1.
Meta-Analysis of the Transcriptome Reveals a Core Set of Shade-Avoidance Genes in Arabidopsis.
Sellaro, R, Pacín, M, Casal, JJ
Photochemistry and photobiology. 2017;(3):692-702
Abstract
The presence of neighboring vegetation modifies the light input perceived by photo-sensory receptors, initiating a signaling cascade that adjusts plant growth and physiology. Thousands of genes can change their expression during this process, but the structure of the transcriptional circuit is poorly understood. Here we present a meta-analysis of transcriptome data from Arabidopsis thaliana exposed to neighbor signals in different contexts, including organs where growth is promoted or inhibited by these signals. We identified a small set of genes that consistently and dynamically respond to neighbor light signals. This group is also affected by light during de-etiolation and day/night cycles. Among these genes, many of those with positive response to neighbor signals are binding targets of PHYTOCHROME-INTERACTING FACTORS (PIFs) and function as transcriptional regulators themselves, but none of these features is observed among those with negative response to neighbor signals. Changes. in neighbor signals can mimic the transcriptional signature of auxin, gibberellins, brassinosteroid, abscisic acid, ethylene, jasmonic acid and cytokinin but in a context-dependent manner. We propose the existence of a small core set of genes involved in downstream communication of PIF signaling status and in the control of light sensitivity and chloroplast metabolism.
2.
QTL meta-analysis in Arabidopsis reveals an interaction between leaf senescence and resource allocation to seeds.
Chardon, F, Jasinski, S, Durandet, M, Lécureuil, A, Soulay, F, Bedu, M, Guerche, P, Masclaux-Daubresse, C
Journal of experimental botany. 2014;(14):3949-62
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Abstract
Sequential and monocarpic senescence are observed at vegetative and reproductive stages, respectively. Both facilitate nitrogen (N) remobilization and control the duration of carbon (C) fixation. Genetic and environmental factors control N and C resource allocation to seeds. Studies of natural variation in Arabidopsis thaliana revealed differences between accessions for leaf senescence phenotypes, seed N and C contents, and N remobilization efficiency-related traits. Here, a quantitative genetics approach was used to gain a better understanding of seed filling regulation in relation to leaf senescence and resource allocation. For that purpose, three Arabidopsis recombinant inbred line populations (Ct-1×Col-0, Cvi-0×Col-0, Bur-0×Col-0) were used to map QTL (quantitative trait loci) for ten traits related to senescence, resource allocation, and seed filling. The use of common markers across the three different maps allowed direct comparisons of the positions of the detected QTL in a single consensus map. QTL meta-analysis was then used to identify interesting regions (metaQTL) where QTL for several traits co-localized. MetaQTL were compared with positions of candidate genes known to be involved in senescence processes and flowering time. Finally, investigation of the correlation between yield and seed N concentration in the three populations suggests that leaf senescence disrupts the negative correlation generally observed between these two traits.