Location: Sugarbeet and Potato Research
2022 Annual Report
Objectives
Objective 1: Delineate and integrate the molecular processes that control cytokinin content and their biological activities during tuber dormancy progression and wound-healing.
Sub-Objective 1-1: Determine changes in tuber meristem cytokinin content and expression of genes encoding cytokinin biosynthetic enzymes during dormancy progression.
Sub-Objective 1-2: Determine changes in the expression of cytokinin-responsive histidine kinase genes and the acquisition of cytokinin sensitivity during tuber dormancy progression.
Sub-Objective 1.3: Determine changes in cytokinin content and the expression of genes encoding key cytokinin metabolic enzymes in tuber tissues following mechanical wounding.
Objective 2: Quantify nitric oxide release during potato storage and handling and determine nitric oxide involvement in tuber dormancy progression and wound-healing.
Sub-Objective 2.1: Determine the release and role of NO in potato tuber dormancy exit.
Sub-Objective 2.2: Determine the release and role of NO in the potato tuber wound-healing response.
Objective 3: Determine the effects of postharvest storage on process quality and nutritional composition of advanced breeding lines in collaboration with public potato breeding programs (non-hypothesis driven).
Sub-objective 3.1: Determine storage and processing characteristics of advanced breeding lines.
Sub-objective 3.2: Screen advanced potato breeding lines for cold storage potential.
Objective 4: Determine the total antioxidant and ascorbic acid (vitamin C) contents of advanced breeding clones at harvest and during temperature-controlled storage (non-hypothesis driven).
Objective 5: Identify and characterize the physiological and molecular mechanisms that regulate and maintain meristem dormancy in potato tubers and evaluate strategies to inhibit tuber sprouting during storage.
Approach
Worldwide, the potato ranks fourth among the major food crops. Global potato production exceeds 364 million metric tons (FAOSTAT, March, 2013) and U.S. production exceeds 437 million cwt (USDA-NASS, January, 2013) of which over 400 million cwt worth an estimated $2.01 billion are harvested in the fall. Over 70% of the fall potato crop is placed into storage for year-round use. Unlike other major food crops, potatoes are stored in a fully hydrated and highly perishable form. Postharvest losses routinely approach 10% of the stored crop and occur through both physiological and disease-related processes. Two of the most important physiological processes affecting potato storage and market quality are dormancy/sprouting and wound-healing. Despite the severity of these losses, management strategies and technologies employed to combat these problems were empirically derived, are several decades old and do not effectively meet today’s consumer or industry demands to control damage, minimize physiological deteriorations, and reduce disease problems. Further improvements in postharvest storage technologies are hindered by ignorance of the biological mechanisms underlying these physiological processes. The goals of this project are to identify critical molecular, biochemical and physiological mechanisms controlling tuber dormancy/sprout growth and wound-healing and, ultimately, to genetically, chemically, or physically manipulate these rate-limiting processes to develop improved methods to maintain potato nutritional and processing quality during storage. Specific goals are: 1) Identify the cognate processes that control cytokinin content and activity during postharvest storage/wound-healing, and 2) Determine the involvement of nitric oxide in tuber dormancy progression and wound-healing.
Progress Report
This is the final report for this project (#3060-21430-008-00D) which terminated in April 2022. This project started in April 2020 to bridge and merge two potato research project plans (#3060-21430-007-00D; #3060-43440-013-00D) while the new project plan for the next five years was undergoing review by the Office of Scientific Quality Review (OSQR).
The bridge project (#3060-21430-008-00D) included five objectives: Objectives 1, 2 and 5 were transferred from project #3060-21430-007-00D “Improving Potato Nutritional and Market Quality by Identifying and Manipulating Physiological and Molecular Processes Controlling Tuber Wound-Healing and Sprout Growth”; both investigators responsible from this project retired during the lifecycle of the project (refer to the Fiscal Year 20 final report) and one of these positions is still vacant. Objectives 3 and 4 were transferred from project #3060-43440-013-00D “Improved Potato Market Quality Through Germplasm Processing Evaluations and Optimized Storage Technologies”.
