rootstock genetic background No Cochetel, Antoine Gautier, Elose - PowerPoint PPT Presentation

In grafted grapevines, physiological, transcriptional and hormonal responses to nutrient availability are strongly influenced by the rootstock genetic background Noé Cochetel, Antoine Gautier, Eloïse Météier, Isabelle Merlin, Cyril Hévin, Jean-Bernard Pouvreau, Pierre Coutos-Thévenot, Michel Hernould, Zhanwu Dai, Philippe Vivin, Pierre-François Bert, Frédéric Escudié, Mindy Stephania Muñoz, Christophe Klopp, Serge Delrot, Sarah Jane Cookson, Nathalie Ollat, and Virginie Lauvergeat

INT INTRODUCT CTION RESULTS CONCLUSION PERSPECTIVES C ULTIVATED GRAPEVINE , A GRAFTED PLANT • Conferred vigor • A rootstock adapted to the environment Phenology Yield Scion • A vegetative growth compatible with the production of Berry quality qualitative berries Rives, 1971 Champagnol, 1984 Ollat et al ., 2003 Jones et al ., 2009 Tolerance to disease Berry Rootstock and abiotic stress Quality Conferred vigour Smith, 2004 Pouget, 2015 Howell, 2001 Skinkis and Vance, 2013 Keller, 2015 How rootstocks control scion growth?

INT INTRODUCT CTION RESULTS CONCLUSION PERSPECTIVES H OW THE ROOTSTOCK CONTROLS THE SCION DEVELOPMENT ? • Nitrogen is an essential nutrient crucial for grapevine growth, berry yield and quality Scion • Nitrate is the main source of nitrogen Shoot and root growth regulation • Nitrate availability is heterogeneous in the soil Rootstock • Nitrate sensing and uptake are regulated by the rootstock to ensure an Hormones optimal absorption of this nutrient N N • Root and shoot growth are regulated in response to nitrate availability, Sensing of the availability especially through root to shoot long distance hormone signalling and nitrate uptake Are the rootstocks different in terms of nitrate sensing and uptake?

INT INTRODUCT CTION RESULTS CONCLUSION PERSPECTIVES H ORMONAL REGULATION OF SCION GROWTH • Strigolactones: - Mainly synthesized in the roots Scion - Regulated by nitrogen availability Shoot and root growth regulation - Inhibit axillary bud outgrowth Rootstock - Involved in arbuscular mycorrhizal fungi symbiosis in the rhizosphere Strigolactone Waldie et al ., 2014 N N Al-babili et al ., 2015 Lopez-Obando et al ., 2015 Pandey et al ., 2016 Sensing of the availability and nitrate uptake Do strigolactones contribute to the rootstock-dependent regulation of scion growth?

INTRODUCT INT CTION RESULTS CONCLUSION PERSPECTIVES P LANT MATERIAL • Choice of two rootstock genotypes known to differently control the growth of the same scion CS CS 1103P RGM

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES A RE THE ROOTSTOCKS DIFFERENT IN TERMS OF NITRATE SENSING AND UPTAKE ? • Profiling of the short term transcriptomic responses in the roots • Heterogeneous nitrate availability CS CS N N N N 1103P RGM Cochetel et al ., JXB, 2017

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES A RE THE ROOTSTOCKS DIFFERENT IN TERMS OF NITRATE SENSING AND UPTAKE ? • Split root system - ] [NO 3 HN LN 0.8 mM 5 mM CS CS LN HN LN LN HN LN 1103P RGM Root tips harvesting 3 & 24 hpt LN HN Cochetel et al ., JXB, 2017

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES A RE THE ROOTSTOCKS DIFFERENT IN TERMS OF NITRATE SENSING AND UPTAKE ? • De novo assembly of RNA sequencing results Combination Description Positive Negative Total HN3 vs LN3 132 73 205 CS/1103P HN24 vs LN24 5 3 8 HN3 vs LN3 449 103 552 CS/RGM HN24 vs LN24 221 710 931 • 172 common differentially expressed genes (DEGs) in both combinations related to nitrogen • A more pronounced response in CS/RGM: - More DEGs - Common DEGs with a higher LFC WGCNA revealed an interesting gene cluster related to strigolactone pathway. Cochetel et al ., JXB, 2017

