A damaged plant can heal itself. A broken stem produces side shoots, and a pruned bush grows back denser. One might assume the plant simply floods the injured area with its sweet nutrients. But it is not that simple. Animals can dilate blood vessels and direct fuel to a wound, but a plant cannot alter its vascular system.
A new study tracked the movement of this fuel in a healing wound and discovered that the plant unexpectedly uses the sugar it contains. The findings were published in the journal bioRxiv.
Tissue repair is one of the most energy-intensive processes for a plant. New cells divide and grow rapidly, burning sugar—the fuel the plant produces through photosynthesis. Delivering this fuel to the damaged site is the most challenging task.
This puzzle intrigued Idan Efroni, a plant biologist at the Hebrew University of Jerusalem (HUJI), and Rotem Matosevich, a graduate student in his lab. They worked with Arabidopsis thaliana, a small plant from the mustard family widely used in plant research.
To begin, they cut off the tip of the root, its growth zone, and observed its recovery. Removing leaves or blocking photosynthesis with chemicals slowed the healing process. When they fed the plant sugar again, the root tip healed.
Cutting off the root tip seems fatal, yet, as previous experiments showed, the stump regenerates the entire growth point within a few days. The real question was where the sugar went during this time.
They tracked sucrose, the main sugar the plant transports, using a glowing substitute. In a healthy root, it flowed directly to the tip. After cutting, it stopped, accumulating outside the area trying to regrow.
This created a contradiction. Sugar from the leaves was clearly necessary, but the plant’s primary transport sugar did not enter the damaged tissue. Something else had to deliver the fuel for the final leg of the journey to the injured cells.
Searching for the missing element, the team borrowed Glifon—a glowing sensor originally developed to track sugar inside animal and human cells. In plants, it lights up where this sugar accumulates. The marker, indicating glucose—a simpler sugar than sucrose—remained dim on the healthy wound tip, then, as healing progressed, lit up as a bright band below the cut. The glow intensified over the first day.
Before this work, no one had observed such a redistribution of sugar inside living, healing tissues. The plant did not flood the wound with its usual sugar. Instead, it gathered a different sugar—glucose—at the site where new cells were forming.
This process appears to be driven by a rapid genetic response. Within hours of the cut, the plant activates genes around the wound, before the new cells even begin to run out of fuel. These genes create part of the machinery needed to redirect the sugar.
The system operates based on two components. One is an enzyme that breaks down sucrose into glucose between cells, a step previously linked to attracting sugar to tissues in need, as explained in one review. The other mechanism is a pump that moves the released glucose into the recovering cells.
Together, they act as a sugar trap. By converting sucrose into glucose and pulling it inside, they keep sugar levels low in cells near the wound, which, the researchers believe, directs the plant’s sugar reserves to the repair site. The fuel reaches the damaged area without moving the plant’s stationary pipelines.
To test whether this mechanism actually promotes healing, the team disabled the genes one by one. Plants without them struggled to recover, especially under sugar-scarce conditions, a common situation in the wild.
The reverse scenario was even more striking. Extra copies of one gene responsible for sugar import allowed plants to recover faster, using much less fuel, and achieve full recovery with about a third of the sugar needed by normal plants.
However, there was a limit. More fuel did not always mean better. Pushing the importer too hard slowed repair again. It seems the system is tuned to a narrow operating range.
Even the timing was telling. The genes responsible for sugar processing activated within hours of the cut, long before the plant ran out of fuel a day or two later. The system was set up in advance, not assembled after the cells began to starve.
The system treats damage not so much as an emergency to react to, but as a need it prepares for, deliberately managing its limited fuel reserves.
The same strategy appeared with a completely different type of injury. If the entire root system of a seedling is removed, it starts growing new roots from the base of the stem, with the same genes activating around the damaged area.
This study establishes something concrete. A damaged plant does not distribute sugar evenly. Instead, it quickly and purposefully creates a hotspot of glucose concentration at the injury site, altering the sugar transport mechanism. Activating this system speeds up healing.
This opens up practical possibilities. Crops are constantly subjected to physical stress from storms, insects, and machinery, and often must recover with a limited energy budget during drought or heat. A system that uses fuel more efficiently could recover faster.
The glowing sensor itself is a breakthrough. For the first time, researchers can observe sugar movement in a living plant and see where it accumulates, raising new questions about how plants allocate energy during growth and recovery.
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