During the lifecycle of this bridge project plan (#3060-21430-008-00D) limited progress was made towards Objective 1, 2 and 5 due to remaining critical vacancies and redirection of research on tuber dormancy and wound healing in the new project plan that went under Office of Scientific Quality Review in Fiscal Year 21-22. However, in Fiscal Year 22, significant progress was made for establishing the new potato physiology research program, and planning and initiating experiments towards the relevant objective (i.e., Objective 1) of the new project plan while it was undergoing Office of Scientific Quality Review. See the report for the replacement project, #3060-21430-009-00D, “Improving Potato Postharvest Quality by Identifying and Manipulating Molecular Processes Regulating Tuber Dormancy and Wound-Healing” for additional information. For Objective 1 of the new project plan (#3060-21430-009-00D), several potato cultivars were planted in the field and greenhouse to obtain tubers in the fall for postharvest physiology research partnering with collaborators and growers. Several collaborations with university researchers and stakeholders were established, and grant proposals were submitted to conduct research to complement the objectives of parent project that was under review. Two of these collaborative research projects have received awards from the Agriculture Research Service - State Partnership Potato Research Program in FY22 complementing the new project Objective 1.
To complement the new project plan (#3060-21430-009-00D) Objective 1.A-B, experiments were conducted in collaboration with the University of Idaho cooperators to determine effects of promising essential oil (EO) treatments for tuber sprout suppression. Three EOs (organic spearmint, organic oregano, and organic sweet orange) were selected for an efficacy trial based upon potential direct utilization as sprout suppressors in the potato industry. The trial included two levels of sprouted tubers (peeping and surpassed dormancy break) of Russet Burbank cultivar. EOs were applied to tubers in application chambers, then sprout growth was evaluated 6d and 30d after the treatments. While the three EOs showed the ability to physically damage sprouts and suppress sprout growth for a short period of time, oregano EO was very effective at causing peeping eyes to be damaged and blacken when evaluated 6d after application and showed promise as a “rescue treatment” to potatoes that had broken dormancy. A parallel experiment, where the three EOs were applied to Russet Burbank mini-tubers prior to eye-movement stage, suggests that spearmint EO delays the sprout growth ~4 weeks compared to the untreated controls at 8C storage. Further experiments are underway to confirm the efficacy of these EOs and evaluate their potential utilization as sprout suppressor in the potato industry.
To complement the new project plan (#3060-21430-009-00D) Objective 1.C, experiments were initiated in collaboration with the North Dakota State University cooperators to investigate the efficacy of elicitor treatments to improve wound-healing responses in cut and bruised potato tubers. A model wounding system was used for extracting discs from mini and large tubers of potato cultivars (Russet Burbank, Chieftan, Dakota Rose, Dakota Ruby, Red Norland, and Red LaSoda) followed by treatments with natural elicitors (COS; NutriCran) or controls (dimethylsulfoxide buffer; Fluridone). Suberization ratings, total soluble phenolic content and antioxidant activity were determined in wounded and treated disc tissues 0-9 days after wounding. Improved wound-healing response with significantly higher suberization ratings were observed in tubers of all potato cultivars after NutriCran and COS elicitor treatments. Experiments are underway to determine the role of biochemical pathway regulations in wound healing processes using the wounded and elicitor treated potato disc tissues.
During the lifecycle of this bridge project plan (#3060-21430-008-00D), significant progress was made in the non-hypothesis driven Objectives 3 and 4. Cooperative research has been fostered among university breeding programs, USDA-ARS potato breeding programs, and potato industry grower and processing stakeholders. Annual processing quality evaluations were performed throughout storage among advanced breeding clones and new potato varieties representing public breeding programs (Objective 3.1). Potato clones possessing improved processing quality and cold storage potential were identified (Objective 3.2). Processing quality of fry and chip clones was assessed among Potatoes USA sponsored National Chip and Fry field and processing trials (Objective 3.1). Tuber antioxidant (vitamin C) concentrations and anti-quality compounds including glycoalkaloids were quantified among new potato clones at harvest and throughout storage (Objective 4). This cooperative evaluation process has streamlined the introduction of new potato cultivars with superior processing characteristics in storage, and has been considered gold-standard by the potato industry and stakeholders in the United States.
Objectives 3 and 4 of this bridge project plan (#3060-21430-008-00D) are covered under Objective 2 of the replacement project plan (#3060-21420-009-00D); see the report for the replacement project for additional information.
Accomplishments
1. Utility of essential oils to control tuber sprout growth. Potato tuber dormancy and sprout growth are major challenges during postharvest storage. Commonly used sprout inhibitors have come under regulatory scrutiny, prompting the continued search for alternative methods to control sprout growth. ARS scientists in Fargo, North Dakota, in cooperation with University of Idaho scientists, determined that organic spearmint, oregano, and sweet orange essential oils (EOs) can suppress sprout growth. Particularly, oregano EO showed promise as a “rescue treatment” to potatoes that had broken dormancy, and spearmint EO delayed the sprout growth ~4 weeks when applied to tubers prior to eye-movement stage. Additional research is underway focusing on the optimization of EOs for potential utilization as sprout suppressors in the potato industry, which will be critical for the development of benign methods to control sprouting in bulk stored potatoes.
