时间: 2018年11月7日，上午9:00-11:00
地点：博学报告厅
主办单位：海峡联合研究院园艺中心
报告人一：TetsuyaHigashiyama
Instituteof Transformative Bio-Molecules (WPI-ITbM), NagoyaUniversity,
报告题目一：Dynamicsand key signalling molecules of pollen tube guidance
Academiccareer:
2013-(present)Vice Director, Institute of Transformative Bio-Molecules (WPI-ITbM), NagoyaUniversity
2007-presentProfessor, Nagoya University;
1999-2006ResearchAssociate, University of Tokyo;
1999Ph.D. University of Tokyo;
Summary:
Successfulsexual reproduction of flowering plants involves complex cell-to-cellcommunication. We have been working on pollen tube guidance, doublefertilization, and early embryogenesis by live-cell analysis. In pollen tubeguidance, defensin-like peptide LUREs are pollen tube attractants ofTorenia andArabidopsis secretedby two egg-accompanying “synergid cells” (Science2001; Nature 2009;PLoSBiol. 2012).To understand the molecular mechanism of pollen tube guidance, we have beentaking two approaches of live-cell study. The first approach is to use preciselydefined semi-in vitro system (semi-in vivo system), including development ofvarious microfluidics devices (e.g., RSCAdv. 2013;Biomicrofluidics 2018). Semi-in vitro studies combined with synthetic chemistrylead to discovery of novel intercellular signaling molecules involved in pollentube guidance. Arabinogalactan sugar chain AMOR derived from Torenia ovularsporophytic tissues is critical to make pollen tubes competent before attractionby TfLUREs (Curr. Biol. 2016; Plant Physiol. 2017). PRK6 is a receptor kinase ofArabidopsis,which is critical in sensing of AtLURE1 peptides (Nature 2016). Cocrystalstructure analysis of AtLURE1 and PRK6 suggested unique action mechanism ofAtLURE1 (Nat. Commun. 2017). The second approach is based on in vivo imaging. Wehave shown that pollen tube guidance is intimately related with doublefertilization (e.g., Dev. Cell 2013; Cell2015).By using two-photon microscopy, we have succeeded in visualizing pollen tubeguidance in the pistil tissue (e.g., Development 2015, Protoplasma 2015). Inthis talk, I will talk about recent progresses of our pollen tube guidance studyto discuss how pollen tubes are navigated to ovules, focusing on precisedirectional control, competency control, species-specific attraction, andone-to-one relationship between multiple ovules and pollen tubes.
Publications:
HigashiyamaT. et al. (2001) Science 293,1480-1483; Okuda S. et al. (2009) Nature458,357-361; Hamamura Y. et al. (2011) Curr.Biol. 21,497-502; Takeuchi H. and Higashiyama T. (2012) PLoSBiol.,e1001449; Maruyama D. (2015) Cell61,907-918; Gooh K. (2015) Dev.Cell34,242-251; Mizukami A.G. et al. (2016) Curr.Biol. 26,1091-1097; Takeuchi H. and Higashiyama T. (2016) Nature 531,245-248; Zhang X. et al. (2017) Nat.Commun. 8,1331.
报告人二：ToshinoriKinoshita
Instituteof Transformative Bio-Molecules (ITbM), Nagoya University
报告题目二：Regulationof light-induced stomatal opening and the plasma membrane H+-ATPase
Academiccareer:
2013-presentProfessor,Institute of Transformative Bio-Molecules (ITbM),
Director, Center for Gene Research, Nagoya University
2010-presentProfessor,Graduate School of Science, Nagoya University
2007-2010AssociateProfessor, Graduate School of Science, Nagoya University
2005-2009PRESTOResearcher, Japan Science and Technology Agency
2003-2004VisitingScientist, Salk Institute (Prof. Joanne Chory)
1994-2007ResearchAssociate, Assistant Professor, Kyushu University
Summary:
Stomatain the plant epidermis control gas exchange between plants and atmosphere.Stomatal aperture is regulated by many environmental signals, such as light,water status, temperature, and CO2.Under blue light, plasma membrane (PM) H+-ATPasein stomatal guard cells is activated via blue light-receptor phototropins andsignaling mediators, such as BLUS1, BHP, and PP1. Blue light-activated PMH+-ATPaseprovides driving force for stomatal opening. However, details of the signalingbetween phototropins and PM H+-ATPasestill remain unclear. Therefore, we are trying to clarify this signaling pathwayby several methods. In addition, based on the results from these basicresearches, we are trying to control stomatal aperture by genetic and chemicalapproaches, and found that enhancement of light-induced stomatal opening byoverexpressing PM H+-ATPasein guard cells increases photosynthesis and plant growth, and that suppressionof stomatal opening by chemicals confers drought tolerance on plants. Theseresults clearly indicate that manipulation of stomatal aperture is very usefultechnique for controlling plant growth and survive.
PMH+-ATPasehas critical roles not only in stomatal opening, but also in cell expansion,nutrient uptake, maintenance of membrane potential, and so on. Recently, wefound that PM H+-ATPaseactivity is regulated by plant hormones, auxin and brassinosteroid, in theetiolated seedlings and photosynthesis in mesophyll cells. I also will talkabout the regulation of PM H+-ATPaseby these signals.
Publications:
Tohet al. (2018) PlantCell Physiol,59, 1568-1580., Uchidaet al. (2018)NatChem Biol,14,299-305., Hayashiet al. (2017)SciRep,7, 45586., Inoue and Kinoshita (2017) PlantPhysiol,174,531-538., Okumuraet al. (2016) PlantPhysiol,171,580-589., Wanget al. (2014) PNAS,111,533-538., Takahashiet al. (2012) PlantPhysiol,Okumura et al. (2012) PlantPhysiol,159, 826-834., Kinoshita et al. (2011)CurrBiol,21, 1232-1238., Kinoshita et al. (2001) Nature,414, 656-660.