In Brachypodium a complex signaling is actuated to protect cells from proteotoxic stress and facilitate seed filling
Autor: | Federica Brandizzi, Curtis G. Wilkerson, Sang Jin Kim, Starla Zemelis-Durfee |
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Rok vydání: | 2017 |
Předmět: |
0106 biological sciences
0301 basic medicine Hot Temperature RNA Splicing Plant Science Biology 01 natural sciences Article Endosperm 03 medical and health sciences Gene Expression Regulation Plant Botany Genetics Storage protein Transcription factor chemistry.chemical_classification Kinase Endoplasmic reticulum food and beverages Endoplasmic Reticulum Stress biology.organism_classification Mixed-linkage glucan Cell biology 030104 developmental biology chemistry Seeds Unfolded Protein Response Unfolded protein response Brachypodium Signal Transduction Transcription Factors 010606 plant biology & botany |
Zdroj: | Planta. 246:75-89 |
ISSN: | 1432-2048 0032-0935 |
Popis: | A conserved UPR machinery is required for Brachypodium ER stress resistance and grain filling. Human and livestock diets depend on the accumulation of cereal storage proteins and carbohydrates, including mixed-linkage glucan (MLG), in the endosperm during seed development. Storage proteins and proteins responsible for the production of carbohydrates are synthesized in the endoplasmic reticulum (ER). Unfavorable conditions during growth that hamper the ER biosynthetic capacity, such as heat, can cause a potentially lethal condition known as ER stress, which activates the unfolded protein response (UPR), a signaling response designed to mitigate ER stress. The UPR relies primarily on a conserved ER-associated kinase and ribonuclease, IRE1, which splices the mRNA of a transcription factor (TF), such as bZIP60 in plants, to produce an active TF that controls the expression of ER resident chaperones. Here, we investigated activation of the UPR in Brachypodium, as a model to study the UPR in seeds of a monocotyledon species, as well as the consequences of heat stress on MLG deposition in seeds. We identified a Brachypodium bZIP60 orthologue and determined a positive correlation between bZIP60 splicing and ER stress induced by chemicals and heat. Each stress condition led to transcriptional modulation of several BiP genes, supporting the existence of condition-specific BiP regulation. Finally, we found that the UPR is elevated at the early stage of seed development and that MLG production is negatively affected by heat stress via modulation of MLG synthase accumulation. We propose that successful accomplishment of seed filling is strongly correlated with the ability of the plant to sustain ER stress via the UPR. |
Databáze: | OpenAIRE |
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