Biology subjects

Zuccaro, A.

Publications and source records attributed to Zuccaro, A..

22 records · Page 2Linked to original sources

bioRxiv2021

The fungal root endophyte Serendipita vermifera displays inter-kingdom synergistic beneficial effects with the microbiota in Arabidopsis thaliana and barley

Plant root-associated bacteria can confer protection against pathogen infection. By contrast, the beneficial effects of root endophytic fungi and their synergistic interactions with bacteria remain poorly defined. We demonstrate that the combined action of a fungal root endophyte from a widespread taxon with core bacterial microbiota members provides synergistic protection against an aggressive soil-borne pathogen in Arabidopsis thaliana and barley. We additionally show early inter-kingdom growth promotion benefits which are host and microbiota composition dependent. HighlightsO_LIThe root endophytic fungus Serendipita vermifera can functionally replace core bacterial microbiota members in mitigating pathogen infection and disease symptoms. C_LIO_LIS. vermifera additionally stabilizes and potentiates the protective activities of root-associated bacteria and mitigates the negative effects of a non-native bacterial community in A. thaliana. C_LIO_LIInter-kingdom synergistic beneficial effects do not require extensive host transcriptional reprogramming nor high levels of S. vermifera colonisation. C_LIO_LIInter-kingdom protective benefits are largely independent of the host while synergism leading to early inter-kingdom growth promotion is driven by host species and microbiota composition. C_LI

plant biology↗

bioRxiv2021

The intrinsic chaperone network of Arabidopsis stem cells confers protection against proteotoxic stress

The biological purpose of plant stem cells is to maintain themselves while providing new pools of differentiated cells that form organs and rejuvenate or replace damaged tissues1-3. Protein homeostasis, or proteostasis, is required for cell function and viability4-7. However, the link between proteostasis and plant stem cell identity remains unknown. In contrast to their differentiated counterparts, we find that root stem cells can prevent the accumulation of aggregated proteins even under proteotoxic stress conditions such as heat stress or proteasome inhibition. Notably, root stem cells exhibit enhanced expression of distinct chaperones that maintain proteome integrity. Particularly, intrinsic high levels of the TRiC/CCT chaperonin determine stem cell maintenance and their remarkable ability to suppress protein aggregation. Overexpression of CCT8, a key activator of TRiC/CCT assembly8, is sufficient to ameliorate protein aggregation in differentiated cells and confer resistance to proteotoxic stress in plants. Taken together, our results indicate that enhanced proteostasis mechanisms in stem cells could be an important requirement for plants to persist under extreme environmental conditions and reach extreme long ages. Thus, proteostasis of stem cells could provide insights to design and breed plants tolerant to environmental challenges caused by the climate change.

plant biology↗

bioRxiv2019

A secreted LysM effector protects fungal hyphae through chitin-dependent homodimer polymerization

Plants trigger immune responses upon recognition of fungal cell wall chitin, followed by the release of various antimicrobials, including chitinase enzymes that hydrolyze chitin. In turn, many fungal pathogens secrete LysM effectors that prevent chitin recognition by the host through scavenging of chitin oligomers. We previously showed that intrachain LysM dimerization of the Cladosporium fulvum effector Ecp6 confers an ultrahigh-affinity binding groove that competitively sequesters chitin oligomers from host immune receptors. Additionally, particular LysM effectors are found to protect fungal hyphae against chitinase hydrolysis during host colonization. However, the molecular basis for the protection of fungal cell walls against hydrolysis remained unclear. Here, we determined a crystal structure of the single LysM domain-containing effector Mg1LysM of the wheat pathogen Zymoseptoria tritici and reveal that Mg1LysM is involved in the formation of two kinds of dimers; a chitin-dependent dimer as well as a chitin-independent homodimer. In this manner, Mg1LysM gains the capacity to form a supramolecular structure by chitin-induced oligomerization of chitin-independent Mg1LysM homodimers, a property that confers protection to fungal cell walls against host chitinases.

microbiology↗

bioRxiv2018

The fungal root endophyte Serendipita indica modifies extracellular nucleotides to subvert plant immunity

One sentence abstractImmune modulation by metabolites in plant fungus interaction\n\nAbstractExtracellular adenosine 5'-triphosphate (eATP) is an essential signaling molecule that mediates different cellular processes through its interaction with membrane-associated receptor proteins in animals and plants. eATP regulates plant growth, development and responses to biotic and abiotic stresses. Its accumulation in the apoplast induces ROS production and cytoplasmic calcium increase mediating a defense response to invading microbes. We demonstrate that perception of eATP is important in plant-fungus interaction and that during colonization by the beneficial root endophyte Serendipita indica accumulation of eATP in the apoplast occurs at early symbiotic stages. We show by liquid chromatography-tandem mass spectrometry, cytological and functional analysis that S. indica subvert eATP host response by secreting SiE5NT, an enzymatically active ecto-5'nucleotidase capable of hydrolyzing eATP to adenosine. A. thaliana lines producing extracellular SiE5NT are signi?cantly better colonized and have reduced eATP levels and defense signaling, indicating that SiE5NT functions as a compatibility factor. Our data show that extracellular bioactive nucleotides play an important role in fungus-root interactions and that fungi can modify plant derived metabolites in the apoplast to modulate host immunity.

plant biology↗