Grafting trick could let us gene-edit a huge variety of plants – New Scientist

Report on a Novel Gene-Editing Technique via Grafting to Advance Sustainable Development Goals

1.0 Introduction: Agricultural Innovation for Global Sustainability

A novel plant modification technique utilizing grafting has been developed, presenting a significant opportunity to advance key United Nations Sustainable Development Goals (SDGs). This method enables the application of CRISPR gene editing to a wider range of plant species, including those previously considered difficult or impossible to edit. By improving crop productivity, nutritional value, and resilience, this innovation directly addresses global challenges outlined in the 2030 Agenda for Sustainable Development, particularly those related to food security, climate action, and sustainable production.

2.0 Challenges in Conventional Gene Editing and SDG Implications

Current gene-editing methodologies in agriculture face significant limitations that impede progress toward several SDGs. These challenges hinder the development of crops needed to achieve a sustainable future.

• Technical Barriers: Conventional methods, such as biolistics and Agrobacterium-mediated transformation, are ineffective for many economically and nutritionally important species, including coffee, cocoa, cassava, and avocados. This technological gap slows progress on SDG 2 (Zero Hunger) by limiting improvements to staple food sources.
• Regulatory Hurdles: Existing techniques often insert foreign DNA into the plant’s genome, classifying the resulting organism as a traditional Genetically Modified Organism (GMO). This triggers lengthy and costly regulatory approval processes, delaying the deployment of climate-resilient and higher-yield crops essential for SDG 13 (Climate Action) and SDG 12 (Responsible Consumption and Production).
• Inefficiency: The reliance on regenerating whole plants from single modified cells is a major bottleneck, restricting the application of precision breeding to a limited number of cultivars.

3.0 The Grafting-Mediated Gene-Editing Methodology

The new approach circumvents previous limitations by combining the ancient practice of grafting with modern biotechnology. The process is designed to deliver gene-editing tools without permanently integrating foreign DNA into the target plant.

1. Rootstock Engineering: A compatible rootstock plant is genetically engineered to produce mobile RNA molecules. These RNAs code for the essential components of the CRISPR system: the Cas editing protein and the specific guide RNA that targets a gene for modification.
2. Grafting Process: A shoot (scion) from a non-modified elite plant variety is grafted onto the engineered rootstock.
3. Systemic RNA Transport: The mobile RNAs produced in the rootstock travel through the plant’s vascular system into the cells of the grafted shoot.
4. Targeted Gene Editing: Once inside the shoot’s cells, the RNAs are translated into the CRISPR machinery, which performs the precise, targeted gene edit. The resulting edits in the shoot and its subsequent seeds are heritable, but the plant itself contains no foreign DNA, aligning with streamlined regulatory pathways.

4.0 Contributions to Sustainable Development Goals

This innovative technique offers a powerful tool to accelerate progress across multiple SDGs by fostering a more sustainable and resilient global food system.

• SDG 2: Zero Hunger: By enabling the genetic improvement of staple crops like cassava and high-value crops like coffee and avocado, this method can increase yields, enhance nutritional content, and secure food supplies for a growing global population.
• SDG 13: Climate Action: The technology facilitates the rapid development of climate-resilient crops that can withstand the impacts of climate change, such as drought, extreme temperatures, and new diseases. This is a critical adaptation strategy for global agriculture.
• SDG 12 & SDG 15 (Responsible Production & Life on Land): Creating crops with enhanced disease resistance can reduce the reliance on chemical pesticides, contributing to more sustainable production patterns and protecting terrestrial ecosystems. Higher-yielding crops can also reduce the pressure to convert natural habitats into agricultural land.
• SDG 9: Industry, Innovation, and Infrastructure: This breakthrough represents a significant scientific innovation that can transform the agricultural industry. A single engineered rootstock can serve as a universal tool to edit multiple varieties and even related species, promoting widespread and sustainable technological upgrading in the sector.

5.0 Future Prospects and Strategic Potential

The potential applications of this grafting-based system are extensive. A single transgenic rootstock could be maintained and used indefinitely to edit a wide array of elite crop varieties, significantly reducing the effort and cost of crop improvement. Researchers envision combining this rootstock delivery system for the large Cas protein with viral vectors to deliver smaller, easily interchangeable guide RNAs. This synergistic approach would create a highly flexible and efficient platform for making diverse genetic improvements, positioning it as a cornerstone technology for achieving a sustainable and food-secure future in line with the SDGs.

