Periodic Reporting for period 2 - APHIDTRAP (Understanding and Preventing Plant Susceptibility to Aphids)
Reporting period: 2022-12-01 to 2024-05-31
Aphids are phloem-feeding insects that can cause significant damage to crops worldwide, posing a major threat to global food security. Crucially, there is a lack of effective genetic crop resistance against aphids, and the most common method of control is through the use of insecticides. However, insecticides are costly and can harm the environment. Moreover, aphids can develop resistance to them. These insects can deliver proteins to host plants, called effectors, which suppress the plant immune system and promote susceptibility. Recent research has discovered that these aphid effectors interact with host plant proteins in a similar way to effectors from plant pathogenic microbes. This raises important new questions that require immediate attention to develop novel and sustainable protection strategies against aphids. These questions are:
What is the mechanistic and structural basis of aphid effector-triggered susceptibility?
How can we prevent or interfere with aphid effector-triggered susceptibility?
APHIDTRAP will address these questions using an innovative strategy based on the following objectives:
1) We will introduce a structural biology approach to the insect effector biology field to reveal protein 3D structures of aphid effectors and their host protein targets and determine how mutations in these proteins affect interactions and protein functions.
2) We will use both natural variants and mutants of effectors and host protein targets, combined with in planta functional assays to explore plant-aphid molecular co-evolution.
3) We will identify host protein target interactomes and investigate how mutations affect network functionality.
4) We will use the information generated in 1-3 to develop and apply a synthetic biology approach to prevent aphid effector-triggered susceptibility in plants.
What is the mechanistic and structural basis of aphid effector-triggered susceptibility?
How can we prevent or interfere with aphid effector-triggered susceptibility?
APHIDTRAP will address these questions using an innovative strategy based on the following objectives:
1) We will introduce a structural biology approach to the insect effector biology field to reveal protein 3D structures of aphid effectors and their host protein targets and determine how mutations in these proteins affect interactions and protein functions.
2) We will use both natural variants and mutants of effectors and host protein targets, combined with in planta functional assays to explore plant-aphid molecular co-evolution.
3) We will identify host protein target interactomes and investigate how mutations affect network functionality.
4) We will use the information generated in 1-3 to develop and apply a synthetic biology approach to prevent aphid effector-triggered susceptibility in plants.
Towards 1) we have developed and applied an AI-based computational pipeline for aphid effector structure prediction. Computational analyses of a set of 71 aphid effectors from the species Myzus persicae (green peach aphid) predicted protein functions and showed that a significant number of these proteins are disordered (i.e. they lack a homogenous ordered three-dimensional structure). This pipeline has helped us prioritise proteins for further studies using wet-lab experimental approaches. We have set up a wet-lab structural biology pipeline which we are currently using to reveal the structures of a subset of 6 effectors and in several cases their plant targets. We also developed an improved structural prediction pipeline which we have used to predict ligand binding of aphid effectors.
Towards 2) we have performed extensive structure-function analyses for two effector-target interactions of interest to understand how these proteins interact with one another to be able to explore strategies to ultimately disrupt interactions. In part these analyses were guided by computational structure predictions performed under 1). Our results point to specific protein regions required for effector-target interaction and mutagenesis approaches combined with functional assays are currently being used to explore the importance of these specific protein regions in susceptibility in more detail.
Towards 3) we have generated essential experimental resources and optimised protocols to identify effector target networks in plants.
Towards 4) we have set up a screening platform that will help us to identify molecules that bind with high affinity to aphid effectors of interest. In addition, we have set up a CRISPR-Cas9 gene editing for effector targets of interest which will allow us to determine if disruption/mutation of targets will reduce plant susceptibility, thereby providing protection against infestation.
Towards 2) we have performed extensive structure-function analyses for two effector-target interactions of interest to understand how these proteins interact with one another to be able to explore strategies to ultimately disrupt interactions. In part these analyses were guided by computational structure predictions performed under 1). Our results point to specific protein regions required for effector-target interaction and mutagenesis approaches combined with functional assays are currently being used to explore the importance of these specific protein regions in susceptibility in more detail.
Towards 3) we have generated essential experimental resources and optimised protocols to identify effector target networks in plants.
Towards 4) we have set up a screening platform that will help us to identify molecules that bind with high affinity to aphid effectors of interest. In addition, we have set up a CRISPR-Cas9 gene editing for effector targets of interest which will allow us to determine if disruption/mutation of targets will reduce plant susceptibility, thereby providing protection against infestation.
By the end of this project, we aim to have elucidated novel mechanisms that underlie susceptibility to aphids. Specifically, we aim to provide novel insights into how aphid effector proteins interact with and modify plant targets and use this knowledge to provide proof-of-concept for a novel form of crop resistance based on preventing aphid effector-mediated susceptibility. The development of such novel crop resistances will positively impact future crop improvement strategies aimed at increasing crop yields while reducing the use of environmentally damaging pesticides.