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Mikania micrantha Kunth is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production. Although Puccinia spegazzinii can effectively inhibit the growth of M. micrantha and is used as a biological control strain in many countries, the mechanism of inhibiting the growth of M. micrantha is not clear. Here, we used a combination of phenotypic, enzyme activity, transcriptomic, and metabolomic approaches to study the response of M. micrantha after infection by P. spegazzinii. In the early stages of rust infection, jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile), and salicylic acid (SA) levels in infected leaves were significantly lower than those in uninfected leaves. In teliospore initial and developed stages of P. spegazzinii, JA and JA-Ile levels substantially increased by more than 6 times, which resulted in a significant decrease in the accumulation of defense hormone SA in infected leaves of M. micrantha. The contents of plant growth-promoting hormones were significantly reduced in the infected plants as a result of substantial downregulation of the expression of key genes related to hormone biosynthesis. Furthermore, rust infection led to high levels of reactive oxygen species in chloroplasts and the destruction of chlorophyll structure, which also led to decreased photosynthetic gene expression, net photosynthetic rate, activity of Rubisco, and levels of important organic acids in the Calvin cycle. We hypothesized that after P. spegazzinii infection, JA or JA-Ile accumulation not only inhibited SA levels to promote rust infection and development, but also impeded the rapid growth of M. micrantha by affecting plant growth hormones, carbon, and nitrogen metabolic pathways.

• Bactrocera minax is an economically important pest of citrus. • Protein supplements showed a positive effect on the survival and reproduction of adults B. minax. • These findings provide deeper understanding of the biological characteristics of B. minax that could be utilized for an effective control., Bactrocera minax (Enderlein) (Diptera: Tephritidae) is a major citrus pest in China, whose artificial rearing technology of the adult is not well documented to date. In this study, we tried to determine if supplementing proteins to the adult diet could result in the enhancement of some fitness parameters of B. minax. Four feeds with varying protein source were provided as F0 (water), F1 (sucrose), F2 (sucrose + yeast), and F3 (sucrose + peptone). F0 and F1 being the control, F2 and F3 were protein food types. The results showed that adults fed by F2 and F3 lived longer with 40.1 d and 32.8 d, respectively, had reduced death rates (death peaks were delayed for 5.6 d and 4.1 d, respectively), increased mating frequencies (8.1 and 5.3 per females, 4.7 and 7.3 per males, respectively), and longer mating durations (with 42 d and 34 d). In addition, females recorded an increased adult ovary development, more egg load (with 94.8 and 77.3 brood eggs per ovary) and to greater oviposition rates of 63.2 eggs/female and 19.3 eggs/female. Based on our results, protein supplements enhanced B. minax survival, mating, and fecundity. This study does not only provide basic knowledge to implement artificial rearing of B. minax, but also deepens our understanding on its physiology that could be used to enhance the management of the pest.