2. Natural elicitors enhance wound healing responses of potatoes. Wounding and bruising of potato tubers occur during harvest, handling, and transportation, which results in major financial losses for potato growers. Acceleration of wound-healing of bruised tubers is essential for reducing postharvest crop losses and ensuring better tuber quality. ARS scientists in Fargo, North Dakota, along with North Dakota, State University scientists, determined that natural elicitor treatments improve wound-healing response of tubers by enhanced suberization, and biosynthesis of protective compounds and modulation of stress-induced metabolic pathways. These results provide new insight into the regulation of wound periderm formation, which is critical in the development of new methods to hasten wound-healing and thereby reduce rot and nutritional/quality deterioration for growers, processors, and consumers.
3. Potato post-harvest quality evaluations and release of new potato cultivars. Acceptable processing quality after storage is an essential attribute of a successful potato variety. The standardized evaluation procedures developed and used by scientists in East Grand Forks, Minnesota, have been an important component of the overall process evaluation and release of new cultivars by federal and state cooperators nationwide. In the past year, in support of federal and non-federal public breeding/screening programs, 161 advanced breeding lines were analyzed for storage/processing quality at multiple storage temperatures and durations. Data from these analyses will contribute to the release of new potato varieties. These improved varieties offer significant benefits to both producers and processors and should be widely adopted by the potato industry.
4. Potato cultivars with reduced acrylamide concentration identified. Acrylamide is an unwanted and potentially toxic by-product produced when carbohydrate-rich foods are processed at high temperatures. Among entries in National Fry Processing Trials, several clones exhibiting excellent processing characteristics and very low acrylamide levels were identified by ARS scientists in East Grand Forks, Minnesota. These clones will be evaluated in more detailed trials and may be candidates to replace currently used varieties in the commercial production of processed potato products. Eventual adoption of these clones and consequent reduction in the acrylamide concentration of potato products will benefit both producers and consumers.
Review Publications
Hussain, B., Akpinar, B.A., Alaux, M., Algharib, A.M., Sehgal, D., Ali, Z., Aradottir, G.I., Batley, J., Bellec, A., Bentley, A.R., Cagirici, H.B., Cattivelli, L., Choulet, F., Cockram, J., Desiderio, F., Devaux, P., Dogramaci, M., Dorado, G., Dreisigacker, S., Edwards, D., El-Hassouni, K., Eversole, K., Fahima, T., Figueroa, M., Galvez, S., Gill, K.S., Govta, L., Gul, A., Hensel, G., Hernandez, P., Herrera, L.C., Ibrahim, A., Kilian, B., Korzun, V., Krugman, T., Li, Y., Liu, S., Mahmoud, A.F., Morgounov, A., Muslu, T., Naseer, F., Ordon, F., Paux, E., Perovic, D., Reddy, G.V., Reif, J.C., Reynolds, M., Roychowdhury, R., Rudd, J., Sen, T.Z., Sukumaran, S., Ozdemir, B.S., Tiwari, V., Ullah, N., Unver, T., Yazar, S., Appels, R., Budak, H. 2022. Capturing wheat phenotypes at the genome level. Frontiers in Plant Science. 13. Article 851079. https://doi.org/10.3389/fpls.2022.851079.
Chintha, P., Sarkar, D., Pecota, K., Dogramaci, M., Shetty, K. 2021. Improving phenolic bioactive-linked functional qualities of sweet potatoes using beneficial lactic acid bacteria-based biotransformation strategy. Horticulturae. 7(10). Article e367. https://doi.org/10.3390/horticulturae7100367.
Wang, H., Dogramaci, M., Anderson, J.V., Horvath, D.P., Chao, W.S. 2021. Transcript profiles differentiate cold acclimation-induced processes in a summer and winter biotype of camelina. Plant Molecular Biology Reporter. https://doi.org/10.1007/s11105-021-01324-4.
Finger, F.L., Eide, J.D., Dogramaci, M., Fugate, K.K. 2021. Methyl jasmonate effects on sugarbeet root responses to postharvest dehydration. PeerJ. 9. Article e11623. https://doi.org/10.7717/peerj.11623.
Ramakrishna, R., Sarkar, D., Dogramaci, M., Shetty, K. 2021. Kefir-culture mediated fermentation to improve phenolic-linked antioxidant, anti-hyperglycemic and human gut health benefits in sprouted food barley. Journal of Applied Microbiology. 1(2):377-407. https://doi.org/10.3390/applmicrobiol1020026.
