This encyclopedia focuses on the key concepts, debates, approaches and schools of thought on higher education, and brings together the best thinking about the role of universities.
In plants, asymmetric cell divisions result in distinct cell fates forming large and small daughter cells, adding to the cellular diversity in an organ. SCARECROW (SCR), a GRAS domain-containing ...transcription factor controls asymmetric periclinal cell divisions in flowering plants by governing radial patterning of ground tissue in roots and cell proliferation in leaves. Though SCR homologs are present across land plant lineages, the current understanding of their role in cellular patterning and leaf development is mostly limited to flowering plants. Our phylogenetic analysis identified three SCR homologs in moss
Physcomitrium patens
, amongst which
PpSCR1
showed highest expression in gametophores and its promoter activity was prominent at the mid-vein and the flanking leaf blade cells pointing towards its role in leaf development. Notably, out of the three SCR homologs, only the
ppscr1
knock-out lines developed slender leaves with four times narrower leaf blade and three times thicker mid-vein. Detailed histology studies revealed that slender leaf phenotype is either due to the loss of anticlinal cell divisions or failure of periclinal division suppression in the leaf blade. RNA-Seq analyses revealed that genes responsible for cell division and differentiation are expressed differentially in the mutant. PpSCR1 overexpression lines exhibited significantly wider leaf lamina, further reconfirming the role in leaf development. Together, our data suggests that PpSCR1 is involved in the leaf blade and mid-vein development of moss and that its role in the regulation of cell division and proliferation is ancient and conserved among flowering plants and mosses.
Key message
The GRAS domain containing protein PpSCR1 regulates asymmetric cell divisions and governs leaf blade and mid-vein development in moss
Physcomitrium patens.
Key message
We demonstrate a new regulatory mechanism in the jasmonic acid (JA) and salicylic acid (SA) mediated crosstalk in potato defense response, wherein, miR160 target
StARF16
(a gene involved ...in growth and development) binds to the promoter of
StNPR1
(a defense gene) and negatively regulates its expression to suppress the SA pathway. Overall, our study establishes the importance of StARF16 in regulation of
StNPR1
during JA mediated defense response upon necrotrophic pathogen interaction.
Plants employ antagonistic crosstalk between salicylic acid (SA) and jasmonic acid (JA) to effectively defend them from pathogens. During biotrophic pathogen attack, SA pathway activates and suppresses the JA pathway via NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1). However, upon necrotrophic pathogen attack, how JA-mediated defense response suppresses the SA pathway, is still not well-understood. Recently
StARF10
(
AUXIN RESPONSE FACTOR
), a miR160 target, has been shown to regulate SA and binds to the promoter of
StGH3
.6 (
GRETCHEN HAGEN3
), a gene proposed to maintain the balance between the free SA and auxin in plants. In the current study, we investigated the role of
StARF16
(a miR160 target) in the regulation of the defense gene
StNPR1
in potato upon activation of the JA pathway. We observed that a negative correlation exists between
StNPR1
and
StARF16
upon infection with the pathogen. The results were further confirmed through the exogenous application of SA and JA. Using yeast one-hybrid assay, we demonstrated that StARF16 binds to the
StNPR1
promoter through putative ARF binding sites. Additionally, through protoplast transfection and chromatin immunoprecipitation experiments, we showed that StARF16 could bind to the
StNPR1
promoter and regulate its expression. Co-transfection assays using promoter deletion constructs established that ARF binding sites are present in the 2.6 kb sequence upstream to the
StNPR1
gene and play a key role in its regulation during infection. In summary, we demonstrate the importance of
StARF16
in the regulation of
StNPR1
, and thus SA pathway, during JA-mediated defense response upon necrotrophic pathogen interaction.
