Pre-announcement of symbiotic guests: transcriptional reprogramming by mycorrhizal lipochitooligosaccharides shows a strict co-dependency on the GRAS transcription factors NSP1 and RAM1

BACKGROUND: More than 80 % of all terrestrial plant species establish an arbuscular mycorrhiza (AM) symbiosis with Glomeromycota fungi. This plant-microbe interaction primarily improves phosphate uptake, but also supports nitrogen, mineral, and water aquisition. During the pre-contact stage, the AM symbiosis is controled by an exchange of diffusible factors from either partner. Amongst others, fungal signals were identified as a mix of sulfated and non-sulfated lipochitooligosaccharides (LCOs), being structurally related to rhizobial nodulation (Nod)-factor LCOs that in legumes induce the formation of nitrogen-fixing root nodules. LCO signals are transduced via a common symbiotic signaling pathway (CSSP) that activates a group of GRAS transcription factors (TFs). Using complex gene expression fingerprints as molecular phenotypes, this study primarily intended to shed light on the importance of the GRAS TFs NSP1 and RAM1 for LCO-activated gene expression during pre-symbiotic signaling. RESULTS: We investigated the genome-wide transcriptional responses in 5 days old primary roots of the Medicago truncatula wild type and four symbiotic mutants to a 6 h challenge with LCO signals supplied at 10(-7/-8) M. We were able to show that during the pre-symbiotic stage, sulfated Myc-, non-sulfated Myc-, and Nod-LCO-activated gene expression almost exclusively depends on the LysM receptor kinase NFP and is largely controled by the CSSP, although responses independent of this pathway exist. Our results show that downstream of the CSSP, gene expression activation by Myc-LCOs supplied at 10(-7/-8) M strictly required both the GRAS transcription factors RAM1 and NSP1, whereas those genes either co- or specifically activated by Nod-LCOs displayed a preferential NSP1-dependency. RAM1, a central regulator of root colonization by AM fungi, controled genes activated by non-sulfated Myc-LCOs during the pre-symbiotic stage that are also up-regulated in areas with early physical contact, e.g. hyphopodia and infecting hyphae; linking responses to externally applied LCOs with early root colonization. CONCLUSIONS: Since both RAM1 and NSP1 were essential for the pre-symbiotic transcriptional reprogramming by Myc-LCOs, we propose that downstream of the CSSP, these GRAS transcription factors act synergistically in the transduction of those diffusible signals that pre-announce the presence of symbiotic fungi.DFG/SPP1212/KU-1478/4-1DFG/SPP1212/KU-1478/4-4DFG/SPP1212/KU-1478/4-2DFG/SPP1212/KU-1478/4-

Laser-microdissection unravels cell-type specific transcription in > arbuscular mycorrhizal roots, including CAAT-box TF gene expression correlating with fungal contact and spread

Arbuscular mycorrhizae (AM) are the most widespread symbioses on Earth, promoting nutrient supply of most terrestrial plant species. To unravel gene expression in defined stages of Medicago truncatula root colonization by AM fungi, we here combined genome-wide transcriptome profiling based on whole mycorrhizal roots with real-time RT-PCR experiments that relied on characteristic cell-types obtained via laser-microdissection. Our genome-wide approach delivered a core set of 512 genes significantly activated by the two mycorrhizal fungi Glomus intraradices and Glomus mossae. Focussing on 62 of these genes being related to membrane transport, signaling, and transcriptional regulation, we distinguished whether they are activated in arbuscule-containing or the neighbouring cortical cells harbouring fungal hyphae. In addition, cortical cells from non-mycorrhizal roots served as a reference for gene expression under non-colonized conditions. Our analysis identified 25 novel arbuscule-specific genes and 37 genes expressed both in the arbuscule-containing and the adjacent cortical cells colonized by fungal hyphae. Amongst the AM-induced genes specifying transcriptional regulators were two members encoding CAAT-box binding transcription factors (CBF), designated MtCbf1 and MtCbf2. Promoter analyses demonstrated that both genes were already activated by the first physical contact between the symbionts. Subsequently, and corresponding to our cell-type expression patterns, they were progressively up-regulated in those cortical areas colonized by fungal hyphae, including the arbuscule-containing cells. The encoded CBFs thus represent excellent candidates for regulators that mediate a sequential reprogramming of root tissues during the establishment of an AM symbiosi

National research: inclusion in Education

From April 6 to May 20 2024, the Croatian Shorthand Association conducted a national research study on inclusive education, focusing on the attitudes and perceptions of stakeholders within the educational process. The objective of the research was to identify key challenges faced by teachers, principals, and educational specialists and to provide recommendations for enhancing inclusive practices within the education system. A total of 268 actively employed individuals from various educational institutions in the Republic of Croatia participated, with data collected via a survey questionnaire.The results revealed that the majority of respondents are familiar with the concept of inclusive education and believe that their institutions encourage inclusive practices. However, some participants expressed concerns about the lack of resources and support for students with developmental difficulties. Additionally, many respondents recognized efforts by their institutions to provide special attention to students with difficulties, indicating a positive trend toward integrating these students. The research highlights existing challenges in implementing inclusive education and underscores the need for additional training and resources. These findings contribute to a better understanding of inclusive education and provide a foundation for developing strategies to improve practices within Croatia’s education system

Transesterifications in the Synthesis of Dinucleoside Phosphates Containing Dihydropyrimidine Nucleosides Residues

Synthesis of p-nitrophenyl-uridylyl-(5\u27-+5\u27)-5,6-dihydrouridine (V), thymidylyl-(3\u27-+5\u27)-uridine (XI), and fully protected thymiqylyl-( 3\u27-+5\u27)-5,6-dihydrouridine (XII) by transesterification method was described

Three philosophies of life

Članak nudi uvod i filozofski pristup biblijskim mudrosnim knjigama: Propovjedniku/Koheletu, Jobu i Pjesmi nad pjesmama. Ove tri knjige duboko su filozofske. Naposljetku i postoje samo tri filozofije života, a svaku od njih predstavljaju te knjige: život je ispraznost, život je trpljenje, život je ljubav. Ovo objašnjenje podsjeća na veliki Danteov ep Božanska komedija. Ljubav je naposljetku odgovor na Propovjednikovo traženje, alternativa ispraznosti, nadilaženje trpljenja i pravi smisao života. Te su knjige kratki sadržaj bogoslovnih kreposti vjere, ufanja i ljubavi te "osnovni sažetak duhovne povijesti svijeta".The article offers both an introductory as well as a philosophical approach to the biblical wisdom books of Ecclesiastes/Quoheleth, Job and Song of songs. These three books are indeed profound books of philosophy. Because there are ultimately only three philosophies of life and each one is represented by only these books of the Bible – life is vanity; life is suffering; life is love. This explanation is reminiscent of Dante’s great epic The Divine Comedy. Love is the ultimate answer to Ecclesiates’ quest, the alternative to vanity, the overcoming of suffering and the true meaning of life. These books are the epitome of the theological virtues of faith, hope and charity and “an essential summary of the spiritual history of the world”