The present invention relates to the production of modified influenza viral proteins in plants. More specifically, the present invention relates to producing and increasing influenza virus-like particle (VLP) production in plants, wherein the VLPs comprise the modified influenza viral proteins, such as modified influenza hemagglutinin (HA). The HA protein may comprising an amino acid sequence comprising at least one substitution when compared to a corresponding wildtype amino acid sequence. Further provided are nucleic acid encoding the modified HA protein. Furthermore methods of producing an influenza virus like particle (VLP) and methods of increasing yield of production of an influenza virus like particle (VLP) in a plant, portion of a plant, or a plant cell, are also provided.本發明關於植物中修飾的流感病毒蛋白質的產生。更具體地,本發明關於在植物中產生和增加流感類病毒顆粒(VLP)的產生,其中VLP包括修飾的流感病毒蛋白質,例如修飾的流感血球凝集素(HA)。當與對應的野生型胺基酸序列相比時,HA蛋白質可包括含有至少一個取代的胺基酸序列。進一步提供了編碼修飾的HA蛋白質的核酸。此外,還提供了產生流感類病毒顆粒(VLP)的方法和增加在植物、植物的一部分或植物細胞中流感類病毒顆粒(VLP)的產生的產量的方法。