The HY5-PIF regulatory module coordinates light and temperature control of photosynthetic gene transcription

The ability to interpret daily and seasonal alterations in light and temperature signals is essential for plant survival. This is particularly important during seedling establishment when the phytochrome photoreceptors activate photosynthetic pigment production for photoautotrophic growth. Phytochromes accomplish this partly through the suppression of phytochrome interacting factors (PIFs), negative regulators of chlorophyll and carotenoid biosynthesis. While the bZIP transcription factor long hypocotyl 5 (HY5), a potent PIF antagonist, promotes photosynthetic pigment accumulation in response to light. Here we demonstrate that by directly targeting a common promoter cis-element (G-box), HY5 and PIFs form a dynamic activation-suppression transcriptional module responsive to light and temperature cues. This antagonistic regulatory module provides a simple, direct mechanism through which environmental change can redirect transcriptional control of genes required for photosynthesis and photoprotection. In the regulation of photopigment biosynthesis genes, HY5 and PIFs do not operate alone, but with the circadian clock. However, sudden changes in light or temperature conditions can trigger changes in HY5 and PIFs abundance that adjust the expression of common target genes to optimise photosynthetic performance and growth

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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The SARS‑CoV‑2 frst wave impact in the acute infammatory surgical pathologies

Anecdotal evidence suggests that community infection control measures during the COVID19 outbreak have modifed the number and natural history of acute surgical infammatory processes (ASIP—appendicitis, cholecystitis, diverticulitis and perianal abscesses) admissions. This study aims to evaluate the impact of the COVID19 pandemic on the presentation and treatment ASIP and quantify the efect of COVID19 infection on the outcomes of ASIP patients. This was a multicentre, comparative study, whereby ASIP cases from 2019, 2020 and 2021 (March 14th to May 2nd) were analyzed. Data regarding patient and disease characteristics as well as outcomes, were collected from sixteen centres in Madrid, and one in Seville (Spain). The number of patients treated for ASIP in 2019 was 822 compared to 521 in 2020 and 835 in 2021. This 1/3rd reduction occurs mainly in patients with mild cases, while the number of severe cases was similar. Surgical standards sufered a step back during the frst wave: Lower laparoscopic approach and longer length of stay. We also found a more conservative approach to the patients this year, nonjustifed by clinical circumstances. Luckily these standards improved again in 2021. The positive COVID19 status itself did not have a direct impact on mortality. Strikingly, none of the 33 surgically treated COVID positive patients during both years died postoperatively. This is an interesting fnding which, if confrmed through future research with a larger sample size of COVID19 positive patients, can expedite the recovery phase of acute surgical service

Noncoding RNA Mediated Traffic of Foreign mRNA into Chloroplasts Reveals a Novel Signaling Mechanism in Plants

Communication between chloroplasts and the nucleus is one of the milestones of the evolution of plants on earth. Proteins encoded by ancestral chloroplast-endogenous genes were transferred to the nucleus during the endosymbiotic evolution and originated this communication, which is mainly dependent on specific transit-peptides. However, the identification of nuclear-encoded proteins targeted to the chloroplast lacking these canonical signals suggests the existence of an alternative cellular pathway tuning this metabolic crosstalk. Non-coding RNAS (NcRNAs) are increasingly recognized as regulators of gene expression as they play roles previously believed to correspond to proteins. Avsunviroidae family viroids are the only noncoding functional RNAs that have been reported to traffic inside the chloroplasts. Elucidating mechanisms used by these pathogens to enter this organelle will unearth novel transport pathways in plant cells. Here we show that a viroid-derived NcRNA acting as a 5′UTR-end mediates the functional import of Green Fluorescent Protein (GFP) mRNA into chloroplast. This claim is supported by the observation at confocal microscopy of a selective accumulation of GFP in the chloroplast of the leaves expressing the chimeric vd-5′UTR/GFP and by the detection of the GFP mRNA in chloroplasts isolated from cells expressing this construct. These results support the existence of an alternative signaling mechanism in plants between the host cell and chloroplasts, where an ncRNA functions as a key regulatory molecule to control the accumulation of nuclear-encoded proteins in this organelle. In addition, our findings provide a conceptual framework to develop new biotechnological tools in systems using plant chloroplast as bioreactors. Finally, viroids of the family Avsunviroidae have probably evolved to subvert this signaling mechanism to regulate their differential traffic into the chloroplast of infected cells

