Potato Review

www.potatoreview.com POTATO REVIEW MARCH/APRIL 2022 19 HEAT STRESS Rumiana highlighted the increases in the tuber weight and size of the Quantis treated plants. “Quantis increased the weight of the tubers by 5% and increased the size of the tubers by two- fold, compared with the control.” Gene expression Further experiments at University of Nottingham sought to define the gene expression changes underlying biological function and metabolic processes that are associated with Quantis treatment. “We found that Quantis treatment resulted in enriched defence response and significant enrichment of the zeatin biosynthetic pathway in potato plants” she said. That was followed up with hormonal analysis and quantification, which was able to identify that plants treated with Quantis had greater concentrations of abscisic acid and cytokinins, in contrast to gibberellic acid, at seven days post application. “That fits nicely with some of the physiological data that we have observed with Quantis treated plants,” added Rumiana. “Gibberellic acid is known to inhibit tuberization, whilst cytokinins enhance cell expansion and tuber formation. Abscisic acid is associated with decreased photoxidative stress.” “The climate is changing, and our summers are getting hotter,” Andy Cunningham said. “It’s heat stress that is going to have the major impact on how our crops grow. Having a product such as Quantis that has been proven to have a physiological benefit to the plant to allow it to maintain yield through periods of heat stress could become increasingly valuable. “The fact that it has been shown to continue through to increased yields in the experiments further explains and confirms what we have seen in the field with trials and growers’ own experiences,” he said. Quantis trials - Flurocam imagery in action under heat stress, increased photosynthesis, and that was associated with increased functionality of the stomata, measured by stomatal conductance, and decrease in non-photochemical quenching. “We can suggest that these first results suggest that plants that are treated with Quantis were able to use absorbed energy more productively, because we have preferential allocation of energy towards photochemistry – driving photosynthesis rather than heat dissipation. Results from the fluorcam at 7 days post application were pretty consistent in terms of increased efficiency of photosynthesis and reduced non-photochemical quenching.” “Gibberellic acid is known to inhibit tuberization, whilst cytokinins enhance cell expansion and tuber formation.”