Q&A with Haven Baker on Simplot’s Innate™ Potatoes

Haven Baker, Vice President of Plant Sciences at J.R. Simplot Company

There’s a new genetically engineered potato in town that doesn’t brown when cut or fried, nor does it make acrylamide. J. R. Simplot Company petitioned the USDA to deregulate their Innate™ potatoes, and the public comment period has just been opened up on that petition. We sent Simplot some questions about their new potatoes and the technology used to make them, and their Vice President of Plant Sciences, Haven Baker, was happy to respond. Here is that interview, and if you have more questions about it feel free to ask more, as we have asked Haven to stick around for the discussion.

1. Can you tell us about the new Innate potato traits? How was it decided that these traits would be important to work on?

Absolutely. Simplot is both a pioneering potato processor and food company. With over 60 years in the potato business, we are aware of a number of significant areas where biotechnology can benefit many of the entities that make up the potato food chain. The trick is always matching what is scientifically feasible with what makes business sense. We think that seed growers, farmers, processors and consumers can all benefit from reduced black spot bruise, low asparagine, and slow degradation of starch to sugars during storage.

We know that potatoes’ susceptibility to black spot from impact and pressure during harvest and storage results in significant product losses. Innate™ potatoes’ reduced black spot from bruising will therefore result in a larger usable yield, making potato farming more profitable. Reduced sugars – under certain conditions – provide consistent golden color, providing ideal taste and texture qualities. Reduced levels of asparagine decrease the potential formation of acrylamide, a chemical compound that occurs when potatoes, wheat, coffee, and other foods are cooked at high temperatures. In California, Innate™ potatoes provide a potential means for potato processors to address the acrylamide issues under Proposition 65.

2. It seems that “Innate” is more than just the traits, but is a technology for introducing many traits into potatoes. Can you tell us how this works? Is it intragenic/cisgenic? Why did you choose the name “Innate”?

We thought “Innate” technology was an appropriate term because of the inherent nature of the potato DNA transferring to the potato plant. Simplot’s Innate™ technologies allow researchers to isolate genetic elements from any plant genome, rearrange them, or link them together in desired permutations, and introduce them back into the genome. Inserting an extra copy of a gene into the potato activates a self-defense mechanism known as RNA interference, which silences the genes related to expression of black spot bruise, asparagine, and reducing sugars in tubers.

The inserted genes come from cultivated potatoes or wild potatoes (a group of related plant species that are sexually-compatible with potatoes). We incorporate no foreign genes, no antibiotic resistance markers, and no vector backbone sequences, into the plant genome. We used a vector called pSIM1278, which incorporates two silencing “cassettes” into the potato. Expression of the first cassette lowers transcript levels for the Asn1 (asparagine synthetase-1) and Ppo5 (polyphenol oxidase-5) genes and, consequently, limits the formation of the acrylamide precursor asparagine, and the formation of impact-induced black spot bruise that occurs when the enzyme polyphenol oxidase oxidizes phenols to produce dark pigments. The presence of black spot bruise results in lower quality and subsequent production losses during processing into fries or chips.

A reduction in the formation of reducing sugars is accomplished by the down-regulated transcript levels for the PhL (phosphorylase-L) and R1 (starch associated) genes resulting from expression of the second cassette. These traits function by slowing the conversion of starch to reducing sugars (glucose and fructose). Benefits include improved quality, especially relating to color control, and thus contributing to the desired golden brown colors required by most french fry or chip customers. Also, the reducing sugars react with amino acids, such as asparagine, to produce Maillard products including acrylamide. So by reducing the levels of these sugars in stored potatoes, we can significantly reduce the levels of toxic acrylamide in the food.

Acrylamide is formed when Asparagine is heated to high temperatures (like when frying) in the presence of some sugars. Less Asparagine and sugars means less Acrylamide.

3. How many and which varieties have been transformed with the new traits, and was each transformation done separately?

We transformed five different varieties including three popular varieties – Ranger Russet, Russet Burbank, and Atlantic – and two proprietary chipping varieties. These varieties each involved transformation for two traits (the genes related to expression of black spot bruise & asparagine, and the genes related to reducing sugars in tubers) for a total of ten events, which were done separately.

