The genetic control of rice yield through gleaning superior genes ppt.pdf

The genetic control of rice yield through gleaning superior genes. Naoki Hirotsu Toyo University, Japan Two ways we should take 1 Cereals production ＝ × Yield per area Y ie ld ( t/ h a ) Cultivated area C u lt iv a te d a re a ( h a ) P ro d u c ti o n ( × 1 0 6 t) Source and Sink determine rice yield 2 Source Photosynthetic rate Carbohydrate translocation Sink Tiller number Grain number Grain size ＝ × Yield Sink size Source ability Many genes have been cloned from QTLs. 3 Grain size GS3 (Fan et al 2006) GW2 (Song et al 2007) SW5 (Shomura et al 2008) GS5 (Li et al 2011) GL3 (Zhang et al 2012) etc… Source strength GIF1 (Wang et al 2008) NAL1 (Takai et al 2013) …limited reports. Grain number Gn1a (Ashikari et al 2005) DEP1 (Huan et al 2009) WFP (Miura et al 2010) qTGW6 increases grain weight without decreasing filled grain ratio 4 Ishimaru (2003) Plant Physiology 133, 1083-1090. Positional cloning of qTGW6 5 1-bp del gives functional loss of the TGW6 protein Ishimaru and Hirotsu et al (2013) Nature Genetics 45, 707-711. Loss of TGW6 increases grain length 6 We could confirm that the loss of TGW6 increases grain length. What is the function of TGW6? structural approach 7 STR1 DFPase modeled TGW6 structure Ca2+ Cavity (substrate binding site) Ca2+ binding site (E59, N167, N228, D271) Catalytic dyad (H192, Y224) TGW6 might have hydrolase activity. similar to Strictosidine synthase Ident :37%, E-value: 1e-48 Key enzymes in alkaloid biosynthesis What is the substrate for TGW6? 8 Strictosidine Tryptamine IAA-glucose TGW6 surface model and docking simulation with substrates Secologanin TGW6 have hydrolyzing activities 9 IAA-Glc → IAA + Glc endosperm at 3 d.a.f Kasalath type TGW6 could not produce free IAA When does TGW6 work? 10 anti-sense sense in situ hybridization at 5 d.a.f (longitudinal section of ovary) The effect of loss of TGW6 to sink development Nipponbare NIL(TGW6)