Unveiling protein elicitor MoHrip2: A potent biocontrol agent extracted from Magnaporthe oryzae safeguards Australian tobacco (Nicotiana benthamiana) against tobacco aphid (Myzus nicotianae)

Abstract

The tobacco aphid (Myzus nicotianae) poses a significant threat to global Australian tobacco (Nicotiana benthamiana) output by inflicting damage through leaf twisting and feeding during its early growth stages. To explore potential herbivore resistance in N. benthamiana, this study investigates the effects of the elicitor protein MoHrip2, derived from Magnaporthe oryzae, on the immature growth, survival, and lifespan of M. nicotianae. Compared to the control group, MoHrip2 treatments at three concentrations (85.24, 51.14, 25.57 μg/mL) reduced M. nicotianae population after 7 days, 14 days, and 21 days. All concentrations significantly reduced aphid colonization rate, except for the lowest elicitor concertation (25.57 μg/mL at 7D). Likewise compared to the control group, the highest concentration of MoHrip2 i.e. 85.24 μg/mL, resulted in a decrease in the growth rates of M. nicotianae (second and third-generation). M. nicotianae colonized control plants quicker than MoHrip2-treated N. benthamiana plants in a host selection test. MoHrip2 (85.24, 51.14, 25.57 μg/mL) concentrations extended M. nicotianae nymphal development. The trichomes and wax on MoHrip2-treated leaves made M. nicotianae environment hostile. M. nicotianae reproduction and colonization were reduced by MoHrip2's leaf surface changes. Electrical penetration graphs (EPGs) against M. nicotianae assessed adult reproductive efficiency and pest-pathogen interaction. MoHrip2-treated N. benthamiana seedlings exhibited increased amounts of expression of genes involved in jasmonic acid (JA), salicylic acid (SA) pathways indicating the activation of systemic defense against M. nicotianae. This study reveals a direct correlation between temperature variations and climatic shifts in N. benthamiana plants, highlighting the potential of MoHrip2 in revolutionizing agroecosystems through enhanced pest management and biocontrol strategies. In conclusion, the present study sheds new light on the potential of MoHrip2, derived from M. oryzae, as an effective biocontrol technique against M. nicotianae, infesting N. benthamiana. These findings provide valuable insights into developing innovative and sustainable solutions for pest management in agricultural practices, considering the evidence presented against M. nicotianae, it can be concluded that implementing integrated pest management and utilizing MoHrip2 for bio control in the agroecosystem is an appropriate approach.