4. Can Innate potatoes be baked, fried, or cooked like regular potatoes? Do they look of taste different after cooking compared to regular potatoes?

Yes. In extensive field tests and subsequent tasting research, Innate™ potatoes were found to look, taste and have a similar texture as their conventionally grown commercial counterparts and can be cooked exactly the same. However, due to the non-browning trait, they no longer need to be soaked after cutting to prevent browning (for those who used to do that).

5. How long do the non-browning potatoes last after being cut compared to normal potatoes? Would Innate Potatoes help to decrease food waste?

Innate™ and conventional potatoes 10 hours after being sliced.

Innate™ potatoes will not turn brown after being cut for many days until they dry out and degrade naturally, while normal potatoes often begin to turn brown within ten minutes. Obvious signs of potato degradation due to blight, rot or virus will still be apparent in Innate™ potatoes in advanced stages and these will be identified during normal quality control at the grower or processor level since potatoes are typically stored after harvesting. At early stages of growth, most conventional potato varieties do not express the polyphenol oxidase (PPO) enzyme that creates browning when cut or damaged so Innate™ would be no different.

(Editor’s Note: this is the same gene and mechanism that was changed to make the non-browning Arctic Apples.)

In terms of food waste, the blackening that occurs after potatoes are bruised affects the quality and recovery in processing French fries and chips – in bad years this can be more than 5% of all loads, according to the industry. The affected potatoes must be trimmed or face rejection before processing, resulting in quality challenges or economic loss. In fact, some processors reject loads with reducing sugar content above 2%, which we understand can be up to 20% of potatoes produced. However, Innate™ potatoes exhibit significantly less black spot bruising and lower reducing sugar content, which could save growers and processors tens of millions of dollars.

6. How many potatoes are lost during and after harvest due to bruising and black spot?

The answer to this question is more complicated than it seems. Weather, soil temperature, storage conditions and different potato varieties can all affect black spot bruise. It can vary significantly from year to year. That said, in terms of food waste, processors and growers tell us that low black spot bruise will result in savings of up to 5% in rejected loads, reducing post-harvest waste significantly.

7. What sorts of efforts have been made to achieve these traits with conventional breeding? Are there any barriers to developing these traits through breeding?

Traditional plant breeding has undergone efforts to reduce acrylamide and eliminate plant viruses and pests, however the progress has been slow and commercially ready solutions are many years away. Today’s traditional breeding techniques simply result in random genomic rearrangements and trait segregation, and do not allow for the simultaneous addition of multiple desired traits.

There currently are no varieties available that produce tubers with low acrylamide potential, reduced black spot bruise and reduced sugars, while displaying all other traits important to the food industry. Therefore, instead of attempting to develop new varieties, the J. R. Simplot Company improved the quality of five existing potato varieties by transforming them with Innate™ technology.

Transformed Innate™ potatoes in growth medium

Because our Innate™ technologies effectively accelerate the process of conventional crossing, it allows desired changes in traditional varieties to occur much faster than is currently possible, while maintaining the desired characteristics of the original parent plant. For potatoes, InnateTM technologies are particularly attractive because potatoes are notorious for having a high degree of heterozygosity, suffering from inbreeding depression, and limited predominantly to clonal propagation. These inherent factors significantly hinder and prevent us from commercially introducing quality, sought-after traits into this valuable crop.

(Editor’s note: see this video to see how potatoes are bred.)

8. What is the current regulatory status of the Innate Potatoes in the US and elsewhere?

Simplot initiated its USDA regulatory approval in January 2013, and the public comment is now open and will be open until July 2. We hope that approval will come in the following year. In addition, we have initiated the FDA voluntary safety review process and should receive approval as early as this fall. We are currently pursuing regulatory approval in foreign export markets in Canada, Mexico, South Korea and Japan.

9. Will Innate potatoes only be sold to commercial growers, or will they also be available for home gardeners to grow? Will we see Innate potatoes in the supermarket, or are these destined only for processors?

When approved, Innate™ potatoes will initially be available to commercial growers due to the limited availability of mini-tubers used as seeds. We are investigating the opportunity to introduce these potatoes into the supermarket via the fresh market in the future. In the near term, they most likely will not be available for home gardeners.

