MtNAD1 associates with the autophagy complex to contribute to the degradation of immunity-related proteins in Medicago truncatula nodules.

Plant immunity is suppressed in the symbiotic nodule cells, thereby facilitating rhizobial infection. Medicago truncatula NODULES WITH ACTIVATED DEFENSE1 (MtNAD1) is crucial for suppressing immunity in nodules; however, its molecular function is unclear. We explored the molecular basis of the role of MtNAD1 in suppressing innate immunity in M.

Conserved cis-elements enable NODULES WITH ACTIVATED DEFENSE1 regulation by NODULE INCEPTION during nodulation.

Symbiotic nitrogen fixation within nitrogen-fixing clade (NFC) plants is thought to have arisen from a single gain followed by massive losses in the genomes of ancestral non-nodulating plants. However, molecular evidence supporting this model is limited. Here, we confirm through bioinformatic analysis that NODULES WITH ACTIVATED DEFENSE1 (NAD1) is present only in NFC plants and is thus an NFC-specific gene.

Soybean ethylene response factors GmENS1 and GmENS2 promote nodule senescence.

The final phase in root nodule development is nodule senescence. The mechanism underlying the initiation of nodule senescence requires further elucidation. In this study, we investigate the intrinsic signals governing soybean (Glycine max L.

NODULATION TRIO in Medicago truncatula: Unveiling the redundant roles of MtLYK2, MtLYK3, and MtLYK2bis.

Three Medicago truncatula LysM domain receptor kinases have redundant functions in nodulation, with multiple specificities mediating both entry and signaling responses and with distinct contributions to nodulation likely resulting from differing transcription patterns.

A soybean cyst nematode suppresses microbial plant symbionts using a lipochitooligosaccharide-hydrolysing enzyme.

Cyst nematodes are the most damaging species of plant-parasitic nematodes. They antagonize the colonization of beneficial microbial symbionts that are important for nutrient acquisition of plants. The molecular mechanism of the antagonism, however, remains elusive.

Dynamic modulation of nodulation factor receptor levels by phosphorylation-mediated functional switch of a RING-type E3 ligase during legume nodulation.

The precise control of receptor levels is crucial for initiating cellular signaling transduction in response to specific ligands; however, such mechanisms regulating nodulation factor (NF) receptor (NFR)-mediated perception of NFs to establish symbiosis remain unclear. In this study, we unveil the pivotal role of the NFR-interacting RING-type E3 ligase 1 (NIRE1) in regulating NFR1/NFR5 homeostasis to optimize rhizobial infection and nodule development in Lotus japonicus. We demonstrated that NIRE1 has a dual function in this regulatory process.

A pathogenesis-related protein, PRP1, negatively regulates root nodule symbiosis in Lotus japonicus.

The legume-rhizobium symbiosis represents a unique model within the realm of plant-microbe interactions. Unlike typical cases of pathogenic invasion, the infection of rhizobia and their residence within symbiotic cells do not elicit a noticeable immune response in plants. Nevertheless, there is still much to uncover regarding the mechanisms through which plant immunity influences rhizobial symbiosis.

Wild species rice -mediated arbuscular mycorrhiza symbiosis boosts yield and nutrient use efficiency in rice breeding.

Unlabelled: Meeting the ever-increasing food demands of a growing global population while ensuring resource and environmental sustainability presents significant challenges for agriculture worldwide. Arbuscular mycorrhizal symbiosis (AMS) has emerged as a potential solution by increasing the surface area of a plant's root system and enhancing the absorption of phosphorus, nitrogen nutrients, and water. Consequently, there is a longstanding hypothesis that rice varieties exhibiting more efficient AMS could yield higher outputs at reduced input costs, paving the way for the development of Green Super Rice (GSR).

Mitogen-activated protein kinases MPK3 and MPK6 phosphorylate receptor-like cytoplasmic kinase CDL1 to regulate soybean basal immunity.

