Host-pathogen interaction in sugarcane and red rot pathogen: exploring expression of phytoalexin biosynthesis pathway genes

Sugarcane crop, the major source of sugar is a high value commercial crop. The importance of the crop is growing as it has the potential to boost the green fuel production and various other eco-friendly products. The fungal disease, red rot (Colletotrichum falcatum) is a dreadful one and studying the dynamics of host-pathogen interaction is essential to develop disease resistant varieties. Earlier, the role of 3-deoxyanthocyanidin phytoalexins in red rot resistance was established. Further studies were made to assess antifungal activities of these compounds against C. falcatum through in vitro assays. Since phenyl propanoid biosynthesis pathway is the major secondary metabolite producing pathway which leads to production of flavonoids, isoflavonoids and lignin, studies were made to explore expression dynamics in major gene transcripts involved in anthocyanidin pathway by qRT-PCR. Our studies showed antifungal nature of the sugarcane phytoalexins 3-deoxy anthocyanidin compounds, apigeninidin and luteolinidin along with differential expression of transcripts involved in the phytoalexin biosynthesis pathway during compatible and incompatible interactions. © 2021, Indian Phytopathological Society.