S23 - Session P10 - Transcriptomic response of lettuce (Lactuca Sativa L.) leaves to a postharvest intermittent-light treatment during storage

Authors: Florence Charles, Cedric Dresch, Thomas Baron *, Julie Ripoll, Veronique Vidal, Sandrine Laurent, Claire Bourlieu, Nathalie Barouh, Pierre Villeneuve, Christian Chervin, Huguette Sallanon

The quality of ready-to-eat lettuce strongly depends on storage conditions, diverse light cycle treatments have been suggested to maintain quality. We have recently shown that low-level intermittent light could help to preserve the quality of packaged lettuce leaves. This work studied the effect of a two-day intermittent-light treatment (2 h on, 2 h off; 50 µmol m-2 s-1) followed by 5 days of dark storage, on packaged lettuce leaves at the transcriptome level. It evaluated impact of light on photosynthesis, carbon storage, membrane maintenance and lipids degradation related genes. The transcriptomic data highlighted the induction of carbon metabolism in chloroplast-related genes only during the two days of intermittent light, but this was not the case at day 7. Concerning membrane maintenance and lipids degradation, at day 2, some genes were differentially expressed, but unclear results avoid interpretation. At day 7 (after intermittent light treatment), most genes related to membrane maintenance were downregulated suggesting a negative remaining effect of light. The number of lipid degradation genes upregulated were equal at those downregulated at day 7. Some starch metabolism (anabolism and catabolism) related genes were upregulated at day 2, but not at day 7. This set of data is a resource for teams studying the postharvest behavior of plant leaves.