Project description:Temperature is one of the most impactful environmental factors in response to which plants adjust their growth and development. While the regulation of temperature signaling has been extensively investigated for the aerial part of plants, much less is known and understood about how roots sense and modulate their growth in response to fluctuating temperatures. Here we found that shoot and root growth responses to high ambient temperature are negatively correlated during early seedling development. A shoot signaling module that includes HY5, the phytochromes and the PIFs exerts a central function in coupling these responses and triggers long-distance signaling to control root growth and auxin levels in the root. In addition to the HY5/PIF dependent shoot module, a local regulatory axis composed of auxin biosynthesis and auxin perception factors mediates root responses to high ambient temperature. Together, our findings uncover that roots integrate long-distance signals with local hormonal inputs during thermomorphogenesis.
Project description:Temperature is one of the most impactful environmental factors in response to which plants adjust their growth and development. While the regulation of temperature signaling has been extensively investigated for the aerial part of plants, much less is known and understood about how roots sense and modulate their growth in response to fluctuating temperatures. Here we found that shoot and root growth responses to high ambient temperature are negatively correlated during early seedling development. A shoot signaling module that includes HY5, the phytochromes and the PIFs exerts a central function in coupling these responses and triggers long-distance signaling to control root growth and auxin levels in the root. In addition to the HY5/PIF dependent shoot module, a local regulatory axis composed of auxin biosynthesis and auxin perception factors mediates root responses to high ambient temperature. Together, our findings uncover that roots integrate long-distance signals with local hormonal inputs during thermomorphogenesis.
Project description:Leaf-to-leaf, systemic immune signaling known as systemic acquired resistance (SAR) is poorly understood in monocotyledonous plants. Here, we characterize systemic immunity in barley (Hordeum vulgare) triggered after primary leaf infection with either Pseudomonas syringae pathovar japonica (Psj) or Xanthomonas translucens pathovar cerealis (Xtc). Both pathogens induced resistance in systemic, uninfected leaves against a subsequent challenge infection with Xtc. In contrast to SAR in Arabidopsis thaliana, systemic immunity in barley was not associated with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 or the local or systemic accumulation of salicylic acid (SA). Instead, we documented a moderate local but not systemic induction of abscisic acid (ABA) after infection of leaves with Psj. In contrast to SA or its functional analog benzothiadiazole, local applications of the jasmonic acid methyl ester or ABA triggered systemic immunity to Xtc. RNA-seq analysis of local and systemic transcript accumulation revealed unique gene expression changes in response to both Psj and Xtc and a clear separation of local from systemic responses. The systemic response appeared relatively modest and quantitative RT-PCR associated systemic immunity with the local and systemic induction of two WRKY and two ETHYLENE RESPONSIVE FACTOR-like transcription factors. Systemic immunity against Xtc was further associated with transcriptional changes after a secondary/systemic Xtc challenge infection; these changes were dependent on the primary treatment. Taken together, bacteria-induced systemic immunity in barley may be mediated in part by WRKY and ERF-like transcription factors possibly facilitating transcriptional reprogramming to potentiate immunity.
Project description:Transcriptome profiling (RNA-seq) of local and systemic tissue of Arabidopsis Col plants exposed to a local treatment of high light, heat stress and a combination of high light and heat stress on the same leafs or in different leaves