SlWRKY45 interacts with jasmonate-ZIM domain proteins to negatively regulate defense against the root-knot nematodeMeloidogyne incognitain tomato

Abstract

Parasitic root-knot nematodes (RKNs) cause a severe reduction in crop yield and seriously threaten agricultural production. The phytohormones jasmonates (JAs) are important signals regulating resistance to multiple biotic and abiotic stresses. However, the molecular mechanism for JAs-regulated defense against RKNs in tomato remains largely unclear. In this study, we found that the transcription factor SlWRKY45 interacted with most JA-ZIM domain family proteins (JAZs), key repressors of the JA signaling. After infection by the RKN Meloidogyne incognita, the slwrky45 mutants exhibited lower gall numbers and egg numbers per gram of roots than wild type, whereas overexpression of SlWRKY45 attenuated resistance to M. incognita. Under M. incognita infection, the contents of jasmonic acid (JA) and JA-isoleucine (JA-Ile) in roots were repressed by SlWRKY45-overexpression. Furthermore, SlWRKY45 bound to and inhibited the promoter of the JA biosynthesis gene ALLENE OXIDE CYCLASE (AOC), and repressed its expression. Overall, our findings revealed that the SlJAZ-interaction protein SlWRKY45 attenuated RKN-regulated JA biosynthesis and repressed defense against the RKN M. incognita in tomato.

Reference genes identification for qRT-PCR normalization of gene expression analysis in Cucumis sativus under Meloidogyne incognita infection and Pseudomonas treatment

“…research, ACT has been employed to normalize gene expression in several species infected by nematode, including Arabidopsis and tomato (Hewezi et al, 2010;Uehara et al, 2010;Vijayapalani et al, 2018;Xu et al, 2019;Huang et al, 2022), although none of the research involves HKGs screening in nematode infection experiment. It might be reasonable to speculate that ACT can be used as a universal HKG to normalize gene expression level in different species under nematode infection treatment.…”

“…In addition, ACT are suitable reference genes in root knot and whole root samples after M. incognita infection, but they were not suitable for a reference gene under Pseudomonas treatment ( Table 4 , Figure 3 ). In previous research, ACT has been employed to normalize gene expression in several species infected by nematode, including Arabidopsis and tomato ( Hewezi et al., 2010 ; Uehara et al., 2010 ; Vijayapalani et al., 2018 ; Xu et al., 2019 ; Huang et al., 2022 ), although none of the research involves HKGs screening in nematode infection experiment. It might be reasonable to speculate that ACT can be used as a universal HKG to normalize gene expression level in different species under nematode infection treatment.…”

The SlWRKY57‐SlVQ21/SlVQ16 module regulates salt stress in tomato

“…To generate slwrky57, slvq16 , and slvq21 mutants, two targets for SlWRKY57 and SlVQ21 , and one target for SlVQ16 indicated in Figures S2A, S10A, and S7A respectively, were selected and cloned into a pCBSG012 vector for genome editing (Huang et al, 2022a). The recombinant construct was transferred into Agrobacterium GV3101 to produce CRISPR‐ Cas9 gene edited mutants.…”

An emergent plant‐parasitic nematode in Brazil: Aphelenchoides besseyi. Current status and research perspectives

“…Deleting or altering so-called susceptibility genes (S genes) within the host that the pathogen relies on for successfully infecting the plant can give rise to novel sources of resistance. For example, SlWRKY45, a negative regulator of jasmonic acid signalling, is targeted by M. incognita and deleting the gene by CRISPR/Cas9 leads to a reduction in gall index and nematode number (Huang et al, 2022). Another example is that of the metabolic pathway for vitamin B5 synthesis, which is incomplete in the beet cyst nematode H. schachtii, and the nematode depends on the host plant for the early steps of the pathway.…”

“…Among them, six had an unknown role, whereas the other seven presented varied functions, such as protein degradation and binding of host fatty acids (Wang et al, 2014). Huang et al (2022) investigated the role of a new effector in rice parasitism, a serine carboxypeptidase termed AbSCP1.…”