A Manifesto for Plant Science Education

Societal Impact Statement Plants provide oxygen, food, shelter, medicines, and environmental services, without which human society could not exist. Tackling pressing and global challenges requires well-trained plant scientists and plant-aware individuals. This manifesto provides a practical evidence-based vision to strengthen plant science education, focussed on five strategic priorities. It is relevant to all stakeholders within plant science and beyond: from frontline educators to institutional leaders; from commercial or charitable professionals to entrepreneurs and donors; from individual community members to their legislative representatives. Strengthening plant science education demands concrete actions from all stakeholders, ultimately to the benefit of us all. Summary Plant science education needs urgent attention. Skilled plant scientists are needed to address major environmental and societal challenges, and global communities require plant-aware professionals to drive impactful policy, research and environmental stewardship. This manifesto was collaboratively generated by a community of educators who gathered to reflect on the state of plant science education. The forward-facing document provides a clear strategy for plant science education, complementing existing research strategies. Five themes were identified as essential for meeting the evolving needs of plant science, educators and learners: (i) plants must be at the centre of an education that addresses global challenges and societal values; (ii) plant science education must prepare students for their futures using bold and effective pedagogies (iii) equity, diversity and inclusion must be robustly embedded in educational practices; (iv) local and strategic partnerships (with industry and beyond) are required to strengthen academic education; and (v) plant science educators need resources and opportunities to develop and connect. The manifesto is intended as a framework for change. Educators, funders, publishers, industry representatives, policymakers, and all other members of our communities, must commit to sustained investment in plant science education. By proactively and collectively embracing the recommendations provided, the sector has an opportunity to cultivate a new generation equipped with the knowledge, skills, and passion to unlock the full potential of photosynthetic organisms. <br/

A manifesto for plant science education

Societal Impact Statement Plants provide oxygen, food, shelter, medicines and environmental services, without which human society could not exist. Tackling pressing and global challenges requires well-trained plant scientists and plant-aware individuals. This manifesto provides a practical evidence-based vision to strengthen plant science education, focused on five strategic priorities. It is relevant to all stakeholders within plant science and beyond: from frontline educators to institutional leaders; from commercial or charitable professionals to entrepreneurs and donors; from individual community members to their legislative representatives. Strengthening plant science education demands concrete actions from all stakeholders, ultimately to the benefit of us all. Summary Plant science education needs urgent attention. Skilled plant scientists are needed to address major environmental and societal challenges, and global communities require plant-aware professionals to drive impactful policy, research and environmental stewardship. This manifesto was collaboratively generated by a community of educators who gathered to reflect on the state of plant science education. The forward-facing document provides a clear strategy for plant science education, complementing existing research strategies. Five themes were identified as essential for meeting the evolving needs of plant science, educators and learners: (i) plants must be at the centre of an education that addresses global challenges and societal values; (ii) plant science education must prepare students for their futures using bold and effective pedagogies; (iii) equity, diversity and inclusion must be robustly embedded in educational practices; (iv) local and strategic partnerships (with industry and beyond) are required to strengthen academic education; and (v) plant science educators need resources and opportunities to develop and connect. The manifesto is intended as a framework for change. Educators, funders, publishers, industry representatives, policymakers and all other members of our communities must commit to sustained investment in plant science education. By proactively and collectively embracing the recommendations provided, the sector has an opportunity to cultivate a new generation equipped with the knowledge, skills and passion to unlock the full potential of photosynthetic organisms

Mutations in the chloroplast inner envelope protein TIC100 impair and repair chloroplast protein import and impact retrograde signalling

Chloroplast biogenesis requires synthesis of proteins in the nucleocytoplasm and the chloroplast itself. Nucleus-encoded chloroplast proteins are imported via multiprotein translocons in the organelle’s envelope membranes. Controversy exists around whether a 1 MDa complex comprising TIC20, TIC100 and other proteins constitutes the inner membrane TIC translocon. The Arabidopsis cue8 virescent mutant is broadly defective in plastid development. We identify CUE8 as TIC100. The tic100cue8 mutant accumulates reduced levels of 1 MDa complex components and exhibits reduced import of two nucleus-encoded chloroplast proteins of different import profiles. A search for suppressors of tic100cue8 identified a second mutation within the same gene, tic100soh1, which rescues the visible, 1 MDa complex-subunit abundance, and chloroplast protein import phenotypes. tic100soh1 retains but rapidly exits virescence, and rescues the synthetic lethality of tic100cue8 when retrograde signalling is impaired by the gun1 mutation. Alongside the strong virescence, changes in RNA editing and the presence of unimported precursor proteins show that a strong signalling response is triggered when TIC100 function is altered. Our results are consistent with a role for TIC100, and by extension the 1 MDa complex, in the chloroplast import of photosynthetic and non-photosynthetic proteins, a process which initiates retrograde signalling

A role for SENSITIVE TO FREEZING2 in protecting chloroplasts against freeze-induced damage in Arabidopsis.

SUMMARY: The sensitive to freezing2 (SFR2) gene has an important role in freezing tolerance in Arabidopsis thaliana. We show that homologous genes are present, and expressed, in a wide range of terrestrial plants, including species not able to tolerate freezing. Expression constructs derived from the cDNAs of a number of different plant species, including examples not tolerant to freezing, are able to complement the freezing sensitivity of the Arabidopsis sfr2 mutant. In Arabidopsis the SFR2 protein is localized to the chloroplast outer envelope membrane, as revealed by the analysis of transgenic plants expressing SFR2 fusions to GFP, by confocal microscopy, and by the immunological analysis of isolated chloroplasts treated with thermolysin protease. Moreover, the chloroplasts of the sfr2 mutant show clear evidence of rapid damage after a freezing episode, suggesting a role for SFR2 in the protection of the chloroplast