Producción CyT
Congreso
Autoría
Gomez Ivan
;
Hajirezaei MR
;
GUIAMET, JUAN JOSE
;
Martínez DE
Fecha
2023
Editorial y Lugar de Edición
Asociación Sociedad Argentina de Fisiología Vegetal
Resumen
Información suministrada por el agente en
SIGEVA
Autophagy modulates sugar cell efflux from leaves in Arabidopsis Gómez Iván, Hajirezaei Mohammad-Reza, Guiamet Juan José, Martinez Dana Instituto de Fisiología Vegetal (INFIVE)- UNLP CONICET, La Plata, ArgentinaLeibniz Institute of Plant Genetics and Crop Plant Research (IPK), AlemaniaSugars serve as energy and as signaling molecules, affecting plant developmental processes such as source-sink relationships, growth and senescence. Plants with impaired autophagy are h...
Autophagy modulates sugar cell efflux from leaves in Arabidopsis Gómez Iván, Hajirezaei Mohammad-Reza, Guiamet Juan José, Martinez Dana Instituto de Fisiología Vegetal (INFIVE)- UNLP CONICET, La Plata, ArgentinaLeibniz Institute of Plant Genetics and Crop Plant Research (IPK), AlemaniaSugars serve as energy and as signaling molecules, affecting plant developmental processes such as source-sink relationships, growth and senescence. Plants with impaired autophagy are hypersensitive to carbon starvation, displaying early senescence and growth arrest. Autophagic mechanisms might be involved in cellular partitioning of sugars. We performed a GC-MS/MS based comparative analysis of intra- and extracellular pools of sucrose, glucose, and fructose in leaves of Arabidopsis, wild-type (WT) and autophagy knockout (atg5.ko) backgrounds, grown in soil under 12h light-12h dark photoperiod. We quantified pools of sugars in mature leaves attached to or detached from the plant at the end of the light period and kept in the dark overnight or for 72 hs. Also, phloem exudates (PE) were obtained from attached leaves. All the samples were collected after the end of the night period. Leaf apoplastic fluid (AF) was obtained by infiltration-centrifugation, then the leaves were ground in liquid N and used as the intracellular fraction. At least 40 leaves were used per treatment. WT leaves had lower ratio of Suc/Glc and of extra/intracellular sugar pools and higher sugar content than atg5.ko in all the conditions, indicating that autophagy contributes to intracellular sugar accumulation and down-regulates the outflow of sugars to the apoplast. This was even more noticeable when sugar export was impaired, in overnight detached leaves. After 72hs in darkness, leaves showed signs of senescence (chlorophyll and protein loss), more advanced in atg5.ko. Leaf sugar content and extra/intracellular ratio decreased in both genotypes, but this cellular partition declined less in atg5.ko. PE from atg5.ko had markedly higher concentration of sugars (per leaf fresh weight) than that of WT. Together, these results suggest that autophagy modulates sugar efflux from mature and senescing leaves, and that sugar export rate from source leaves is partially independent of carbon allocation and sink strength.
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Palabras Clave
autophagyleavesArabidopsissugar efflux