1. Identified Sustainable Development Goals (SDGs)

The article discusses a new agricultural technology aimed at improving crop resilience and productivity to address global challenges like food security, climate change, and the need for sustainable farming. Based on these themes, the following SDGs are addressed:

• SDG 2: Zero Hunger: The core focus of the article is on making plants “more productive and more nutritious” to feed a “growing world population” and limit “food price hikes,” which directly relates to ending hunger and ensuring food security.
• SDG 9: Industry, Innovation and Infrastructure: The article is centered on a scientific innovation—using grafting for gene editing—and highlights its potential. It describes a new technique developed by researchers and encourages others to “help develop it,” which aligns with promoting scientific research and technological advancement.
• SDG 13: Climate Action: The technology is presented as a solution to the problem of “climate change increasingly hits yields.” By creating more resilient crops, this innovation helps in adapting to the impacts of climate change on agriculture.

2. Specific Targets under Identified SDGs

SDG 2: Zero Hunger

• Target 2.3: By 2030, double the agricultural productivity and incomes of small-scale food producers…

  The article directly supports this target by focusing on a technique to make “plants more productive.” The development of improved varieties of crops like “cassava,” a staple for many small-scale farmers, implies a direct impact on agricultural productivity.

• Target 2.4: By 2030, ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production… and strengthen capacity for adaptation to climate change…

  The article describes creating plants with traits like “disease resistance” and the ability to withstand the effects of “climate change increasingly hits yields.” This new grafting and gene-editing method is a clear example of a resilient agricultural practice designed to ensure sustainable production in the face of environmental stress.

• Target 2.5: By 2030, maintain the genetic diversity of seeds, cultivated plants…

  The technique allows for gene editing in plants that were previously difficult or impossible to modify, such as “cocoa, coffee, sunflowers, cassava or avocados.” By enabling precise edits in a wider range of plants, including “all sorts of elite varieties,” the technology helps enhance and utilize the genetic diversity of cultivated plants.

SDG 9: Industry, Innovation and Infrastructure

• Target 9.5: Enhance scientific research, upgrade the technological capabilities of industrial sectors in all countries… encouraging innovation…

  The entire article is a report on a scientific breakthrough. It describes a novel approach that combines an “ancient trick” of grafting with modern CRISPR gene editing. The call to action for other scientists to “help develop it” and the description of it as a technique with “great potential” directly embodies the spirit of enhancing scientific research and fostering innovation.

SDG 13: Climate Action

• Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.

  The article explicitly states that a key motivation for this research is that “climate change increasingly hits yields.” The development of crops that are more resilient to climate-induced stress is a direct measure to strengthen the adaptive capacity of agricultural systems, which are highly vulnerable to climate-related hazards like droughts and extreme weather.

3. Indicators for Measuring Progress

Indicators for SDG 2 Targets

• For Target 2.3: The article implies the use of crop yield and productivity metrics. The success of the technology would be measured by the increase in production of staple crops like cassava or commercial crops like coffee, as mentioned in the text.
• For Target 2.4: An indicator is the number of new crop varieties developed with resilient traits. The article mentions creating a “Chardonnay gene editing rootstock conferring, say, disease resistance,” which can be quantified as a measure of progress.
• For Target 2.5: A relevant indicator is the number of plant species and varieties made amenable to gene editing. The article highlights that the technique works for previously inaccessible plants like “cocoa, coffee, sunflowers,” so tracking the expansion of this list would measure progress.

Indicator for SDG 9 Target

• For Target 9.5: Progress can be measured by the level of research and development activity in this specific field. The article itself, being a scientific report, and the call for collaboration (“encouraging others to help develop it”) suggest that indicators could include the number of research publications, patents filed, or collaborative projects initiated based on this technique.

Indicator for SDG 13 Target

• For Target 13.1: An indicator would be the development and deployment of climate-resilient crop varieties. The article’s focus on mitigating how “climate change increasingly hits yields” implies that success would be measured by the creation of crops that can maintain stable yields despite adverse climate conditions.

4. Summary Table of SDGs, Targets, and Indicators

Source: newscientist.com