Cross-kingdom vitamin B5 biosynthesis and cyst nematode susceptibility

Plant effectostimulins and nematode SUbventral-Gland Regulator promote parasitism

Plant parasitic nematodes secrete effectors to promote disease progression. However, the mechanisms by which plant hosts and nematodes trigger the expression of these effector genes remain elusive. Recently, Pellegrin et al. discovered that plant-derived stimulants and the nematode SUbventral-Gland Regulator aid in the activation of effector genes in cyst nematodes.

Comparative Transcriptomic Analysis of Soybean Cyst Nematode Inbred Populations Non-adapted or Adapted on Soybean rhg1-a/Rhg4-Mediated Resistance

Soybean cyst nematode (SCN, Heterodera glycines) is most effectively managed through planting resistant soybean cultivars, but the repeated use of the same resistance sources has led to a widespread emergence of virulent SCN populations that can overcome soybean resistance. Resistance to SCN HG type 0 (Race 3) in soybean cultivar Forrest is mediated by an epistatic interaction between the soybean resistance genes rhg1-a and Rhg4. We previously developed two SCN inbred populations by mass-selecting SCN HG type 0 (Race 3) on susceptible and resistant recombinant inbred lines, derived from a cross between Forrest and the SCN-susceptible cultivar Essex, which differ for Rhg4. To identify SCN genes potentially involved in overcoming rhg1-a/Rhg4-mediated resistance, we conducted RNA sequencing on early parasitic juveniles of these two SCN inbred populations infecting their respective hosts, only to discover a handful of differentially expressed genes (DEGs). However, in a comparison with early parasitic juveniles of an avirulent SCN inbred population infecting a resistant host, we discovered 59 and 171 DEGs uniquely up- or downregulated in virulent parasitic juveniles adapted on the resistant host. Interestingly, the proteins coded by these 59 DEGs included vitamin B-associated proteins (reduced folate carrier, biotin synthase, and thiamine transporter) and nematode effectors known to play roles in plant defense suppression, suggesting that virulent SCN may exert a heightened transcriptional response to cope with enhanced plant defenses and an altered nutritional status of a resistant soybean host. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Parasitic nematodes: dietary habits and their implications

Nematodes, a diverse group of roundworms, exhibit a wide range of dietary habits, including parasitism of animals and plants. These parasites cause substantial economic losses in agriculture and pose significant health challenges to humans and animals. This review explores the unique adaptations of parasitic nematodes, emphasizing their nutritional requirements and metabolic dependencies. Recent research has identified cross-kingdom compartmentalization of vitamin B5 biosynthesis in some parasitic nematodes, shedding light on coevolutionary dynamics and potential targets for control strategies. Several open questions remain regarding the complexity of nematode nutrition, host manipulation, evolutionary adaptations, and the influence of environmental factors on their metabolic processes. Understanding these aspects offers promising avenues for targeted interventions to manage and control these economically and medically important parasites.