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Greb, T.

Publications and source records attributed to Greb, T..

2 recordsLinked to original sources

A Comprehensive Tool Set for Inducible, Cell Type-Specific Gene Expression in Arabidopsis

Understanding the context-specific role of gene function is a key objective of modern biology. To this end, we generated a resource for inducible cell-type specific trans-activation based on the well-established combination of the chimeric GR-LhG4 transcription factor and the synthetic pOp promoter. Harnessing the flexibility of the GreenGate cloning system, we produced a comprehensive set of GR-LhG4 driver lines targeting most tissues in the Arabidopsis shoot and root with a strong focus on the indeterminate meristems. We show that, when combined with effectors under control of the pOp promoter, tight temporal and spatial control of gene expression is achieved. In particular, inducible expression in F1 plants obtained from crosses of driver and effector lines allows rapid assessment of the cell type-specific impact of an effector with high temporal resolution. Thus, our comprehensive and flexible toolbox is suited to overcome the limitations of ubiquitous genetic approaches, the outputs of which are often difficult to interpret due to widespread existence of compensatory mechanisms and the integration of diverging effects in different cell types.\n\nOne sentence summary: A set of lines enabling spatio-temporal control of gene expression in Arabidopsis.

plant biology

Spatial Specificity Of Auxin Responses Coordinates Wood Formation

Spatial organization of signaling events of the phytohormone auxin is fundamental for maintaining a dynamic transition from plant stem cells to differentiated descendants. The cambium, the stem cell niche mediating wood formation, fundamentally depends on auxin signaling but its exact role and spatial organization is obscure. Here, we show that, while auxin signaling levels increase in differentiating cambium descendants, a moderate level of signaling in cambial stem cells is essential for cambium activity. We identify the auxin-dependent transcription factor ARF5/MONOPTEROS to cell-autonomously restrict the number of stem cells by attenuating the activity of the stem cell promoting WOX4 gene. In contrast, ARF3 and ARF4 function as cambium activators in a redundant fashion from outside of WOX4-expressing cells. Our results reveal an influence of auxin signaling on distinct cambium features by specific signaling components and allow the conceptual integration of plant stem cell systems with distinct anatomies.

plant biology