# A Secretory Protein Laccase lac8 From Pathogenic Fungi Activates Plant Protein 14‐3‐3 and Leucine‐Rich Repeat Receptor‐Like Protein LRR‐RLP1 to Trigger Mango Immunity

## TL;DR

A fungal protein called Cglac8 activates mango plant immunity by interacting with two plant proteins, offering new insights into plant-pathogen interactions.

## Contribution

The study identifies a novel defense mechanism in mango plants against fungal infection through the interaction of Cglac8 with MiLRR-RLP1 and Mi14-3-3-D1.

## Key findings

- Cglac8 interacts with MiLRR-RLP1 and Mi14-3-3-D1 to activate mango immunity.
- Overexpression of Cglac8, MiLRR-RLP1, and Mi14-3-3-D1 enhances mango resistance to the fungus.
- Cglac8 promotes phytohormone biosynthesis and reactive oxygen species burst in mango plants.

## Abstract

Plants cope with the biotic stress caused by pathogen infection through complex resistance mechanisms. Here, we identified a secreted laccase Cglac8 from Colletotrichum gloeosporioides and confirmed its involvement in C. gloeosporioides infection of mango (Mangifera indica) plants, as well as its ability to activate the host's innate immune mechanism. Cglac8 interacted with MiLRR‐RLP1 and Mi14‐3‐3‐D1 as demonstrated by yeast two‐hybrid, bimolecular fluorescence complementation and pull‐down assays. The interacting proteins MiLRR‐RLP1 and Mi14‐3‐3‐D1 positively regulate mango resistance to C. gloeosporioides by promoting the reactive oxygen species burst and biosynthesis of phytohormones. When Cglac8, MiLRR‐RLP1 and Mi14‐3‐3‐D1 proteins were overexpressed together in mango, the resistance of mango to C. gloeosporioides was significantly enhanced. Our findings reveal a new defence mechanism of host plants against C. gloeosporioides, providing a theoretical basis for disease‐resistant molecular breeding. The dual role of secretory laccase Cglac8 may reflect a balancing mechanism in host–pathogen co‐evolution.

A secreted laccase Cglac8 from Colletotrichum gloeosporioides targets host mango protein 14‐3‐3 and leucine‐rich repeat receptor‐like protein LRR‐RLP1 to trigger an immune response by promoting the biosynthesis of phytohormones.