We've worked with our scientists to answer the questions we get asked most often about gene technologies, how they work and how they might be used in growing food.

What is a gene?

A gene is a sequence of DNA that can be inherited through generations. A gene usually encodes a function within an organism (plant, animal or microbe). The DNA stores information used to create a protein or an RNA that carries out the function. These functional molecules give rise to the various characteristics, or traits, of the organism. Some traits are encoded by a single gene, but most need many genes working together.

Each gene is made up of a long series of four DNA building blocks. Called ‘bases’ these are usually represented by the letters A, T, G and C. Some genes naturally come in slightly different versions, where a few bases out of hundreds or thousands, are different. These are called alleles and can result in quite dramatic differences to the gene function and final trait.

Most organisms inherit one allele from their father and one from their mother (some plants can inherit multiple copies) for each of their genes. This is one of the reasons no two organisms, even siblings, look quite the same.

What is a genome?

A genome is the complete DNA sequence of an organism. A reference genome for an organism is based on the DNA sequence of a specific individual. More detailed genome sequences identify the bases or areas of the DNA that differ most often between individuals of the same species, such as the sequences of different alleles of a gene.

Having the genome sequence of an organism doesn’t mean that scientists have also identified all the genes. The genome sequence includes a lot of DNA that isn’t part of genes, so other experiments are required to identify where a specific gene sits within the sequence, known as gene mapping.

Plant & Food Research has been involved in the genome sequencing of a number of plants of importance to New Zealand, including apple, kiwifruit, potato, blueberry, bilberry, mānuka, swamp maire and rewarewa.

What is traditional plant breeding?

Traditional plant breeding is when two plants are identified with desired traits and chosen as parents for a breeding cross. The pollen, holding the male contribution to the reproductive process, is collected from the flowers of one parent and applied to the female parts of a flower of the other parent. The resulting seeds are collected and tested to see which have the best combination of the desired traits from each of their parents.

What are new breeding technologies?

New breeding technologies (NBTs) are techniques where the DNA of an organism is altered by scientists in a targeted and precise way. These include gene editing, base editing and prime editing. There is often no way to identify if new breeding technologies have been used in the breeding of a new organism - the small changes in the DNA of the organism look the same as those that occur in nature, such as when DNA changes, known as variants or mutations, have occurred through exposure to UV light, for example.

What is gene editing?

Gene editing is a technique where a change to the DNA of an organism is triggered at a specific point in the DNA by causing a cut and repair of the DNA sequence.

Gene editing with CRISPR is the most commonly used new breeding technology. CRISPR editing uses an enzyme that can be ‘programmed’ to find and cut a DNA sequence at a very specific point. When the DNA is cut, the cell’s normal repair system activates. If this system makes a mistake during the repair and replaces one of the bases with a different one, the new DNA sequence may create an alternative allele of the gene and a different version of the trait.

CRISPR can also be used to make more complex gene edits, where parts of the DNA sequence are removed at the cut point or new DNA sequences are embedded.

How does gene editing differ from other forms of genetic modification?

Traditional genetic modification is a technique where the DNA of an organism is altered by scientists through the permanent addition of DNA from another source. This DNA may have come from the same species (cisgenic) or another species (transgenic). New gene editing techniques involve the alteration of an organism’s own existing DNA using the cell’s own DNA repair systems without the addition of external DNA.

What is the process of gene editing a plant?

The gene editing process has a number of steps:

Scientists are investigating how to gene edit plants without the need for introducing a transgene, which would simplify step 2.

The process of gene editing a plant cell takes several hours and it can take a year to grow the cell into a whole plant (this varies from plant to plant). However, the research required to be able to successfully gene edit a cell and grow it into a whole plant can take many years.

There are a number of technical, legal and regulatory barriers that need to be addressed before a gene edited plant can be developed, including having the rights to edit the selected gene and plant, and knowing the factors required to grow the cell into a whole plant.

How could gene editing speed up the plant breeding process?

Gene editing a plant would allow scientists to identify and change traits in a plant to achieve new traits or combinations of traits. Some of these changes are not always achievable with traditional breeding methods. In some cases changes could be made through gene editing that would require multiple rounds of breeding and take many years, particularly for perennial plants that have long breeding cycles, such as tree crops. Introducing a gene editing step would dramatically reduce the time to breed a new variety. The new plant would then enter the same commercial testing process as other varieties, including grower trials, consumer taste trials and storage trials.