Soybean cyst nematode (SCN; Heterodera glycines Ichinohe), one of the most devastating soybean (Glycine max) pathogens, causes significant yield loss in soybean production. Nematode infection triggers plant defense responses; however, the components involved in the upstream signaling cascade remain largely unknown. In this study, we established that a mitogen-activated protein kinase (MAPK) signaling module, activated by nematode infection or wounding, is crucial for soybeans to establish SCN resistance.

Dual RNA-Seq Analysis Pinpoints a Balanced Regulation between Symbiosis and Immunity in - Symbiotic Nodules.

Legume-rhizobial symbiosis initiates the formation of root nodules, within which rhizobia reside and differentiate into bacteroids to convert nitrogen into ammonium, facilitating plant growth. This process raises a fundamental question: how is plant immunity modulated within nodules when exposed to a substantial number of foreign bacteria? In , a mutation in the () gene exclusively results in the formation of necrotic nodules combined with activated immunity, underscoring the critical role of in suppressing immunity within nodules. In this study, we employed a dual RNA-seq transcriptomic technology to comprehensively analyze gene expression from both hosts and symbionts in the mutant nodules at different developmental stages (6 dpi and 10 dpi).

GmNAC039 and GmNAC018 activate the expression of cysteine protease genes to promote soybean nodule senescence.

Root nodules are major sources of nitrogen for soybean (Glycine max (L.) Merr.) growth, development, production, and seed quality.

A novel secreted protein, NISP1, is phosphorylated by soybean Nodulation Receptor Kinase to promote nodule symbiosis.

Nodulation Receptor Kinase (NORK) functions as a co-receptor of Nod factor receptors to mediate rhizobial symbiosis in legumes, but its direct phosphorylation substrates that positively mediate root nodulation remain to be fully identified. Here, we identified a GmNORK-Interacting Small Protein (GmNISP1) that functions as a phosphorylation target of GmNORK to promote soybean nodulation. GmNORKα directly interacted with and phosphorylated GmNISP1.

The Perspective of Arbuscular Mycorrhizal Symbiosis in Rice Domestication and Breeding.

In nature, symbiosis with arbuscular mycorrhizal (AM) fungi contributes to sustainable acquisition of phosphorus and other elements in over 80% of plant species; improving interactions with AM symbionts may mitigate some of the environmental problems associated with fertilizer application in grain crops such as rice. Recent developments of high-throughput genome sequencing projects of thousands of rice cultivars and the discovery of the molecular mechanisms underlying AM symbiosis suggest that interactions with AM fungi might have been an overlooked critical trait in rice domestication and breeding. In this review, we discuss genetic variation in the ability of rice to form AM symbioses and how this might have affected rice domestication.

Suppression of LjBAK1-mediated immunity by SymRK promotes rhizobial infection in Lotus japonicus.

An important question in biology is how organisms can associate with different microbes that pose no threat (commensals), pose a severe threat (pathogens), and those that are beneficial (symbionts). The root nodule symbiosis serves as an important model system for addressing such questions in the context of plant-microbe interactions. It is now generally accepted that rhizobia can actively suppress host immune responses during the infection process, analogous to the way in which plant pathogens can evade immune recognition.

Critical role of cysteine-266 of SIE3 in regulating the ubiquitination and degradation of SIP1 transcription factor in Lotus japonicus.

A conserved cysteine residue (C266)-mediated homo-dimerization of SIE3 is required for the ubiquitination and degradation of SIP1 transcription factor in Lotus japonicas CTLH/CRA/RING-containing proteins have been shown to possess E3-ligase activities and are crucial for the regulation of numerous cellular signaling pathways. In our previous studies, SIE3 (SymRK-Interacting E3 ubiquitin ligase), a CTLH/CRA/RING-containing protein from Lotus japonicus, has been shown to associate with both Symbiosis Receptor Kinase (SymRK) and SIP1 (SymRK interacting protein 1) transcription factor, and ubiquitinate SymRK (Yuan et al. Plant Physiol 160 (1):106-117, 2012; Feng et al.

