Source-sink imbalance increases with growth temperature in the spring geophyte Erythronium americanum

Gandin Anthony, Gutjahr Sylvain, Dizengremel Pierre, Lapointe Line. 2011. Source-sink imbalance increases with growth temperature in the spring geophyte Erythronium americanum. Journal of Experimental Botany, 62 (10) : 3467-3479.

Quartile : Q1, Sujet : PLANT SCIENCES

Résumé : Spring geophytes produce larger storage organs and present delayed leaf senescence under lower growth temperature. Bulb and leaf carbon metabolism were investigated in Erythronium americanum to identify some of the mechanisms that permit this improved growth at low temperature. Plants were grown under three day/night temperature regimes: 18/14 _C, 12/8 _C, and 8/6 _C. Starch accumulated more slowly in the bulb at lower temperatures probably due to the combination of lower net photosynthetic rate and activation of a 'futile cycle' of sucrose synthesis and degradation. Furthermore, bulb cell maturation was delayed at lower temperatures, potentially due to the delayed activation of sucrose synthase leading to a greater sink capacity. Faster starch accumulation and the smaller sink capacity that developed at higher temperatures led to early starch saturation of the bulb. Thereafter, soluble sugars started to accumulate in both leaf and bulb, most probably inducing decreases in fructose-1,6-bisphosphatase activity, triose-phosphate utilization in the leaf, and the induction of leaf senescence. Longer leaf life span and larger bulbs at lower temperature appear to be due to an improved equilibrium between carbon fixation capacity and sink strength, thereby allowing the plant to sustain growth for a longer period of time before feedback inhibition induces leaf senescence.

Mots-clés Agrovoc : Liliaceae

Mots-clés géographiques Agrovoc : Québec

Mots-clés complémentaires : Erythronium americanum

Classification Agris : F62 - Physiologie végétale - Croissance et développement

Champ stratégique Cirad : Hors axes (2005-2013)

Auteurs et affiliations

• Gandin Anthony, Université Laval (CAN)
• Gutjahr Sylvain, CIRAD-BIOS-UMR AGAP (FRA)
• Dizengremel Pierre, INRA (FRA)
• Lapointe Line, Université Laval (CAN)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/560398/)

Métriques

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