What are the benefits of gene editing?

Gene editing may allow us to develop new varieties of crops much faster than traditional breeding and with new traits that have proved difficult to target through traditional breeding. Using gene editing could be particularly important in providing food security to address fast-changing challenges, such as increasingly volatile weather patterns because of changes in the climate.

What are the risks associated with gene editing?

There are risks with any new technology, and gene editing is no different. This includes off-target effects – ie changes in the DNA sequence beyond the gene targeted. These are easily identified through genome sequencing.

Currently in New Zealand, there are strict guidelines in place on where and how the technology can be used – scientists are only using gene editing in containment facilities and with approvals and oversight from the Environmental Protection Agency.

What are the social/ethical implications of gene editing?

Different people have different views on the use of gene technologies, as they do with all new technologies. The decision to use any new technology is made based on analysis of potential risks versus potential benefits.

With gene editing, some people have ethical concerns about incorporating laboratory-made foods into the food chain or the wider environment. Others have economic concerns about the supply of gene edited plants to growers or the impact on New Zealand’s international brand. In New Zealand, there are also considerations of how use of gene editing fits with Te Ao Māori principles.

These concerns are all being taken into consideration as part of the review of regulations being undertaken by MBIE, as well as by food producers as they make decisions on whether to incorporate new breeding technologies into their production process.

Is gene editing being used in New Zealand?

Gene editing is currently being used as a research tool in New Zealand by several organisations, including Crown Research Institutes and universities, and in many research areas, including medicine, agriculture and conservation.

Examples in the primary sector include AgResearch’s research into gene edited endophytes for livestock feed and Scion’s research into sterile pine trees.

What is Plant & Food Research doing with gene editing?

Plant & Food Research is investigating whether gene editing could be used to develop new cultivars for New Zealand’s horticultural sector, and building the technical skills required to ensure gene editing is a viable option for the horticulture sector should they wish to adopt it.

How is gene editing regulated in NZ and the rest of the world?

Currently in New Zealand, gene editing is regulated as genetic modification under the Hazardous Substances and New Organisms (HSNO) Act. However, the regulation of new breeding technologies, including gene editing, is currently under review by the New Zealand government.

Some other countries around the world have changed their regulations for organisms created through new breeding technologies, primarily based on the traits of the resulting organism rather than the process used to create them. This includes Australia, the USA and Japan.

What gene edited products/foods are already in NZ?

There are currently no gene edited foods grown or in the food supply in New Zealand.

Food Standards Australia New Zealand (FSANZ) is reviewing how the Food Standards Code applies to food derived from new breeding technologies (https://www.foodstandards.govt.nz/consumer/gmfood/new-breeding-techniques-nbts)

There are no genetically modified crops grown in New Zealand, however foods made from genetically modified ingredients have been available in New Zealand since 2000, with ingredients approved by FSANZ for import into Australia and New Zealand on a case-by-case basis (https://www.foodstandards.govt.nz/consumer-information/consumer/current-status-genetically-modified-foods-applications). There are close to 100 food ingredients sourced from genetically modified varieties of more than 10 crop plant species approved for import into New Zealand, but none are currently grown in New Zealand.

What are the potential uses for gene editing crops in NZ?

Gene editing could be applied, in theory, to change or enhance any crop trait, including traits that are difficult to select through traditional breeding.

Plant & Food Research scientists are primarily interested in how gene editing could be used to develop plants adapted to grow in new or more volatile climates, with fewer chemical inputs and/or with additional benefits for consumers, like higher concentrations of healthy compounds.

If the NZ regulations changed today, how long would it take to see a gene edited crop for sale in the supermarket?

It takes approximately 5 to 8 years from the time a gene edited plant can be released from the laboratory to the first commercial-sized harvest. This is the time required to ensure the plant has undergone all the commercial testing required, such as grower trials, consumer trials and storage trials, as well as propagating enough plants for growers to grow at commercial scale.

There are a small number of gene edited varieties approved for commercial production overseas. If New Zealand regulations were to change to allow the importation of gene edited foods, products that come from these varieties could be available in supermarkets within a few months of regulation change.

Bringing a gene-edited variety into New Zealand to grow may also be a possibility when regulations change; in this case, it would take approximately 4 to 6 years before the first commercial-sized harvest. This is the time required to fulfil quarantine requirements, test the variety’s performance in the New Zealand environment, and propagate enough plants for growers to grow at commercial scale.