New insights into the function of the proteins IsiC and IsiD from Synechocystis sp. PCC 6803 under iron limitation.

Iron is a common cofactor in biological processes such as respiration, photosynthesis, and nitrogen fixation. The genes isiC and isiD encode unknown proteins, and the growth of ΔisiC and ΔisiD mutants is inhibited under iron-deficient conditions. To study the regulatory mechanisms of IsiC and IsiD during iron starvation, we carried out transcriptome and metabolome sequencing.

Phosphorylation of ATG18a by BAK1 suppresses autophagy and attenuates plant resistance against necrotrophic pathogens.

Autophagy is critical for plant defense against necrotrophic pathogens, which causes serious yield loss on crops. However, the post-translational regulatory mechanisms of autophagy pathway in plant resistance against necrotrophs remain poorly understood. In this study, we report that phosphorylation modification on ATG18a, a key regulator of autophagosome formation in , constitutes a post-translation regulation of autophagy, which attenuates plant resistance against necrotrophic pathogens.

The Ubiquitin Ligase SIE3 Interacts With the Transcription Factor SIP1 and Forms a Homodimer.

The symbiosis receptor kinase SymRK plays an essential role in symbiotic signal transduction and nodule organogenesis. Several proteins bind to SymRK, but how the symbiosis signals are transduced from SymRK to downstream components remains elusive. We previously demonstrated that both SymRK interacting protein 1 (SIP1, an ARID-type DNA-binding protein) and SymRK interacting E3 ligase [SIE3, a RING (Really Interesting New Gene)-containing E3 ligase] interact with SymRK to regulate downstream cellular responses in during the legume-rhizobia symbiosis.

CPK5 Phosphorylates the Chitin Receptor LYK5 to Regulate Plant Innate Immunity.

Chitin, a major component of the fungal cell wall, triggers plant innate immunity in a receptor complex including two major lysin motif receptor-like kinases, AtLYK5, and AtCERK1. Although AtLYK5 has been proposed to be a major chitin-binding receptor, the pseudokinase domain of AtLYK5 is required to mediate chitin-triggered immune responses in plants. In this study, 48 AtLYK5-interacting proteins were identified using immunoprecipitation and mass spectrometry assay.

A High-Quality Genome Sequence of Model Legume (MG-20) Provides Insights into the Evolution of Root Nodule Symbiosis.

is an important model legume for studying symbiotic nitrogen fixation as well as plant development. A genomic sequence of (MG20) has been available for more than ten years. However, the low quality of the genome limits its application in functional genomic studies.

Transcriptional regulation of NIN expression by IPN2 is required for root nodule symbiosis in Lotus japonicus.

Expression of Nodule Inception (NIN) is essential for initiation of legume-rhizobial symbiosis. An existing model regarding the regulation of NIN expression involves two GRAS transcription factors - NSP1 (Nodulation Signaling Pathway 1) and NSP2. NSP2 forms a complex with NSP1 to directly bind to NIN promoter.

Natural variation at OsCERK1 regulates arbuscular mycorrhizal symbiosis in rice.

The symbiotic interaction between arbuscular mycorrhizal fungi (AMF) and land plants is essential for efficient nutrient acquisition and utilisation. Our understanding of key processes controlling the AMF colonisation in rice is still limited. Dongxiang wild rice (DY) exhibited a stronger colonisation with Rhizophagus irregularis than the rice cultivar Zhongzao 35 (ZZ35).

Immune Signaling Pathway during Terminal Bacteroid Differentiation in Nodules.

Plant innate immunity plays an important role in regulating symbiotic associations with rhizobia, including during rhizobial infection, rhizobial colonization, and bacteroid differentiation in leguminous plants. Here we propose that an immune signaling pathway similar to plant pattern-triggered immunity (PTI) is required for the regulation of bacteroid differentiation in Medicago truncatula nodules.