Rice plants detect insect-made RNA fragments to trigger defences, Nature study finds

A study published in Nature on 12 November describes a previously unknown way in which plants detect insect feeding and mount a defence. Researchers at the Center for Excellence in Molecular Plant Sciences (CEMPS), part of the Chinese Academy of Sciences, found that rice senses RNA breakdown products generated by an enzyme in the saliva of a herbivorous bug. The work was led by Chen Xiaoya, in collaboration with Wan Li's team, and the first author is Xiao-Xiang Guo.

A long-standing gap in plant immunity

Herbivorous insects release oral secretions while feeding. These contain digestive enzymes that break down plant macromolecules so that nutrients can be absorbed. The breakdown products could, in principle, act as signals that reveal the presence of an attacker, but how plants recognise such molecules and turn that recognition into a defence response has been poorly understood.

From insect enzyme to plant sensor

The team studied the rice green stink bug. During feeding, the insect secretes a T2 ribonuclease called NVR1 into plant tissue. The enzyme degrades RNA and produces 2′,3′-cyclic nucleotides (2′,3′-cNMPs). In rice, these molecules are perceived by NIB1, a glycine-rich RNA-binding protein.

Binding of the cyclic nucleotides promotes liquid–liquid phase separation of NIB1, a process in which proteins gather into dense, droplet-like assemblies. The result is the formation of condensates in the nucleus. These condensates recruit EDS1, a core regulator of plant immunity, and this recruitment activates downstream defence responses.

Potentially widespread across species

The authors point out that T2 ribonucleases are common in herbivorous insects, including the rice leaf folder, the green mirid and the cotton bollworm. Proteins related to NIB1 are also found widely across land plants. Taken together, this suggests the pathway may be a general strategy in plant–insect interactions rather than a quirk of one rice pest. The source does not report whether the mechanism has been tested in these other species, so the broader claim remains a hypothesis.

Why it matters and what comes next

For plant immunity researchers, the study links insect-derived RNA degradation products to a phase-separation-based sensing step, adding RNA-centred networks to the picture of how plants perceive and adapt to attack. It also shows a route by which a small, host-derived molecule can be converted into an immune signal inside the nucleus.

There is an applied angle as well. Applying these RNA degradation products from outside the plant was found to elicit defence responses, which points to possible use as immune activators in crop protection. The source gives no detail on field performance, effects on yield or insect outcomes, so such uses would need testing under agricultural conditions.

Open questions include whether NIB1 homologues in other crops respond in the same way, how widely insects rely on this enzyme, and whether pests can evolve ways to avoid producing or masking the signal. Answers would show how general this mechanism is and how far it can be exploited.

Reference: Guo X.-X. et al. A plant RNA-binding protein senses 2′,3′-cNMP produced by insect effectors. Nature (2026). DOI: 10.1038/s41586-026-11259-z

Source: Plant sensing mechanism guards against pests (Phys.org, 13 November 2026).

Image: AI-generated illustration.