Convergent evolution of shoot development across plant lineages has prompted numerous comparative genetic studies. Though functional conservation of gene networks governing flowering plant shoot ...development has been explored in bryophyte gametophore development, the role of bryophyte-specific genes remains unknown. Previously, we have reported Tnt1 insertional mutants of moss defective in gametophore development. Here, we report a mutant (short-leaf; shlf) having two-fold shorter leaves, reduced apical dominance, and low plasmodesmata frequency. UHPLC-MS/MS-based auxin quantification and analysis of soybean (Glycine max) auxin-responsive promoter (GH3:GUS) lines exhibited a striking differential auxin distribution pattern in the mutant gametophore. Whole-genome sequencing and functional characterization of candidate genes revealed that a novel bryophyte-specific gene (SHORT-LEAF; SHLF) is responsible for the shlf phenotype. SHLF represents a unique family of near-perfect tandem direct repeat (TDR)-containing proteins conserved only among mosses and liverworts, as evident from our phylogenetic analysis. Cross-complementation with a Marchantia homolog partially recovered the shlf phenotype, indicating possible functional specialization. The distinctive structure (longest known TDRs), absence of any known conserved domain, localization in the endoplasmic reticulum, and proteolytic cleavage pattern of SHLF imply its function in bryophyte-specific cellular mechanisms. This makes SHLF a potential candidate to study gametophore development and evolutionary adaptations of early land plants.
Chitin, a crucial structural and functional component of insects and fungi, serves as a target for pest management by utilizing novel chitinases. Here, we report the biocontrol potential of ...recombinant Myrothecium verrucaria endochitinase (rMvEChi) against insect pest and fungal pathogens. A complete ORF of MvEChi (1185 bp) was cloned and heterologously expressed in Escherichia coli. Structure based sequence alignment of MvEChi revealed the presence of conserved domains SXGG and DXXDXDXE specific for GH-18 family, involved in substrate binding and catalysis, respectively. rMvEChi (46.6 kDa) showed optimum pH and temperature as 7.0 and 30 °C, respectively. Furthermore, rMvEChi remained stable within the pH range of 6.0 to 8.0 and up to 40 °C. rMvEChi exhibited kcat/Km values of 129.83 × 103 (g/L)−1 s−1 towards 4MU chitotrioside. Hydrolysis of chitooligosaccharides with various degrees of polymerization (DP) using rMvEChi indicated the release of DP2 as main end product with order of reaction as DP6 > DP5 > DP4 > DP3. Bioassay of rMvEChi against Helicoverpa armigera displayed potent anti-feedant activity and induced mortality. In vitro antifungal activity against plant pathogenic fungi (Ustilago maydis and Bipolaris sorokiniana) exhibited significant inhibition of mycelium growth. These results suggest that MvEChi has significant potential in enzyme-based pest and pathogen management.
Earth observation (EO) data can provide large scale, high-resolution, and transferable methodologies to quantify the sprawl and vertical development of cities and are required to inform disaster risk ...reduction strategies for current and future populations. We synthesize the evolution of Bishkek, Kyrgyzstan, which experiences high seismic hazard, and derive new datasets relevant for seismic risk modeling. First, the urban sprawl of Bishkek (1979–2021) was quantified using built-up area land cover classifications. Second, a change detection methodology was applied to a declassified KeyHole Hexagon (KH-9) and Sentinel-2 satellite image to detect areas of redevelopment within Bishkek. Finally, vertical development was quantified using multi-temporal high-resolution stereo and tri-stereo satellite imagery, which were used in a deep learning workflow to extract buildings footprints and assign building heights. Our results revealed urban growth of 139 km2 (92%) and redevelopment of ~26% (59 km2) of the city (1979–2021). The trends of urban growth were not reflected in all the open access global settlement footprint products that were evaluated. Building polygons that were extracted using a deep learning workflow applied to high-resolution tri-stereo (Pleiades) satellite imagery were most accurate (F1 score = 0.70) compared to stereo (WorldView-2) imagery (F1 score = 0.61). Similarly, building heights extracted using a Pleiades-derived digital elevation model were most comparable to independent measurements obtained using ICESat-2 altimetry data and field-measurements (normalized absolute median deviation < 1 m). Across different areas of the city, our analysis suggested rates of building growth in the region of 2000–10,700 buildings per year, which when combined with a trend of urban growth towards active faults highlights the importance of up-to-date building stock exposure data in areas of seismic hazard. Deep learning methodologies applied to high-resolution imagery are a valuable monitoring tool for building stock, especially where country-level or open-source datasets are lacking or incomplete.
