Development of beneficial microbiome communities to increase the resistance against abiotic stress in Carica papaya and Capsicum annuum

Mexico, with Colima State as main producer, is the main exporter of Carica papaya and Capsicum annuum. Abiotic stress such as drought and heat are the major cause of fruit losses for both crops, a situation predicted to worsen under the prospect of changing climates. Enhancing crop productivity under changing climates is therefore of outermost importance to increase crop resilience against abiotic stresses. This requires new strategies that are more efficient and sustainable in protecting Carica papaya and Capsicum annuum against a broad range of abiotic stresses.
In nature, plants interact with complex microbial communities, known as microbiomes. Microbiomes include a broad spectrum of beneficial symbionts exhibiting a diversity of beneficial activities that can protect plants against environmental stresses. In fact, symbiont-mediated stress protection enabled plants to colonise land in the changing climates of the Mid-Palaeozoic era more than 400 million years ago. Ever since symbionts have been vital for stress resilience of plants in nature and developed protection mechanisms in co-evolution with plants. However, we just start to understand the true potential of microbiome members and their diverse activities in improving abiotic stress resilience in plants.
It is known that plants and soil contribute to the composition of microbial communities, and that the root microbiota acts to extend the capacity of plants to deal with stress. In previous proof of concept experiments, we identified microbes from both crops with stress-protecting activities. In this project, we want to exploit the bioprotective potential of microbiomes of Carica papaya and Capsicum annuum as a currently untapped resource that can equip us with sustainable and highly effective stress resilience agents. By conducting a systematic approach, we will determine the composition of different microbiomes associated with Carica papaya and Capsicum annuum. Using a combination of different Carica papaya and Capsicum annuum varieties and abiotic stress conditions we will generate a comprehensive microbe culture collection. This collection will build a resource for determining the diverse bio-protecting activities of microbiome members using a series of defined biochemical and functional assays. In collaboration with industry partners we will develop solutions to apply our findings as a strategy to sustainably enhance abiotic stress resilience in Carica papaya and Capsicum annuum.

This project will support existing collaborations with agri-tech industry and benefit the public. The findings made in this project represent an innovative strategy to identify and apply microbes as plant stress-protecting agents. Together with agri-tech industry (project partner Caribbean Seed Company and AltusBiopharm ) we will identify solutions to apply our findings as part of the project that will help farmers to enhance abiotic stress tolerance in the field. We will further interact with stakeholders to emphasise the potential of stress-protecting plant microbes as a currently untapped resource to identify novel and innovative ways to increase agricultural crop productivity and, hence, sustain food security.
Agri-tech industry and farmers
Environmental threats such as drought and heat stress are most devastating in modern agriculture. These threats are increasing as climate changes, both in potency and unpredictability and are difficult, in some cases impossible, to control. Plants have the ability the change the microbiome to recruit beneficial microbes from surrounding soils. Mutualistic interactions between plants and microbes thus offer a natural alternative to enhance crop stress resilience. If farmers could utilise the natural microbial relationships of beneficial fungi that promote growth and stress resistance more successfully, it could significantly stabilise crop productivity under changing climates. In addition, it would bring a range of environmental and cost savings to farmers and the public. For example it would serve a more sustainable agricultural productivity and also reduction in food miles to due higher efficiency farming methods. Importantly, our findings could be applied to agriculture in developing countries, bringing the same range of cost and environmental benefits to a large number of people under increasing food and economic poverty.
We specifically focus on the identification of abiotic stress-protecting microbes for Carica papaya and Capsicum annuum as economically most important crops in Colima State, Mexico. If we can enhance root adaptation and plasticity to environmental cues by vaccinating crops with stress-protecting microbes and microbial communities we could provide food security solutions to forward a new green revolution. Individual members and small sub-communities of plant-associated microbiomes represent a currently unused resources to develop sustainable crop stress protection strategies. For instance, our studies indicate that Serendipita indica can improve abiotic stress protection in an apparently unlimited number of crops by 10-20%. Our agri-tech industry partners Caribbean Seed Company and AltusBiopharm are deeply interested in commercialising our research outcomes and they are active project partners and investors in the project. We will have regular meetings with them to discuss strategies to apply and commercialise our findings.
The public
Overall, the knowledge generated in this project aims at developing crops with an improved abiotic stress resilience under ever-increasing stress conditions, as expected from future climate change. Sustaining food security as a long-term aim initiated by this project will therefore serve the public. To communicate our ideas of crop improvement to a broader community we will engage with the public and especially with pupils to develop an awareness of our strategies to address challenges in future crop production.