Development of nematode resistance in Arabidopsis by HD-RNAi-mediated silencing of the effector gene Mi-msp2

Abstract

Root-knot nematodes (RKNs) are devastating parasites that infect thousands of plants. As RKN infection is facilitated by oesophageal gland effector genes, one such effector gene, Mi-msp2, was selected for a detailed characterization. Based on domain analysis, the Mi-MSP2 protein contains an ShKT domain, which is likely involved in blocking K+ channels and may help in evading the plant defence response. Expression of the Mi-msp2 gene was higher in juveniles (parasitic stage of RKNs) than in eggs and adults. Stable homozygous transgenic Arabidopsis lines expressing Mi-msp2 dsRNA were generated, and the numbers of galls, females and egg masses were reduced by 52–54%, 60–66% and 84–95%, respectively, in two independent RNAi lines compared with control plants. Furthermore, expression analysis revealed a significant reduction in Mi-msp2 mRNA abundance (up to 88%) in female nematodes feeding on transgenic plants expressing dsRNA, and northern blot analysis confirmed expression of the Mi-msp2 siRNA in the transgenic plants. Interestingly, a significant reduction in the reproduction factor was observed (nearly 40-fold). These data suggest that the Mi-msp2 gene can be used as a potential target for RKN management in crops of economic importance.

The Meloidogyne javanica effector Mj2G02 interferes with jasmonic acid signalling to suppress cell death and promote parasitism in Arabidopsis

“…Similarly, fewer galls, females, and egg masses were observed in transgenic Arabidopsis lines expressing Mi-msp2 (an Mj2G02 ortholog) dsRNA than control plants (Joshi et al, 2019). Taken together, these results strongly suggest that Mj2G02 plays a role in nematode invasion and the early stages of parasitism, promoting infection by M. javanica.…”

“…More importantly, Mj2G02 ‐transgenic Arabidopsis plants were more susceptible to M. javanica infection than controls and, conversely, in planta RNAi silencing of Mj2G02 significantly increased the plant resistance to M. javanica . Similarly, fewer galls, females, and egg masses were observed in transgenic Arabidopsis lines expressing Mi‐msp2 (an Mj2G02 ortholog) dsRNA than control plants (Joshi et al, 2019 ). Taken together, these results strongly suggest that Mj2G02 plays a role in nematode invasion and the early stages of parasitism, promoting infection by M. javanica .…”

Tomato Divinyl Ether-Biosynthesis Pathway Is Implicated in Modulating of Root-Knot Nematode Meloidogyne javanica's Parasitic Ability

“…To test the response of transgenic Arabidopsis plants to nematode infection, three transgenic lines were used, 10 plants per line in each experiment. Seeds of WT, vector-only and transgenic Arabidopsis lines were surface sterilized and germinated on standard-strength GB media with 2% (w/v) sucrose and 0.8% (w/v) Gelrite as described previously by Joshi et al ( 2019 ). One-week-old seedlings grown in vitro were gently transferred with a forceps to a petri dish containing GB media, one plant per dish.…”

New genetic tools for plant defense against parasitic nematodes

“…Интересные результаты получены при попытке использования HIGS в качестве мишени гена M. incognita, кодирующего PPNэффектор MiMSP2, участвующий в супрессии защитного ответа растенияхозяина. Трансгенные растения, экспрессирующие такие дцРНК, характеризовались сниженной на 88 % экспрессией генамишени у самок нематоды, а также уменьшенной на 80 % продукцией яиц (Joshi et al, 2019). Применение этой технологии для защиты растений баклажана показало, что дцРНК стабильно экспрессировалась в трансгенных формах вплоть до третьего поколения от самоопыления и обеспечивала высокий уровень защиты от нематоды (Chaudhary et al, 2019).…”