Research Fields and Interests

Although plants do not have a central sensing and distribution system, communication between cells and tissues is evident. This communication system is essential for orchestrated development of distant organs and responses to developmental and environmental cues. For example, signaling between the root, which takes up water and micronutrients, and the photosynthetic shoot system is essential to ensure proper allocation of resources and coordinated adaptation to local growth conditions. Changes in day length that are sensed in leaves lead to the decision to flower in the remote shoot apex. An important component of coordinated growth behavior must therefore be the transmission of information over long distances. Systemic signals inform remote organs to adapt their growth to environmental cues.

The plant vascular system is composed of two distinct tissues; the xylem and the phloem. The xylem serves to conduct water, minerals and growth substances from the roots to the above ground plant tissues. The phloem system delivers photoassimilates and amino acids from photosynthetically active leaves (sources) to various heterotrophic sink organs such as roots and flowers, fruits or seeds. It is now evident that in addition to sugars and nutrients, the phloem also transfers a distinct population of RNA molecules and proteins to distant organs. Grafting experiments have established that a number of these macromolecules are capable of moving long distances into distinct plant parts, thus providing support for the operation of a phloem-mediated inter-organ communication network.

The major goal of our research is to decipher the long-range communication code in plants. Specifically, we study the biological role of long-distance trafficking macromolecules and how environmental cues affect signal translocation between remote organs.

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