Biology subjects

Binci, F.

Publications and source records attributed to Binci, F..

3 recordsLinked to original sources

bioRxiv2025

A symbiotic MLO gene regulates root development via RALF34-triggered Ca2+ signalling in Lotus japonicus

Mildew Locus O (MLO) genes, initially identified as powdery mildew susceptibility factors, are increasingly recognized as multifunctional regulators implicated in diverse processes, including plant reproduction, root thigmotropism, and interactions with beneficial microbes. Recent evidence shows that MLO proteins can act as Ca2+-permeable channels in response to Rapid Alkalinization Factors (RALF) peptides in reproductive cells, pointing to broader roles in Ca2+-mediated signalling. In this study, we investigate the symbiotic clade IV member LjMLO4 in the model legume Lotus japonicus, focusing on its role in root development and responsiveness to LjRALF34 peptides. We show that LjMLO4 expression is strongly induced in root cells colonized by arbuscular mycorrhizal (AM) fungi, yet loss-of-function mutants exhibit only subtle AM-associated phenotypes. Instead, we uncover a previously uncharacterized function of LjMLO4 as a regulator of primary root growth and lateral root formation, acting even in the absence of AM fungal colonization and in a Ca2+-dependent manner. Heterologous expression in E. coli confirms that LjMLO4 facilitates Ca2+ transport, while genetic and physiological assays demonstrate its contribution to LjRALF34-triggered root growth responses and Ca2+ signalling. Together, these findings identify LjMLO4 as a molecular hub between peptide signalling, Ca2+ transport and root system architecture, highlighting how MLO proteins integrate developmental, nutritional and symbiotic cues.

plant biology↗

bioRxiv2024

Modulatory effect of plasma-activated water on arbuscular mycorrhizal symbiosis in Lotus japonicus

Plasma-activated water (PAW) is a recently developed cutting-edge technology that is increasingly gaining interest for its applications in medicine, food industry and agriculture. In plant biology, PAW has been shown to promote seed germination, plant growth, and plant resistance to biotic and abiotic stresses. Despite increasing knowledge of the beneficial effects exerted by PAW on plants, little information is currently available about how this emerging technology may affect the mutualistic plant-microbe interactions in the rhizosphere. In this work we have investigated the impact of irrigation with PAW, generated by a plasma torch, on arbuscular mycorrhizal (AM) symbiosis between the model legume Lotus japonicus and the AM fungus Rhizophagus irregularis. Since PAW sensing by plants has recently been demonstrated to occur through calcium-mediated signalling, we monitored early cellular responses to different doses of PAW in L. japonicus roots expressing the Ca2+-sensitive photoprotein aequorin targeted to either the cytosol or nucleus. Quantitative analyses of AM fungal accommodation in host roots along with phosphate accumulation in leaves, as well as chemical analysis of N, C, S in shoots, showed that treatments with PAW play a modulatory role on plant AM symbiotic performance, in a manner dependent on the time interval of water exposure to the plasma and on the duration of plant irrigation treatment with PAW. Establishing a solid scientific ground for plasma-related technology may provide key elements to develop tools and treatments aimed to increase crop plant yield in a sustainable manner.

plant biology↗

bioRxiv2022

Multiphasic calcium signatures in the cytosol and nucleus of Lotus japonicus roots unlock the early discrimination of fungal signals

The recognition of different microbe-associated molecular patterns in the rhizosphere triggers in the plant root the activation of either an immune response or an accommodation program. In both types of responses, Ca2+ is a crucial intracellular messenger, mediating the early stages of the respective signalling pathways. In this work, we analysed the cytosolic and nuclear Ca2+ changes activated by a set of chitin-related oligomers in different genetic backgrounds of Lotus japonicus roots by using specifically targeted aequorin-based Ca2+ reporters. By means of pharmacological and genetic approaches, we dissected the Ca2+ signal into two temporally distinct components: a rapid initial transient, followed by a longer and milder elevation in Ca2+ concentration. Taking advantage of a complementary analysis using a cameleon-based bioassay in Medicago truncatula root organ cultures, we showed that the second phase can be interpreted as the Ca2+ spiking that is widely described in response to the perception of symbiotic signals. By contrast, the rapid first phase, critically dependent on elicitor concentration, was found to correlate with the activation of plant immunity marker genes. Overall, our study provides novel clues to a better understanding of the subtle boundaries between symbiotic and immunity responses in root-fungus interactions. HighlightIntracellular calcium changes induced in Lotus japonicus roots by fungal signals were dissected in two separate phases, relying on distinct genetic programs and differentially mediating plant symbiotic or immunity responses.

plant biology↗