Described herein are downy mildew resistant genes in sunflower and downy mildew resistance sunflower plants. Specifically, the present invention relates to sunflower plants being resistant to the plant pathogen downy mildew, wherein the plant comprises a downy mildew resistance conferring gene encoding a protein including the amino acid sequence as shown in SEQ ID No. 2 or SEQ ID No. 4 and wherein the expression of the resistance conferring gene is reduced as compared to the expression of said resistance conferring gene in a sunflower plant not being resistant to the plant pathogen downy mildew or the enzymatic activity of said protein is reduced as compared to the enzymatic activity of said protein in a sunflower plant not being resistant to the plant pathogen downy mildew.