10. What types of safety evaluation have been conducted for Innate potatoes? How do we know what effect they will have on the environment or on human health? How much of a concern is cross-pollination?

Potatoes are grown from seed potatoes, which are clones of their parents. No pollination involved!

The USDA safety review process is extensive and involves an environmental assessment with results from widespread field trials. These field trials demonstrate that Innate™ potatoes were found to pose no health or environmental risks, create no harm to other species, and grow just like conventional potatoes without the need for special pesticides or fertilizers. There is virtually no risk of cross-pollination since commercial potatoes are grown from tubers, not seed. In addition, many commercial potatoes are either sterile or not sexually compatible with wild potatoes. Wild potatoes are rare and flowers are not frequented by honeybees due to a lack of nectar.

The FDA’s parallel review of Innate™ potatoes, which is also underway, will ensure that they are safe for consumption. Although the FDA submission is voluntary, we consider the FDA review to be an important endorsement of food safety. Simplot’s extensive testing shows these potatoes have the same nutrients, taste, and appearance as conventional potato varieties, which have been proven safe over many years.

In addition, we do extensive internal reviews on the safety of the junction sequences of our Innate™ lines, along with an assessment of potential open reading frames and allergens. For example, the plasmid pSIM1278 was inserted with all expression cassettes intact. An analysis of the insert and junction regions shows no new proteins or allergens that would change the safety of the Innate™ lines compared with the parent varieties. Addition evidence that normal potato characteristics regarding taste and plant growth were not changed was provided in agronomy and composition studies provided to the USDA and FDA.

11. What work has been done on assessing consumer attitudes to these potatoes? Are the details of the acceptance study available for people to examine, or will it be published?

There have been several consumer studies conducted over the past few years. The International Food Information Council (IFIC) has done some research on consumer attitudes to biotechnology foods in general. According to IFIC, 69% of consumers are either likely or somewhat likely to accept biotechnology vegetables, including potatoes if they are tastier or fresher.

In addition, Simplot has commissioned its own proprietary research available on its brochures and website that shows that consumer approval of Innate™ (93%) is similar to traditional plant breeding (94%).

12. It seems that the reduced asparagine trait (and perhaps even the non-browning trait) could be important to consumers. How will they be able to find out about these differences when it comes to purchasing the eventual products, whether as whole potatoes, chips, fries, etc.?

When approved, Innate™ potatoes containing the lower acrylamide will be available in a limited basis in 2014. For 2015 onward, Simplot will increase the supply of Innate™ seed to meet the expected market demand. As appropriate, Simplot will work with chip, fresh and fry processors to communicate the benefits.

13. What do farmers think about them?

Several farmers have been involved in field trials and many more have attended grower-briefing days to see the results. They have told us that they are very excited at the results, in which Innate™ potatoes have the same taste and growth characteristics as their commercially grown counterparts and contain marketable traits for lower asparagine, lower black spot bruise and lower reducing sugars.

One sizeable grower who has seen our field trials, Duane Grant, recently wrote an editorial about them in Truth About Trade & Technology.

14. What other traits are being developed by Simplot that we might see in the future?

This technology shows great promise for future crop enhancements. Simplot Plant Sciences plans to add benefits to current Innate™ potato lines, different potato varieties and even other crops. Our second generation of biotech potatoes will store better and reduce acrylamide by up to a 90%. We have an active research program and are working on Potato Virus Y, improved late blight resistance, and other consumer health traits like increased vitamins or nutrients. Through the endless possibilities of Innate™ technology, we aspire to create better fruits and vegetables, farming and human health.

–Haven Baker

Feel free to as additional questions, and if you want to comment on the petition for deregulation you can do so here. Thank you Haven for taking the time to answer these questions for our readers, and to Julie Sally for helping to arrange the interview.

Update May 9, 2013: Haven Baker met Frank yesterday! Here is the photo.

Haven Baker

Follow Karl Haro von Mogel:
Karl earned his Ph.D. in Plant Breeding and Plant Genetics at UW-Madison, with a minor in Life Science Communication. His dissertation was on both the genetics of sweet corn and plant genetics outreach. He recently moved back to his home state of California. His favorite produce might just be squash.