The ReLEAF team in their team shirts walking in single file between bean trellises on Farmer Chen’s farm in Tamsui, with Chen at the head of the line.

Every Farmer a Biomanufacturer

Empowering future farmers to combat climate change with a Stress-Responsive Optogenetic Bioreactor for Precision Plant Protection

As long as it benefits the plants and does not disrupt the balance of nature, I am very willing to try any new technology. This gives me more time to do what I love most — farming.

Farmer Huiwen ChenTamsui, Taiwan · July 21, 2026

Farmer Chen

Farmer Chen in Tamsui told us how climate stress directly affects crop health and yield.

Map: close on Tamsui, at the mouth of the Tamsui River on the north coast.
Climate volatility

0.29 °Cof warming per decade since 1991

Her experience reflects a larger pattern across Taiwan, where heat stress is becoming an increasing challenge for agriculture.

Climate volatility index0.380.490.600.710.820.93

Map: the western plain from Taichung to Tainan is in the two most volatile classes; the north, the mountains, the east and the far south are lower.
Small-scale farmers

99.2%of Taiwan’s farms are under 2 hectares

Together they work 85.3% of its farmland, most of it along the western plain and in the south.

Farmland

Map: the farmland of the western plain, from Taichung to Kaohsiung.
Where they overlap

The challenge becomes greatest where agricultural production and climate vulnerability overlap.

Volatility, on the farmland0.380.490.600.710.820.93

Map: the farmland of the western plain from Yunlin to Tainan is in the two most volatile classes.
Even when farmers see the stress, protection can still remain out of reach.

Protectants exist, but they are often too far, too slow, or too inaccessible for small-scale farmers.

Volatility, on the farmland0.380.490.600.710.820.93

Map: the whole island, its farmland coloured by climate volatility.

How can we empower farmers to
detect stress earlier and access protection in time?

We believe the answer has to meet five demands.

Protective
On demand
Automated
Biosafe
Monitored

ReLEAF

From stress prediction, protein production, separation and delivery in one integrated system.

The bench circulation loop with its in-line photometer, in a glass-fronted cabinet: a media bottle of yellow B. subtilis culture on a stirrer, the peristaltic pump, the black photometer tower and a breadboard, with plants on the shelf above.

How ReLEAF works

Predict local stress A leaf sensor monitors leaf temperature and wetness, which combines with the weather forecast. Our predictive AIoT model then turns the data into a stress index to predict when stress will become too high for the crop.
Green light activation When predicted stress approaches the threshold, the system activates 520 nm green light, switching on the CcaSR optogenetic circuit in engineered B. subtilis.
Produce the protectant The engineered B. subtilis responds to the light signal by producing plant-protective proteins inside the bioreactor.
Retain the bacteria, release the product The culture circulates through a hollow-fiber membrane that retains the engineered bacteria while allowing smaller soluble protectants to pass into the product stream.
Delivery to the crop The protectant stream is designed to connect with hydroponic circulation or soil irrigation, bringing protection closer to the crop before stress causes greater damage.
Switch off production Once the predicted stress has passed, 660 nm red light switches the circuit off again, reducing unnecessary protein production and metabolic burden.