Transgenic ryegrasses (Lolium spp.) with down-regulation of main pollen allergens

Ryegrass pollen (Lolium species) is a widespread source of air-borne allergens and is a major cause of hayfever and seasonal allergic asthma, which affect approximately 25% of the population in cool temperate climates. The main allergens of ryegrass pollen are the proteins Lol p 1 and Lol p 2. These proteins belong to two major classes of grass pollen allergens to which over 90% of pollen-allergic patients are sensitive. The functional role in planta of these pollen allergen proteins remains largely unknown. Here we describe the generation and analysis of transgenic plants with reduced levels of the main ryegrass pollen allergens, Lol p 1 and Lol p 2 in the most important worldwide cultivated ryegrass species, L. perenne and L. multiflorum. These transgenic plants will allow the study of the functional role in planta of these pollen proteins and the determination of potential for development of hypo-allergenic ryegrass cultivars.