeds exposed to direct daylight. Thus, the phototropin system may cooperate with phytochromes regulating the germination competence of seeds under different environmental conditions.

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Altered accumulation of different forms of protochlorophyllide in etiolated seedlings of photoreceptor mutants of Arabidopsis thaliana

100%

Turek E., Mysliwa-Kurdziel B., Malec P.

Biological Letters

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2005

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tom 42

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nr 2 Spec.Vol.

3

Variations in xanthophyll composition in etiolated seedlings of Arabidopsis thaliana correlate with protochlorophyllide accumulation

88%

Mysliwa-Kurdziel B., Jemiola-Rzeminska M., Turek E., Strzalka K., Malec P.

Acta Biochimica Polonica

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2012

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tom 59

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nr 1

Protochlorophyllide (Pchlide) accumulation and xantophyll composition were studied in 5-day old etiolated seedlings of three ecotypes of Arabidopsis thaliana: Columbia (Col-0), Landsberg erecta (Ler) and Wassiliewska (Ws). The total Pchlide level as measured by fluorescence spectroscopy varied significantly between ecotypes. A rapid HPLC method revealed quantitative differences in carotenoid composition. It was found that in the Ler ecotype any enhanced accumulation of Pchlide correlates with an increased level of lutein, suggesting the role of enzymes involved in lutein synthesis in cross-regulation between chlorophyll and carotenoid biosynthetic pathways. The function of the dark-accumulated carotenoid pool in seedling de-etiolation is discussed.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Acta Biologica Cracoviensia. Series Botanica

1 Biological Letters

3 Malec P.

3 Mysliwa-Kurdziel B.

3 Turek E.

1 Jedynak P.

1 Jemiola-Rzeminska M.

1 Strzalka K.

1 2013

1 2012

1 2005

Photoinduction of seed germination in Arabidopsis thaliana is modulated by phototropis

Altered accumulation of different forms of protochlorophyllide in etiolated seedlings of photoreceptor mutants of Arabidopsis thaliana

Variations in xanthophyll composition in etiolated seedlings of Arabidopsis thaliana correlate with protochlorophyllide accumulation