Science1 publisher2 min readPublished
Engineered plant immune receptors cut bacterial growth about 53% in a model plant
NTU Singapore researchers cut bacterial growth about 53% in a model plant by clustering its immune receptors, with no reported cost to growth. The result is confined to a lab plant; each food crop would need its own receptors found and tested first.
The Scientist · Science desk
What happened
- NTU Singapore engineered Arabidopsis with a boosted immune system, and the plants grew about 53% fewer bacteria than unmodified controls in pathogen infection assays.
- The gain came from clustering the flagellin sensor FLS2 with its partner receptors, with two of each proving the optimum, found through single-molecule imaging and protein engineering.
- NTU has filed patents on two of the technologies through NTUitive and is now aiming the method at leafy vegetables and other crops suited to indoor farming.
Compiled by The ScientistSomething wrong?How this is made
Why it matters
- capability Boosting the plant's defenses did not cost it normal growth in the model, the property that would make the method worth carrying into crops.
- constraint The work sits in a lab model, so each target crop needs its own receptors identified, engineered and tested before any commercial use.
- exposure Indoor and vertical farms pack identical plants together, where a single pathogen can sweep the crop, so resistant seed shifts the risk there most.
The 53% is a bacterial count [2]. Researchers infected engineered plants and unmodified controls in pathogen assays and tallied the bacteria that grew, and the engineered plants carried roughly half as many [1]. The assay does not measure yield in a food crop. The plant tested was Arabidopsis thaliana, the standard laboratory model, chosen because its genetics and cell biology are well mapped [10]. The study appears in Science Advances [4].
FLS2, the receptor they engineered, sits on the cell surface and detects flagellin, a protein common to many bacteria [5]. Using single-molecule imaging and protein engineering, the team tried different groupings of FLS2 and its partner receptors, and two of each gave the strongest response the plant could keep up [6]. That renewal step matters: the arrangement raised immune signaling while still letting the receptors be cleared and replaced after they had done their job [7].
Adding more broke that. Extra receptors produced a strong first response but got in the way of their normal renewal, so the plant's long-term defense came out weaker [8]. Miao Yansong, the NTU biology professor who led the work, described it in terms of guards on a watchtower: "Our method is similar to putting more guards at a watchtower. Having the right number makes it easier to spot an intruder and respond quickly, but having too many can get in the way." [9]
The researchers report, without a figure, that the stronger response did not affect the plant's normal growth [3]. Arabidopsis is not a crop, though it belongs to the same family, Brassicaceae, as chye sim and kai lan [10]. The team says the same receptor principle could be adapted for leafy vegetables such as Chinese cabbage and kale [11], and that the receptors and their optimum arrangement would have to be identified, engineered and tested for each one before commercial use [12].
NTU has filed patent applications on two of the technologies through NTUitive, its commercialisation company [13]. Beyond seeds, the group is working on stimulants that could be sprayed on plants already growing to raise their immune response [14].
What to watch
- Whether the two-plus-two FLS2 arrangement reproduces in a leafy crop such as kale or chye sim, and at what growth cost.
- Any yield measurement from a food crop, which the Arabidopsis bacterial-count assay did not provide.
- Progress on sprayable stimulants meant to raise immunity in plants already growing.