THE ROOT ENDODERMIS ACTS AS A GATEWAY FOR VASCULAR TRANSPORT. David E Salt University of Aberdeen, UK SC UOLA SUPERIORE SANT ANNA, PISA

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1 THE ROOT ENDODERMIS ACTS AS A GATEWAY FOR VASCULAR TRANSPORT David E Salt University of Aberdeen, UK

2 Taiz& Zieger, 2010

3 SC UOLA SUPERIORE SANT ANNA, PISA

4 SC UOLA SUPERIORE SANT ANNA, PISA

5 SC UOLA SUPERIORE SANT ANNA, PISA

6 SC UOLA SUPERIORE SANT ANNA, PISA

7 Casparian strip contain lignin

8 Casparian strip contain lignin Casparian strip contain lignin and suberin is not a significant component of the Casparian strip

9 Casparian strip contain lignin Casparian strip contain lignin and suberin is not a significant component of the Casparian strip Casparian strip is made of lignin

10 The Casparian strip problem

11 Ionomics Linking genetics with high throughput elemental-profiling in A. thaliana ICP-MS Analysis Arabidopsis thaliana Sample preparation Bioinformatics Web Portal Plant Growth Salt et al Ann Rev Plant Biol (2008)

12 Plants grown in soil and leaves analyzed 2,000 FN 6,000 EMS Various fine mapping pop. ~1500 accessions 7 RIL populations 3,540 known genes 207,887 PLANTS ANALYZED SINCE DEC 2001 DATA AVAILABLE AT

13 Clustering ionomic mutants Z-score frd3 myb36 tsc10a sgn3 esb1 cpr5 npcc6 Uncharacterized mutants Mutant Soil batch Tray No. Se K Cr Na Li Mg P Fe Ca Cd Zn Mo Cu Ni As Pb Co Mn Huang & Salt Mol Plant (2016) based on data from Lahner et al., Nat Biotech (2003)

14 MYB36 localizes to the nucleus in the differentiation zone of the endodermis MYB36 genomic fragment fused with GFP transformed into myb36-1 Kamiya et al., PNAS (2015)

15 myb36 lacks a Casparian strip and has ectopic lignin Wild-type myb36-1 Wild-type myb36-1 End Cor Kamiya et al., PNAS (2015)

16 myb36 lacks a Casparian strip and has ectopic lignin Lignin - yellow Cell wall- blue Kamiya et al., PNAS (2015)

17 myb36 also has ectopic suberin Wild-type myb36-1 Stained with Fluorol Yellow 088 Kamiya et al., PNAS (2015)

18 MYB36 sufficient for Casparian strip formation Ecotopic expression of MYB36 transcription factor in the cortex sufficient for Casparian strip formation Lignin - yellow Cell wall- blue Kamiya et al., PNAS (2015)

19 MYB36 transcription factor regulates Casparian strip associated genes endodermis Yellow gene down regulated in myb36-1 Blue gene up regulated in myb36-1 PER64 CASP1 CASP3 CASP2 CASP4 CASP5 Kamiya et al., PNAS (2015)

20 SC UOLA SUPERIORE SANT ANNA, PISA

21 MYB36 also required for localisation of CASPs Localisation of CASP1 Kamiya et al., PNAS (2015)

22 ITQB-UNL FRO NTIER LEADER SEMINAR MYB36 transcription factor regulates Casparian strip associated genes endodermis Yellow gene down regulated in mutant Blue gene up regulated in mutant ESB1 Kamiya et al., PNAS (2015)

23 Clustering ionomic mutants esb1 Z-score frd3 tsc10a myb36 sgn3 cpr5 npcc6 Uncharacterized mutants Mutant Soil batch Tray No. Se K Cr Na Li Mg P Fe Ca Cd Zn Mo Cu Ni As Pb Co Mn Huang & Salt Mol Plant (2016) based on data from Lahner et al., Nat Biotech (2003)

24 ESB1 protein localizes to the Casparian strip Hosmani et al., PNAS (2013)

25 Casparian Strip in esb1 disorganized Wild-type esb1-1 Hosmani et al., PNAS (2013)

26 The esb1 mutant also has ectopic lignin and suberin general response to damaged Casparian strip? lignin suberin wild-type esb1-1 wild-type esb1-1 Stained with Fluorol Yellow 088 Hosmani et al., PNAS (2013)

27 CASP1 is mis-localized in esb1 mutant suggesting cross talk between ESB1 and CASPs Hosmani et al., PNAS (2013)

28 What is the function of ESB1? Some ideas 1. Limit lignin deposition. 2. Attach lignin to plasma membrane via CASPs. 3. Control polymerization of lignin.

29 Clustering ionomic mutants sgn3 Z-score frd3 tsc10a myb36 esb1 cpr5 npcc6 Uncharacterized mutants Mutant Soil batch Tray No. Se K Cr Na Li Mg P Fe Ca Cd Zn Mo Cu Ni As Pb Co Mn Huang & Salt Mol Plant (2016) based on data from Lahner et al., Nat Biotech (2003)

30 ..the function of SGN3 is unclear

31 Dr Ivan Baxter (Donald Danforth Plant Science Center) Dr Prashant Hosmani Dr Takehiro Kamiya (University of Tokyo) Dr Peng Wang Dr Guilhem Reyt Dr Xinyuan Huang Elena Yakubova BRETT LAHNER DR JOHN DANKU ANALYTICAL CHEMISTS Mary Lou Guerinot (Dartmouth College) Niko Geldner & Marie Barberon (University of Lausanne) Jan Schjørring, Søren Husted and Daniel Olof Persson (University of Copenhagen)