Holistic understanding of xylem recovery from water stress to mitigate future climate impact on woody plants

Water under tension can be described as being in a metastable state where small disturbances can lead to cavitation i.e. the formation of vapor voids in the liquid. These voids can expand in vessels causing embolism that blocks water transport as no more tensile strength can be transduced through the embolus and no water could be pulled up to the top of the plant.
A reduction in productivity or plant death may result. It has been demonstrated that many plant species counter embolism formation with a refilling processes that can occur despite the presence of moderate tension.

Currently, we lack an understanding of the biology behind the refilling process, although several proposals and comprehensive hypotheses of how this might happen have been investigated and proposed. However, despite these efforts the mechanism responsible for embolism refilling under negative pressure is still not well understood.

In particular, no systematic research has yet been focused on:

• metabolic processes and membrane protein activity involved in the plant response to embolism that can lead to restoration of hydraulic capacity
• role of gene expression in these processes.

• to determine the biological activity of plant vessels/parenchyma complex during xylem embolism formation and subsequent restoration of hydraulic conductivity under different climate conditions
• to characterize the key genes triggering tolerance mechanisms to embolism.

Insights
PlantStressLab
PlantStressLab - MITIWOOD
PlantStressLab - Xylem Refilling

• PlantStressLab - MITIWOOD
• PlantStressLab - Xylem Refilling.

• Secchi F., Pagliarani C., Cavalletto S., Petruzzellis F., Tonel G., Savi T., Tromba G., Obertino M.M.,  Lovisolo C., Nardini A., Zwieniecki M. (2021). Chemical inhibition of xylem cellular activity impedes the removal of drought-induced embolisms in poplar stems – new insights from micro-CT analysis. New Phytologist 229:820-830
• Morabito C., Orozco J., Tonel G., Cavalletto S., Meloni G.R., Schubert A., Gullino M.L., Zwieniecki M.A., Secchi F. (2021). Do the ends justify the means? Impact of drought progression rate on stress response and recovery in Vitis vinifera. Physiologia Plantarum 164:54-62
• Pagliarani C., Casolo V., Ashofteh Beiragi M., Cavalletto S., Siciliano I., Schubert A., Gullino M.L., Zwieniecki M.A., Secchi F. (2019). Priming xylem for stress recovery depends on coordinated activity of sugar metabolic pathways and changes in xylem sap. PCE doi: 10.1111/pce.13533
• Petruzzellis F., Pagliarani C., Savi T., Losso A, Cavalletto S., Tromba G., Dullin C., Bär A., Ganthaler A., Miotto A., Mayr S., Zwieniecki M., Nardini A., Secchi F. (2018). The pitfalls of in vivo imaging techniques: evidence for cellular damage caused by synchrotron X-ray computed micro-tomography. New Phytologist 220: 104-11
• Secchi F., Pagliarani C., Zwieniecki M.A. (2017). The functional role of xylem parenchyma cells and aquaporins during recovery from severe water stress. Plant Cell and Environment 40: 858-871. doi: 10.1111/pce.12831