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Abstract Detail

Recent Topics Posters

Lapointe, Line [1], Dong, Yanwen [2], Munne-Bosch, Sergi [3], Gérant, Dominique [4].

The effect of growth temperature on the metabolite and phytohormone profile as leaf ages and enters senescence.

Leaf senescence can be induced either by an abiotic stress, by environmental cues such as a photoperiod or in response to a change in plant carbon and/or nutrient needs. For example, leaf senescence can be induced by a reduction in sink demand once sink growth is completed. The signalling pathway that induces leaf senescence has only been partially uncovered, and it appears to vary depending on the driving cause of senescence (stress, phenology or sink limitation). Until recently, metabolites and phytohormones involved in the induction of senescence were investigated mostly on a one to one basis. New technologies such as metabolomic allow us to investigate the potential role of a much larger pool of metabolites in the induction of leaf senescence. We characterized leaf metabolite and phytohormone profiles in Erythronium americanum, a spring ephemeral, in which leaf senescence has been shown to be induced by a reduction in sink demand. Different growth temperatures were used to modulate sink demand and the timing of senescence. The leaf metabolite profile, which included over 80 different metabolites and 7 phytohormone classes, presents clear changes with leaf phenology, according to PCA analyses. A first group of metabolites is associated with leaf unrolling, a second group with fully developed leaves and a third group with leaf senescence. This last group includes plants that were harvested a few days before the first visual sign of leaf senescence, strongly suggesting that some of these metabolites are involved in the induction of leaf senescence. Amino acids are more abundant in developing leaves whereas many sugar components increased as leaf age. To our knowledge, some of these sugars have not been reported to be associated with leaf senescence in other species. Senescence is associated with large changes in phytohormone profile along with the synthesis of tocopherol. Growth temperature influence both the phytohormone and the metabolite profile associated with the induction of leaf senescence. Further investigation is needed to determine which metabolites are modulated in response to a sink limitation and those that might be specific to this group of plants. These studies will most likely unravel new signalling pathways that can induce leaf senescence.

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1 - Université Laval, Biologie, Pavillon Vachon, Quebec City, QC, G1V 0A6, Canada
2 - Université Laval, Département de biologie / Centre d'étude de la forêt, 1045, avenue de la Médecine, Pavillon Vachon, Bureau 3047-E, Québec, QC, G1V 0A6, Canada
3 - Universitat de Barcelona, Departament de Biologia Vegetal, Barcelona, Spain
4 - Université de Lorraine - INRA, Écologie et Écophysiologie Forestières, Nancy, France

source–sink relationship
low temperature
spring ephemerals.

Presentation Type: Recent Topics Poster
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PRT060
Abstract ID:1872
Candidate for Awards:None

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