The Xu laboratory uses tomato as research model to study how small peptide signaling and transcriptional condensation regulate developmental robustness and environmental resilience of plants, innovates rapid and precise breeding strategies for creating climate-smart crops.

Small peptide signaling and plant resilience
Cells must communicate over both short and long physiological ranges to ensure proper developmental patterning and functional connections. In plants, this can be achieved through small signaling peptides (SSP). While several SSPs have recently been characterized with vital roles in multiple biological processes, our understanding of plant small peptide signaling is still very limited (no more than 10% of plant small peptides signals have been functionally characterized) and hindered by many hurdles. Xu lab is developing novel strategies to fully reveal the landscape and impact of plant peptide signals in cell-to-cell communications, and their roles in controlling developmental robustness and stress resilience of plants.

Phase separation regulated cell-fate programming and reprogramming
The capacity of cells to acquire new fates is central to the development of multicellular organisms. How cells adopt different identities has been long fascinated biologists. Activation of transcription factors is a precisely controlled biological process that determines the gene-expression program characteristic of each cell type. Phase-separated condensates of the transcription apparatus at key cell-identity genes have been reported in mammalian cells but unknown in plants. Xu lab aims to elucidate how cellular and environmental cues induced liquid-liquid phase separation of plant transcription factors precisely control gene-expression pattern of cell-identity genes.

Climate-resilient crop innovation for sustainable agriculture
Global climate change and increasing human populations are creating an urgent need to improve crop productivity. Crop domestication and improvement by conventional methods often involves substantial inbreeding, which can lead to a loss of fitness due to the accumulation of deleterious genetic variants and loss of biological diversity. These challenges are calling for novel strategies to create nutritious and climate-smart crops. Rational design through precisely engineering or rewiring cellular processes such as photosynthesis and transcription machineries have shown great potential to improve crop productivity. Alternatively, de novo domestication of wild plants that are naturally endowed with stress tolerance or high nutrients by introducing desirable agronomic traits using genome editing have been shown practicable. Our research integrates multi-omics, genome editing and synthetic biology strategies to promote crop rational design and de novo domestication.