記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of the American Chemical Society  

γ-Lactam derivatives with multiple contiguous stereogenic carbon centers are ubiquitous in physiologically active compounds. The development of straightforward and reliable synthetic routes to such chiral structural motifs in a stereocontrolled manner should thus be of importance. Herein, we report a strategy to construct polycyclic γ-lactam derivatives that contain more than two contiguous stereogenic centers in an enantioselective as well as atom-economic manner. Moreover, we have achieved the first enantioselective synthesis of strigolactam derivative GR-24, a racemic variant of which is a potential seed germination stimulator and plant-growth regulator. A key of the procedure presented here is a nickel(0)/chiral phosphoramidite-catalyzed asymmetric [2+2+1] carbonylative cycloaddition between readily accessible ene-imines and carbon monoxide, which proceeded enantioselectively to furnish up to 90% ee (>99% ee after recrystallization). The results of mechanistic studies, including the isolation of a chiral heteronickelacycle, support that the enantioselectivity on the two contiguous carbon atoms of the γ-lactams is determined during the oxidative cyclization on nickel(0).

DOI： 10.1021/jacs.9b12493

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記述言語：英語   出版者・発行元：Science  

The parasitic plant Striga hermonthica has been causing devastating damage to the crop production in Africa. Because Striga requires host-generated strigolactones to germinate, the identification of selective and potent strigolactone agonists could help control these noxious weeds. We developed a selective agonist, sphynolactone-7, a hybrid molecule originated from chemical screening, that contains two functional modules derived from a synthetic scaffold and a core component of strigolactones. Cooperative action of these modules in the activation of a high-affinity strigolactone receptor ShHTL7 allows sphynolactone-7 to provoke Striga germination with potency in the femtomolar range. We demonstrate that sphynolactone-7 is effective for reducing Striga parasitism without impinging on host strigolactone-related processes.

DOI： 10.1126/science.aau5445

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記述言語：英語   出版者・発行元：Plant and Cell Physiology  

Strigolactones (SLs) are plant hormones associated with diverse developmental processes including plant architecture and stress responses. SLs are exuded to the soil as an ecological signal to attract symbiotic arbuscular-mycorrhizal fungi. This ecological mechanism is also used by parasitic plants to detect the presence of host plants and initiate germination. The functional diversity of SLs makes SL biology so extensive that a single methodology is not sufficient to comprehend it. This review describes the theoretical and practical aspects of the design of small molecule probes that have been used to elucidate the functions of SLs. The lessons from the development of small molecules to tackle the unique questions in SL biology might be instructive in the extending field of chemical biology in plants.

DOI： 10.1093/pcp/pcy119

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Experimental Botany  

Plant-derived strigolactones have diverse functions at ecological scale, including effects upon the growth of plants themselves. The parasitic plants from the family Orobanchaceae interfere with the ecological and hormonal functions of strigolactones to generate unique germination abilities based on the sensing of host-derived strigolactones. Although the recent discovery of strigolactone receptors has enabled us to begin elucidating the mechanism of strigolactone perception, how perception relates to plant parasitism is still a mystery. In this review, we explore emerging questions by introducing recent advances in strigolactone research in parasitic plants. We also attempt to construct a conceptual framework for the unique in planta dynamics of strigolactone perception uncovered through the use of fluorescent probes for strigolactone receptors. Understanding the mechanisms of strigolactone-related processes is essential for controlling the parasitic plant Striga hermonthica, which has caused devastating damage to crop production in Africa.

DOI： 10.1093/jxb/ery061

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACS Central Science  

DWARF14 (D14) is a strigolactone receptor that plays a central role in suppression of shoot branching, and hence is a potential target to increase crop productions and biomass. Recently, we reported a fluorescence turn-on probe, Yoshimulactone Green (YLG), which generates a strong fluorescence upon the hydrolysis by D14-type strigolactone receptors. Herein, we applied a YLG-based in vitro assay to a high-throughput chemical screening and identified a novel small molecule DL1 as a potent inhibitor of D14. DL1 competes with endogenous strigolactones, thereby increasing the number of shoot branching in a model plant Arabidopsis as well as in rice. Thus, DL1 is expected to be useful not only as a tool to understand the biological roles of D14 receptors in plant growth and development, but also as a potent agrochemical to improve the crop yield.

