Rapid pollen rupture and release of pollen cytoplasmic granules upon hydration of allergenic grass and weed species commonly found in subtropical regions

Abstract

© 2019, Springer Nature B.V. Airborne pollen is an important and potent source of allergens. Allergenic protein components located in the cytoplasm of pollen, so-called pollen cytoplasmic granules, are released upon contact with moisture, thereby inducing allergic symptoms. However, few studies have compared factors affecting pollen rupture and protein release from allergenic pollen. This study investigated the dynamics of pollen rupture and protein release upon hydration using common allergenic grass and weed species in subtropical regions. The three factors examined were incubation time, incubating solution, and pollen age after shedding. We found that pollen rupture and protein release occurred rapidly upon contact with solutions. The highest amount of protein was released within 15 min after incubation. As expected, pollen rupture increased as incubation time increased. Fresh pollen had higher rupture percentage and released a higher amount of protein than aged pollen. Rainwater caused more rupture and triggered more protein release than other tested solutions. The dynamics of rupture and the amount of released protein were drastically different among species. In conclusion, incubation time, incubating solution, and age of pollen significantly affected the amount of pollen rupture and protein release from allergenic pollen. This information provided better understanding of factors involving the release of allergenic protein from pollen in relation to its internal and external conditions, which could affect its allergenicity.