Resistance to root‐knot nematodes Meloidogyne spp. in woody plants

Abstract

Summary Root‐knot nematodes (RKNs) Meloidogyne spp. cause major damage to cultivated woody plants. Among them, Prunus, grapevine and coffee are the crops most infested by worldwide polyphagous species and species with a more limited distribution and/or narrower host range. The identification and characterization of natural sources of resistance are important steps to develop RKN control strategies. In woody crops, resistant rootstocks genetically different from the scion of agronomical interest may be engineered. We describe herein the interactions between RKNs and different woody crops, and highlight the plant species in which resistance and corresponding resistance (R) genes have been discovered. Even though grapevine and, to a lesser extent, coffee have a history of rootstock selection for RKN resistance, few cases of resistance have been documented. By contrast, in Prunus, R genes with different spectra have been mapped in plums, peach and almond and can be pyramided for durable resistance in interspecific rootstocks. We particularly discuss here the Ma Toll/interleukin‐1 receptor‐like‐nucleotide binding‐leucine‐rich repeat gene from Myrobalan plum, one of the longest plant R genes cloned to date, due to its unique biological and structural properties. RKN R genes in Prunus will enable us to carry out molecular studies aimed at improving our knowledge of plant immunity in woody plants.

Transcriptomic and histological responses of African rice (Oryza glaberrima) to Meloidogyne graminicola provide new insights into root-knot nematode resistance in monocots

“…Transmission electron microscopy has proved to be a valuable tool to visualize ultrastructural changes in GCs or cells in close vicinity to the nematode, typical of an hypersensitive response (HR) cell death phenotype, including cytoplasmic shrinkage, chromatin condensation, mitochondrial swelling, and chloroplast disruption combined with vacuolization (Coll et al, 2011). Transmission electron microscopy could verify that resistance in African rice to M. graminicola is characterized by HR or HR-like responses, as occurs in other plant species, including tomato (Bleve-Zacheo et al, 1982), coffee (Anthony et al, 2005;Albuquerque et al, 2010), grapevine (Anwar and McKenry, 2002), pepper (Bleve-Zacheo et al, 1998), resistant Ma plums (Saucet et al, 2016) and wild grasses (Balhadère and Evans, 1995). In these resistant species, the HR is usually efficient in stopping nematode development (Albuquerque et al, 2010;Bleve-Zacheo et al, 1982, 1998Khallouk et al, 2011) or is accompanied by poor development of nutrient feeding sites (Anthony et al, 2005;Fourie et al, 2013).…”

Evaluation of the Phytopathological Reaction of Wild and Cultivated Olives as a Means of Finding Promising New Sources of Genetic Diversity for Resistance to Root-Knot Nematodes

“…Perennial plants such as the olive present a particular challenge for combating infection. Resistance genes are exposed to much longer periods of continual pressure than plants in annual production systems (Saucet et al 2016), increasing the risk that nematodes will 'break' the plant resistance (Lespinasse et al 2003). Nematicides are restricted in their use in woody plants and in a low-income crop such as olive are not economically feasible, thus alternative control measures are required.…”

Crotalaria and millet as alternative controls of root-knot nematodes infecting okra

“…Root-knot nematodes (Meloidogyne spp.) are considered, among all plant-parasitic nematodes, to be the main agents that damage crops worldwide (SAUCET et al, 2016). In tropical climates, they are even more menacing, as the environmental conditions favor their development and reproduction (HUSSAIN et al, 2012).…”