DOI： 10.1021/acscentsci.7b00554

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Nature Chemical Biology  

Striga spp. (witchweed) is an obligate parasitic plant that attaches to host roots to deplete them of nutrients. In Sub-Saharan Africa, the most destructive Striga species, Striga hermonthica, parasitizes major food crops affecting two-Thirds of the arable land and over 100 million people. One potential weakness in the Striga infection process is the way it senses the presence of a host crop. Striga only germinates in the presence of the plant hormone strigolactone, which exudes from a host root. Hence small molecules that perturb strigolactone signaling may be useful tools for disrupting the Striga lifecycle. Here we developed a chemical screen to suppress strigolactone signaling in the model plant Arabidopsis. One compound, soporidine, specifically inhibited a S. hermonthica strigolactone receptor and inhibited the parasite's germination. This indicates that strigolactone-based screens using Arabidopsis are useful in identifying lead compounds to combat Striga infestations.

DOI： 10.1038/nchembio.2129

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Science  

Strigolactones are naturally occurring signaling molecules that affect plant development, fungi-plant interactions, and parasitic plant infestations. We characterized the function of 11 strigolactone receptors from the parasitic plant Striga hermonthica using chemical and structural biology. We found a clade of polyspecific receptors, including one that is sensitive to picomolar concentrations of strigolactone. A crystal structure of a highly sensitive strigolactone receptor from Striga revealed a larger binding pocket than that of the Arabidopsis receptor, which could explain the increased range of strigolactone sensitivity. Thus, the sensitivity of Striga to strigolactones from host plants is driven by receptor sensitivity. By expressing strigolactone receptors in Arabidopsis, we developed a bioassay that can be used to identify chemicals and crops with altered strigolactone levels.

DOI： 10.1126/science.aac9476

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Science  

Elucidating the signaling mechanism of strigolactones has been the key to controlling the devastating problem caused by the parasitic plant Striga hermonthica. To overcome the genetic intractability that has previously interfered with identification of the strigolactone receptor, we developed a fluorescence turn-on probe, Yoshimulactone Green (YLG), which activates strigolactone signaling and illuminates signal perception by the strigolactone receptors. Here we describe how strigolactones bind to and act via ShHTLs, the diverged family of α/β hydrolase-fold proteins in Striga. Live imaging using YLGs revealed that a dynamic wavelike propagation of strigolactone perception wakes up Striga seeds. We conclude that ShHTLs function as the strigolactone receptors mediating seed germination in Striga. Our findings enable access to strigolactone receptors and observation of the regulatory dynamics for strigolactone signal transduction in Striga.

DOI： 10.1126/science.aab3831

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記述言語：英語  

DOI： 10.1016/j.chembiol.2014.09.003

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1186/1741-7007-10-8

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/pcp/pcr176

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DOI： 10.4161/psb.19839

記述言語：英語  

DOI： 10.1039/c1mb05195d

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/NCHEMBIO.435

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記述言語：日本語   出版者・発行元：一般社団法人植物化学調節学会  

The use of small molecule for perturbing protein function have potential advantages to classic genetics, while genetics is still valuable in complementing disadvantages of small molecule approach. Although the theoretical framework of small molecule-approach have been established, practical aspect of this strategy still needs more examples to be discussed. Here, I discuss some practices from our current work related to small molecules, as with an attempt to show what experiments should be prioritized for small molecule approach.

DOI： 10.18978/jscrp.45.2_132

CiNii Research

記述言語：英語  

DOI： 10.1016/j.pbi.2009.07.018

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記述言語：英語  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.devcel.2004.06.017

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1046/j.1365-313X.2003.01939.x

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1006/dbio.2000.9632

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