Study on RNAi-based herbicide for Mikania micrantha

Abstract

The invasive plant Mikania micrantha Kunth ( M. micrantha ) from South America poses a significant threat to the stability and biodiversity of ecosystems. However, an effective and economical method to control M. micrantha is still lacking. RNA interference (RNAi) has been widely studied and applied in agriculture for trait improvement. Spray-induced gene silencing (SIGS) can produce RNAi silencing effects without introducing heritable modifications to the plant genome and is becoming a novel nontransformation strategy for plant protection. In this study, the genes encoding chlorophyll a/b-binding proteins were selected as targets of RNAi, based on high-throughput sequencing of M. micrantha transcriptome and bioinformatic analyses of sequence specificity. Three types of RNAi molecules, double-stranded RNA, RNAi nanomicrosphere, and short hairpin RNA (shRNA), with their corresponding short interfering RNA sequences were designed and synthesized for SIGS vector construction, from which each RNAi molecule was transcribed and extracted to be sprayed on M. micrantha leaves. Whereas water-treated control leaves remained green, leaves treated with RNAi molecules turned yellow and eventually wilted. Quantitative real-time PCR showed that the expression levels of target genes were significantly reduced in the RNAi-treated groups compared with those of the control, suggesting that all three types of RNAi herbicides effectively silenced the endogenous target genes, which are essential for the growth of M. micrantha . We also found that shRNA showed better silencing efficiency than the other two molecules. Taken together, our study successfully designed three types of RNAi-based herbicides that specifically silenced endogenous target genes and controlled the growth of M. micrantha. Moreover, we identified a gene family encoding chlorophyll a/b-binding proteins that is important for the growth and development of M. micrantha and could serve as potential targets for controlling the spread of M. micrantha.

High-quality chromosome-level scaffolds of the plant bug Pachypeltis micranthus provide insights into the availability of Mikania micrantha control

“…S10b). Hence, it is possible to further screen P. micranthus PG with specific control capabilities against M. micrantha and develop environmentally friendly, safe, and specific RNA interference (RNAi) herbicides based on shRNA [ 142 ] for the targeted control of M. micrantha .…”

Designer antisense circRNAGFPreduces GFP protein abundance in transgenic Arabidopsis protoplasts in a sequence-specific manner, independent of RNAi pathways

“…Apart from the promising undertakings in human medicine (Kim 2022; Zhu et al 2022), there is growing evidence that different types of RNA molecules can also be used to control plant pests, microbial pathogens and weeds (Banerjee et al, 2017; Baulcombe, 2015; Cai et al, 2018; Koch and Wassenegger, 2021; Mai et al, 2021; Taning et al, 2019; Liu et al, 2020). In agricultural research, strong efforts have been taken to develop non-GMO plant protection measures based on the exogenous application of RNA (SIGS) with some success (Huang et al, 2023; Koch et al, 2016; Niehl et al, 2018; Wang et al, 2016; Zabala-Pardo et al, 2022).…”

“…In the context of crop protection, the use of RNA for the targeted control of plant genes offers several potential applications, including its use as herbicide or as antimicrobial agent when targeting plant susceptibility genes (Mai et al, 2021; van Schie et al, 2014). However, the efficiency of exogenous RNA applications such as dsRNA or sRNA so far is hampered by its low stability under agronomic conditions and its weak uptake by leaves (Bennett et al, 2020; Dalakouras et al, 2016; 2020; Liu et al, 2021).…”

“…In addition to its main use as a biological control agent against microbial pathogens and animal pests, there is growing interest in exploring the potential use of RNA for weed control (Mai et al, 2021; Zabala-Pardo et al, 2022). However, there are challenges for using SIGS as a practical tool for weed management.…”

Can nanotechnology improve the application of bioherbicides?

“…42 In addition, to avoid orthologous gene silencing in crops closely related to weeds, recognition molecules as described above could be used to attach nanocarriers specifically to the target weeds. Coupled with recent advances in RNAi targeting invasive plants, 43 this provides a favourable setting for the development of bioherbicides based on gene silencing with nucleic acids. Furthermore, microorganisms such as bacteria or viruses could be modified to synthesize siRNA and used as control agents against weeds; however, this strategy would need regulatory approval and face commercialization problems related to genetically modified organisms (GMOs), among others, so it does not seem practical at this time.…”