light photoreceptors to some extent, even the phytochromes, making study of the exclusive role of a single blue-light recep- tor extremely difficult. Although ...
Molecular Plant
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Volume 1
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Number 1
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Pages 2–3
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January 2008
Editorial In the Light of Day: Plant Photomorphogenesis It takes only the most cursory glance over the tables of contents of the top journals in plant biology to recognize that plant biology research in China is not only of the highest caliber, but is growing rapidly. Support for plant science in China is generous and is increasing, and Chinese plant biologists have joined those from other countries in producing some of the most exciting and innovative research. When I was given an opportunity to participate in the launching of a new English-language journal, the decision to take this assignment was an easy one. The time was clearly right to initiate an English-language journal with its home in China, with an international editorial board, and with the highest standards. The journal was launched with the enthusiastic support of Oxford University Press and eventually named Molecular Plant. The editors then gave me the opportunity to invite colleagues in the area of plant photoreceptors and morphogenesis to contribute to the first issue. To my great delight, the response was overwhelmingly positive. Remarkably, a large number of these colleagues not only had materials ready for our publication schedule, but also shared our excitement with this new undertaking and contributed manuscripts. You can see the results in this first issue. Some colleagues had stories that were not sufficiently developed to include but will nevertheless have articles in the second issue. I am thrilled with the outcome and offer these initial contributors my heartfelt thanks. The contributions to this inaugural issue represent a remarkable range of approaches to understanding role of light in regulating plant form, function, and development at the molecular level. Let me use blue-light reception to elucidate this statement: the article by Inoue et al., demonstrating that the phototropins regulate leaf position with respect to the direction of incident light relies heavily on physiology. Stone et al. use a combination of genetics and physiology to establish a role for AUX1-dependent auxin influx in phototropism. The article by Wan et al, describing in detail the relocalization of phototropin 1-GFP on irradiation of etiolated seedlings with blue light, is almost entirely based on cell biology. Using bioluminescence resonance energy transfer and transient expression in onion epidermal cells and Arabidopsis protoplasts, Rosenfeldt et al. developed an ingenious system for chemically activating cryptochrome in darkness, obviating the ever present problem that blue light activates all of the plant visiblelight photoreceptors to some extent, even the phytochromes, making study of the exclusive role of a single blue-light receptor extremely difficult. Although indirect evidence from ex-
pression of cryptochromes in a heterologous system suggested that the principle antenna pigment is likely a pterin, Hoang et al., using spectroscopy, show for the first time that a pterin indeed serves this function in planta. Sullivan et al. use mass spectrometry to identify sites on Arabidopsis phototropin 1 that are phosphorylated as a consequence of blue-light activation in vivo—an important goal that had remained elusive. Finally, Yang et al., using proteomics, demonstrate a function for the cryptochromes independent of photoexcitation. Other studies represent an equally wide range of different approaches: in a unique proteomic study, Gong et al. constructed protein microarrays containing many hundreds of transcription factors and then used them for analysis both of transcription-factor/DNA interactions and transcriptionfactor/protein interactions. Meng et al. made effective use of genetic variation in Arabidopsis to identify six quantitative trait loci responsible for cold-tolerant dark germination in a study that is completely genetics-based. Cloix and Jenkins used chromatin immunoprecipitation (ChIP) to elucidate the binding of the UVB-signaling component UVR8 to a localized region of chromatin, preferentially with histone H2B. Andronis et al. utilized a variety of binding assays to demonstrate that the clock protein CCA1 and the transcription factor HY5 associate physically and that CCA1 modifies the binding of HY5 to the G-box element in the promoter of the circadian-regulated gene encoding a chlorophyll a/b-binding protein. The work describes another important piece of the central circadian oscillator in plants. Staneloni et al. identify a promoter region in a phytochrome-regulated gene that is required for down-regulation in response to oxidative stress or high light—a region that, when mutated, does not affect phytochrome regulation of the gene itself, thus distinguishing for the first time regions of a single promoter involved in stress signaling from those involved in phytochrome signaling. By mutating the 10 serines in the extreme N-terminal region of phytochrome A, Kneibl et al. showed that whereas wild-type phyA could complement very low fluence, and low-fluence responses, the serines to alanines mutant was most effective in complementing highirradiance responses, suggesting a differential role for phosphorylation at the N-terminus for the different types of phytochrome-A responses. Kilian et al. demonstrated that
ª The Author 2007. Published by Oxford University Press on behalf of CSPP and IPPE, SIBS, CAS. doi: 10.1093/mp/ssm023
Editorial
the single-transmembrane helix, high-light-inducible genes in a hot spring cyanobacterium are differentially induced under a range of different stress conditions, suggesting that they may play subtly different roles, both in light harvesting and in photoprotection. Finally, Lin et al. provide evidence from transcriptional-activation and overexpression studies that the transcription factor RAP2.4 acts somewhere downstream from both light and ethylene signaling, adding one more link in the complex regulatory network controlled by light and hormones. This truly international group of authors has provided a magnificent example of the rigorous science that the editors
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of Molecular Plant expect and has allowed us to produce an exceptional inaugural issue. It is our hope and expectation that the world-wide community of plant biologists will find Molecular Plant an appropriate journal to which to submit some of their most exciting findings. I am extremely grateful to the editors of Molecular Plant and Oxford University Press for providing me with the opportunity to organize this inaugural issue. Seldom have I had such a gratifying experience.
Winslow R. Briggs
