Rut Sánchez-Bragado1, José Luis Araus2, Ursula Scheerer3, Jill E Cairns4, Heinz Rennenberg5, Juan Pedro Ferrio6,7. 1. Unitat de Fisiología Vegetal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain. rutsanchez@ub.edu. 2. Unitat de Fisiología Vegetal, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain. jaraus@ub.edu. 3. Chair of Tree Physiology, Institute of Forest Sciences, University of Freiburg, Freiburg im Breisgau, Germany. ursula.scheerer@ctp.uni-freiburg.de. 4. International Maize and Wheat Improvement Center (CIMMYT), Harare, Zimbabwe. j.cairns@cgiar.org. 5. Chair of Tree Physiology, Institute of Forest Sciences, University of Freiburg, Freiburg im Breisgau, Germany. heinz.rennenberg@ctp.uni-freiburg.de. 6. Chair of Tree Physiology, Institute of Forest Sciences, University of Freiburg, Freiburg im Breisgau, Germany. pitter.ferrio@pvcf.udl.es. 7. Department of Crop and Forest Sciences-AGROTECNIO Center, Universitat de Lleida, Avda. Rovira Roure 191, 25198, Lleida, Spain. pitter.ferrio@pvcf.udl.es.
Abstract
MAIN CONCLUSION: This paper provides new insights into source-sink relationships and transpiration processes which will eventually help to interpret δ (18) O as a genotype selection and ecophysiological tool for maize adaptation to drought. Oxygen isotope composition (δ(18)O) has been proposed as a phenotyping tool to integrate leaf transpiration in C4 crops, such as maize. Within this context we hypothesize that δ(18)O in leaves may reflect primarily environmental and genetic variability in evaporative processes, but that this signal may become dampened in transit from source to sink tissues. The aim of this study was to assess the relative importance of transpirative or translocation-related factors affecting δ(18)O in plant tissues of maize. We performed two water regime experiments, one with two varieties under semi-controlled conditions, and another in the field with 100 genotypes during two consecutive years. The δ(18)O in organic matter at the leaf base was strongly correlated with the δ(18)O in stem water, indicating that it could be a good proxy for source water in extensive samplings. Compared to leaves, we observed an (18)O depletion in silks and grains, but not in stem-soluble organic matter. We interpret this as evidence of exchange with unenriched water from source to sink, but mainly occurring within sink tissues. Although grain yield (GY) and physiological variables did not show clear intra-trial patterns against δ(18)O, the only tissues that correlated with GY in the linear regression approach were that of silks, giving an insight of evapotranspirative demand during female flowering and thus of potential maize lines that are better adapted to drought. This finding will eventually help to interpret δ(18)O as a genotype selection and ecophysiological tool for the adaption of maize and other crops to drought, offering insight into source-sink relationships and transpiration processes.
MAIN CONCLUSION: This paper provides new insights into source-sink relationships and transpiration processes which will eventually help to interpret δ (18) O as a genotype selection and ecophysiological tool for maize adaptation to drought. Oxygen isotope composition (δ(18)O) has been proposed as a phenotyping tool to integrate leaf transpiration in C4 crops, such as maize. Within this context we hypothesize that δ(18)O in leaves may reflect primarily environmental and genetic variability in evaporative processes, but that this signal may become dampened in transit from source to sink tissues. The aim of this study was to assess the relative importance of transpirative or translocation-related factors affecting δ(18)O in plant tissues of maize. We performed two water regime experiments, one with two varieties under semi-controlled conditions, and another in the field with 100 genotypes during two consecutive years. The δ(18)O in organic matter at the leaf base was strongly correlated with the δ(18)O in stem water, indicating that it could be a good proxy for source water in extensive samplings. Compared to leaves, we observed an (18)O depletion in silks and grains, but not in stem-soluble organic matter. We interpret this as evidence of exchange with unenriched water from source to sink, but mainly occurring within sink tissues. Although grain yield (GY) and physiological variables did not show clear intra-trial patterns against δ(18)O, the only tissues that correlated with GY in the linear regression approach were that of silks, giving an insight of evapotranspirative demand during female flowering and thus of potential maize lines that are better adapted to drought. This finding will eventually help to interpret δ(18)O as a genotype selection and ecophysiological tool for the adaption of maize and other crops to drought, offering insight into source-sink relationships and transpiration processes.
Authors: Llorenç Cabrera-Bosquet; Rossella Albrizio; Salvador Nogués; José Luis Araus Journal: Plant Cell Environ Date: 2010-12-15 Impact factor: 7.228
Authors: Rut Sanchez-Bragado; Maria Dolors Serret; Rosa Maria Marimon; Jordi Bort; José Luis Araus Journal: Plant Physiol Date: 2019-04-05 Impact factor: 8.340
Authors: María D Serret; Salima Yousfi; Rubén Vicente; María C Piñero; Ginés Otálora-Alcón; Francisco M Del Amor; José L Araus Journal: Front Plant Sci Date: 2018-01-04 Impact factor: 5.753