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES S TRIGOLACTONE GENE CLUSTER Do strigolactones contribute to the rootstock- dependent regulation of scion growth? Cochetel et al ., JXB, 2017 Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES F UNCTIONAL CHARACTERIZATION OF GRAPEVINE STRIGOLACTONE GENES • Genes involved in SL biosynthesis mainly expressed in the roots • Over-expression of grape genes in Arabidopsis restored hyper-branched mutants to the WT branching phenotype • Overexpressing grapevine cells secreted SL-like compounds able to induce the germination of P. ramosa seeds Phelipanche ramosa seeds Pouvreau et al ., 2013 Grapevines produce SL-like compounds with similar roles as in other plant species. Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S SL PRODUCTION INDUCED BY N LIMITING CONDITIONS AND IMPACTED BY THE ROOTSTOCK IN MICROGRAFTS ? • Phenotypic and molecular responses to nitrate - Hydroponic experiments

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S SL PRODUCTION INDUCED BY N LIMITING CONDITIONS AND IMPACTED BY THE ROOTSTOCK IN MICROGRAFTS ? • Hydroponics – Experimental design Pre-cultured in Full nutrient 0N solution Treatment perlite solution H 2 O HN 0N HN H 2 O HN 0N 0N 0 7 9 14 16 21 23 28 35 Week 1 Week 2 (Days) Gene expression profiling Exudates collection Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES D O N LIMITING CONDITIONS INDUCE EXPRESSION OF SL BIOSYNTHESIS GENES ? • Hydroponics – Gene expression profiling Pre-cultured in Full nutrient 0N solution Treatment perlite solution H 2 O HN 0N HN H 2 O HN 0N 0N 0 7 9 14 16 21 23 28 35 Week 1 Week 2 (Days) Gene expression profiling Exudates collection Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES D O N LIMITING CONDITIONS INDUCE EXPRESSION OF SL BIOSYNTHESIS GENES ? • Hydroponics – Gene expression profiling 0N solution Treatment • Expression of genes involved in SL biosynthesis is regulated by N 0N HN availability in grafted grapevines. 0N 0N • This induction was higher in CS/RGM roots. Week 1 Week 2 MAX1 Combination Condition CS/1103P 0N CS/RGM HN Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S THE GENE EXPRESSION INDUCTION ASSOCIATED WITH SL PRODUCTION ? • Hydroponics – Bio-assays Pre-cultured in Full nutrient 0N solution Treatment perlite solution H 2 O HN 0N HN H 2 O HN 0N 0N 0 7 9 14 16 21 23 28 35 Week 1 Week 2 (Days) Transcript abundance quantification Exudates collection Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S THE GENE EXPRESSION INDUCTION ASSOCIATED WITH SL PRODUCTION ? • Hydroponics – Bio-assays CS/1103P – 0N CS/1103P – HN CS/RGM – 0N CS/RGM – HN Dilution 1/10 Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S THE GENE EXPRESSION INDUCTION ASSOCIATED WITH SL PRODUCTION ? Combination Condition • Hydroponics – Bio-assays CS/1103P 0N CS/RGM HN CS/1103P – 0N Week 2 Week 1 CS/1103P – HN CS/RGM – 0N CS/RGM – HN PDR1 • In N limiting conditions, grafted grapevines produced SL-like compounds. • SL production induction is earlier and stronger in CS/RGM plants. Cochetel et al ., JXB, 2018

INTRODUCTION RESULTS CONCLUSION PERSPECTIVES I S THE GENE EXPRESSION INDUCTION ASSOCIATED WITH SL PRODUCTION ? Combination Condition • Hydroponics – Bio-assays CS/1103P 0N CS/RGM HN CS/1103P – 0N Week 2 Week 1 CS/1103P – HN CS/RGM – 0N CS/RGM – HN PDR1 gene expression is induced in N limiting PDR1 conditions and more strongly in CS/RGM. • In N limiting conditions, grafted grapevines produced SL-like compounds. • SL production induction is earlier and stronger in CS/RGM plants. CS/1103P – 0N CS/1103P – HN CS/RGM – 0N CS/RGM – HN CS/1103P CS/RGM CS/1103P CS/RGM Cochetel et al ., JXB, 2018