Spray-Induced Gene Silencing as a Potential Tool to Control Potato Late Blight Disease

Abstract

Phytophthora infestans causes late blight disease on potato and tomato and is currently controlled by resistant cultivars or intensive fungicide spraying. Here, we investigated an alternative means for late blight control by spraying potato leaves with double-stranded RNAs (dsRNA) that target P. infestans genes that are essential for infection. First, we showed that the sporangia of P. infestans expressing Green Fluorescent Protein (GFP) can take up in vitro synthesized dsRNAs homologous to GFP directly from their surroundings, including leaves, which led to the reduced relative expression of GFP. We further demonstrate the potential of spray induced gene silencing (SIGS) in controlling potato late blight disease by targeting developmentally important genes in P.infestans such as guanine-nucleotide binding (G) protein β-subunit (PiGPB1), haustorial membrane protein (PiHmp1), cutinase (PiCut3), and endo-1,3(4)-β-glucanase (PiEndo3). Our results demonstrate that SIGS can potentially be used to mitigate potato late blight; however, the degree of disease control is dependent on the selection of the target genes.

Plant Growth-Promoting Activity of Pseudomonas aeruginosa FG106 and Its Ability to Act as a Biocontrol Agent against Potato, Tomato and Taro Pathogens

“…Control leaves were treated with 20 μL 1× PBS buffer instead of a pathogen suspension. This experiment was repeated three times with 5 leaves per treatment and two spots per leaf [ 60 , 61 ].…”

Spray-induced gene silencing: an innovative strategy for plant trait improvement and disease control

“…Using a similar approach, exogenously applied dsRNAs did not lead to RNAi of target genes in the potato late blight pathogen, Phytophthora infestans (Qiao et al 2021). However, by spray application of dsRNAs onto potato leaves, another study demonstrated that dsRNAs targeting developmentally important pathogen genes coding for guanine-nucleotide binding (G) protein β-subunit (PiGPB1), haustorial membrane protein (PiHMP1), cutinase (PiCUT3), or endo-1,3(4)-βglucanase (PiENDO3) in P. infestans can potentially be used as a tool in controlling potato late blight disease (Kalyandurg et al 2021). These results suggest that the optimal outcomes for SIGS against oomycete pathogens may be strongly influenced by the manner in which the dsRNA is applied.…”

Roles of small RNAs in crop disease resistance

“…SIGS of F. graminearum AGO and DCL genes protects barley leaves from F. graminearum infection (Werner et al 2020). Moreover, SIGS has been adopted to compromise Verticillium wilt in tomato (Song and Thomma 2018) and late blight disease in potato (Kalyandurg et al 2021). It is needed to note that the efficiency of SIGS for disease control largely depends on the efficiency of RNA uptake by pathogens and the secondary amplification of siRNA machinery (Qiao et al 2021;Song and Thomma 2018).…”

“…For example, a major hurdle in the practical application of SIGS is the rapid degradation of naked RNAs. To overcome this problem, nanomaterials such as chitosan-complexed single-walled carbon nanotubes (Demirer et al 2019;Kwak et al 2019) and layered double hydroxide (LDH) clay nanosheets (Qiao et al 2021), may be used to deliver and stabilize sRNAs. These new approaches not only facilitate biomolecule transport into plant cells with high efficiency and without toxicity or tissue damage but also protect RNA cargo from nuclease degradation.…”

“…Whether artificial EVs can function in vivo still needs to be investigated. Despite efficient dsRNA uptake in many fungal plant pathogens have been achieved, the efficiency of dsRNAs uptake in other fungi still need to be resolved (Qiao et al 2021;Rosa et al 2018). Moreover, strategies for control bacteriainduced diseases are rather limited.…”