Proteomic Analysis of Developing Pecan Nuts

Authors: CLERMONT, KRISTEN - Oak Ridge Institute For Science And Education (ORISE); Grimm, Casey; Mattison, Chris

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2019
Publication Date: 8/23/2019
Citation: Clermont, K., Grimm, C.C., Mattison, C.P. 2019. Proteomic Analysis of Developing Pecan Nuts. Meeting Abstract. 2019.

Interpretive Summary: The prevalence of food allergies appears to be increasing and IgE-mediated food-related allergic reactions can be life threatening. Allergies to tree nuts are rarely outgrown, and the risk of accidental exposure is a constant threat for those with pecan nut allergy. Pecan (Carya illinoinensis) species are native to North America and are an important agricultural crop in some part of the United States. Pecan nuts are packed with nutrition and have excellent health benefits. However, pecan nut seed storage proteins commonly act as food allergens. Pecan kernel development requires the coordinated accumulation of numerous different proteins at specific times. Correctly regulated protein accumulation is essential, and defects in this process will likely affect the quality and quantity of a given pecan nut harvest. We have used modern proteomics methods to characterize the timing and sequence of proteins accumulated during the latter stages of pecan nut development. We have identified proteins that accumulate to high levels during the building of a pecan kernel, and have characterized the accumulation of pecan allergens, and numerous proteins involved in lipid and antioxidant metabolism. The information gained will be a valuable tool for pecan nut researchers and use of this information could guide future research studying biotic and abiotic contributions to pecan nut protein content. Studying protein accumulation could identify cultivars and or agricultural methods that reduce or eliminate pecan nut allergens thereby enhancing food safety and benefitting both consumers and growers.

Technical Abstract: The prevalence of food allergies appears to be increasing and IgE-mediated food-related allergic reactions can be life threatening. Allergies to tree nuts are rarely outgrown, and the risk of accidental exposure is a constant threat for those with pecan nut allergy. Pecan (Carya illinoinensis) species are native to North America and are an important agricultural crop in some part of the United States. Pecan nuts are packed with nutrition and have excellent health benefits. However, pecan nut seed storage proteins commonly act as food allergens. Pecan kernel development requires the coordinated accumulation of numerous different proteins at specific times. Correctly regulated protein accumulation is essential, and defects in this process will likely affect the quality and quantity of a given pecan nut harvest. We have used high-throughput proteomics to characterize protein accumulation in developing pecan nuts during the months of August through October. The majority of protein accumulation occurs in mid to late September and continues into October. Approximately 40% of identified proteins were involved in metabolic processes, 23% were unidentified, 13% in transcription and translation, 7% in housekeeping functions, and 6% in cytoskeletal related functions. Smaller percentages of total protein were involved in signaling, ripening, plant protection, and pecan allergen accumulation was characterized. The results of this project are likely to lead to identification of post-translational protein modifications, unique methods to identify cultivars with reduced or missing allergens, and better diagnostic methods for detection of pecan allergens.