Building Improved Food Security

Sunday, October 9, 2022

USask to begin research into new strategies for crop protection.

by Colleen Halpenny

"As markets continue to be volatile, and with ever-changing growing conditions – and consumers looking to have a stable food supply – we must find new ways to bolster plants to thrive.

"What can have the largest potential positive impact?"

This is what Dr. Karen Tanino says that she and colleague, Dr. Tawhidur Rahman, hope to find out through new funding for their research on crop protection.

Tanino is a PhD and professor at the University of Saskatchewan (USask), College of Agriculture and Bioresources, and Rahman is a professional research associate at USask.

The team is expanding on Tanino's previous work examining the cuticular layer of plants in new strategies of crop protection.

Their research project recently received $435,531 in funding from the Government of Saskatchewan's Agriculture Development Fund, supported by the Canadian Agricultural Partnership (CAP).

The CAP is a five-year, $3-billion investment by federal, provincial, and territorial governments to strengthen and grow Canada's agriculture, agri-food and agri-products sectors.

This includes a $2-billion commitment, cost-shared 60 per cent federally and 40 per cent provincially/territorially, with a $388-million investment in strategic initiatives for Saskatchewan agriculture.

Tanino's work "aims to determine if specific components of the plant's cuticle layer, such as its wax, can be identified to enable breeders to efficiently select and improve crops with added protection," she notes.

"Historically, we've placed attention on crop tolerance to stressors such as heat, cold, frost, drought and insects, to name a few. However, energetically it will be most beneficial to the plant to avoid the stress than to have to endure it."

Through evolution, "the progress of plants adapting to land, and new climates, the plant had many avoidance strategies.

"We're focusing our efforts on the cuticular layer, the skin of the plant, and what avoidance strategies can be better utilized to increase crop protection."

The cuticular layer of the plant is its first line of defence, according to Rahman.

"It's much like our own skin, covering the whole plant. It helps to prevent water loss. But what else may this layer be used for to assist in resisting negative effects?" he asks.

Their research will focus on those key common features of the plant and its structures, which protect against multiple stresses. "As Prairie producers well-know, the main stressors are not the same year after year. So, we must work to find the best solutions for them all," says Tanino.

"Previous trials with onions and focusing on the underlying cell walls of the cuticular layer have also shown positive results reducing dehydration stress and disease entrance into the cell."

A temporary protective layer could potentially be developed to help plants avoid heat and frost stress while the world continues to grapple with climate change. Frost conditions are also becoming more prevalent, as earlier springs increase the risk of frost affecting newly-planted crops and fall frosts can threaten the crop before harvest.

"We also found that increased resistance to blocking ice entrance was due to the type and amount of wax present on the cuticular layer," Tanino notes.

"These longer chain waxes on the cuticular layer are hydrophobic. So, they naturally do not allow the water to freeze on the plant and cause damage."

The longer chain waxes are a positive influence in crop protection, according to Rahman. "So now we must identify which of the plant factors are crucially involved in long-chain wax production, and how we can integrate them into the structure of canola.

"Previous work was done in a model setting with Arabidopsis, a close relative of canola.

"We've studied to identify the functions of two genetic factors that can significantly impact the composition and the total amount of cuticular wax of the plant. We're working to find ways in which we can manipulate these factors to change the cuticular wax layer to be more readily available as an avoidance tactic for the plant," he says.

Speaking about their previous trials with Arabidopsis, Rahman outlines that they challenged mutant and transgenic plant lines against dehydration and freezing experiments. From this data, they were able to conclude how the trait of cuticular wax can protect the plant from water loss under drought, and from freezing under sub-zero temperature conditions.

The Prairies' major crops provide enough variety across production types that Rahman and Tanino will "study to find the best common cuticular layer structures to provide the widest spread impact for producers," Rahman says.

Tanino also shares that they'll be exploring chemicals that are already registered for use.

"For example: on potatoes as an insect protectant, but now we'll examine their influence in frost and heat avoidance. In working with these chemicals and other natural waxes which could be extracted and physically applied to the plant, we're able to assist in creating a better barrier to stress."

While canola is the golden crop of the Prairies, Tanino has also included potatoes in her study.

"For those in the horticulture sector, there's a common frustration when the first frost hits in the fall. Usually, the next two to three weeks are an additional time of great growing weather.

"If we can assist the plants in withstanding both the spring and fall frost period, the impacts of an extended growing season are only positive.

"Working to find new solutions for producers to offset potential crop losses is important work for our industry, regardless of crop type," Tanino says.

"For example, there was a recent study from Peru where they showed yields could be increased by 20 to 40 per cent with just a singular degree increase in frost protection.

"Imagine the impact that could have on canola and other sensitive crops when it's a seedling and has not fully established its cuticular wax volume and composition."

Rahman expands on the genetics in canola, for example. "Would there already be an important genetic factor present in canola – that it may have inherited throughout evolution – which we should be focused on manipulating to cultivate a better plant? The plant is already making the wax; how do we synthesize it to maximum potential?"

"We're currently using a number of genetic technologies to identify these factors, to not only better understand the plant, but what it needs to thrive," he continues.

Tanino notes that although they're not breeders themselves, the long-term goal of their project is breeder-focused and will examine how to increase production of these long-chain waxes, or adjust their composition, allowing the plant more avoidance strategies.

"If we can tune into these key factors, breeders will then be able to find the best implementations to produce better-adapted cultivars."

These changes will impact the plant not only on a molecular level but with physical attributes.

Not only focusing on the frost component, Tanino and Rahman are also investigating how to exploit heat stress avoidance opportunities.

Tanino says they're also focusing on better utilizing beta-diketones.

"These compounds assist in reflecting excess light from the surface of the leaf, and thereby prevent heat buildup. Another great avoidance rather than tolerance strategy.

"High volumes of beta-diketones are found in straw from wheat and flax – the waste products of a crop, which the Prairies has in abundance.

Working to synthesize these will be a value-added strategy to improve various production industries," she says.

"Remembering that not everyone will face the same crop stressors and that the variables of each year will bring new challenges, we really strive to find overreaching solutions and new strategies to as many producers as possible." BF