Molecular mechanism of the parasitic interaction between Orobanche cumana wallr. and sunflowers

ABSTRACT Orobanche cumana Wallr. is the most serious parasitic weed that threatens sunflower production in China, it infects sunflower roots and causes severe yield and economic losses. This study determined the effects of O. cumana infection on sunflower growth, physiological, biochemical, photosynthesis indexes and used RNA-Seq to investigate the potential regulatory factors involved in the parasitic interaction. Results showed that O. cumana infestation significantly inhibited sunflower height, fresh weight, chlorophyl contents, photosynthetic and the MDA content, SOD and POD activities were increased in different degrees, which might be related to sunflower resistance to O. cumana infestation. Additionally, six parasite-related genes were selected, which markedly enriched in plant hormone signal transduction, photorespiration and phenylpropanoid metabolism pathway. Among these genes, HsP90A, MYC2 and HAO were discovered for the first time in sunflowers and O. cumana parasitic interaction. Undoubtedly, the results lay a foundation for revealing the parasitic interactions molecular mechanism of O. cumana and sunflowers.