A novel series of 1,4-bis(6-(substituted phenyl)-1,2,4-triazolo3,4-
b-1,3,4-thiadiazoles (
5a–
b) and 4-bis(substituted phenyl)-4-thiazolidinone derivatives (
7a–
c) have been synthesized from ...terephthalic dihydrazide (
1) through multistep reaction sequence. 1,4-Bis(5-aryl-1,3,4-oxadiazole-2yl) benzene derivatives (
2a–
f) and bis-substituted terephthalohydrazide (
6a–
e) were also synthesized from terephthalic dihydrazide by cyclization with various aromatic acids and aldehydes. Terephthalic dihydrazide (
1) was obtained from poly(ethylene terephthalate) waste from reaction with hydrazine hydrate in good yield (86%). All the synthesized compounds were screened for their antibacterial activities against various bacteria and fungi strains. Several of these compounds showed potential antibacterial activity.
A novel series of 1,4-bis(6-(substituted phenyl)-1,2,4-triazolo3,4-
b-1,3,4-thiadiazoles and 4-bis(substituted phenyl)-4-thiazolidinone derivatives have been synthesized from terephthalic dihydrazide through multistep reaction sequence. 1,4-Bis(5-aryl-1,3,4-oxadiazole-2yl) benzene derivatives and bis-substituted terephthalo-hydrazides were also synthesized.
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Many earthquake properties, including slip, show self‐similar (fractal) features. We can incorporate self‐similarity into Bayesian slip inversions via von Karman correlation, so that the ...regularization applied is representative of observed fault features. In von Karman regularization, each slip patch has a relationship to every other patch. This means that von Karman regularization only has meaning when applied to patches that actually slipped; if applied to nonslipping patches, spurious slip can be added to meet the von Karman correlation criteria. Additionally, the fault size, usually chosen in advance, also affects the von Karman correlation lengths meaning that the final slip solution may be biased by initial geometry choices. Here we present a method for solving for the size of the fault plane during the slip inversion process, as well as slip, rake, and a hyperparameter controlling slip variance. We use a transdimensional Bayesian inversion scheme constrained by geodetic surface displacements and regularized using von Karman correlation. We use circular harmonics to solve for the size of the slipping area, to allow for a complex shape that is connected and continuous across the fault. We apply this method to the 2016 Mw 6.2 Central Tottori earthquake, Japan, constrained by interferometric synthetic aperture radar InSAR (Sentinel‐1 and ALOS‐2) and Global Navigation Satellite System data (GNSS). We find an area of slip extending from approximately 2‐ to 10‐km depth, with the slipping area elongated in the downdip direction. In contrast to some seismic studies, we find slip ruptured most of the seismogenic layer.
Key Points
We incorporate von Karman regularization into geodetic Bayesian slip inversions to capture the fractal nature of slip
We also solve for fault size using a transdimensional Bayesian inversion to remove bias caused by fault size in von Karman regularization
Application to the 2016 Tottori, Japan, earthquake shows that contrary to some seismic studies, slip ruptured almost to the surface
The ATP-binding cassette transporter A1 (ABCA1) facilitates cholesterol efflux from cells, a key process in reverse cholesterol transport. Whereas previous investigations focused on mutations causing ...impaired ABCA1 function, we assessed the role of ABCA1 in human carotid atherosclerotic disease.
We compared the mRNA and protein levels of ABCA1, and one of its key regulators, the liver X receptor alpha (LXRalpha), between minimally and grossly atherosclerotic arterial tissue. We established ABCA1 and LXRalpha gene expression by real-time quantitative polymerase chain reaction in 10 control and 18 atherosclerotic specimens. Presence of ABCA1 protein was assessed by immunoblotting. To determine whether differences observed at a local level were reflected in the systemic circulation, we measured ABCA1 mRNA in leukocytes of 10 patients undergoing carotid endarterectomy and 10 controls without phenotypic atherosclerosis.
ABCA1 and LXRalpha gene expression were significantly elevated in atherosclerotic plaques (P<0.0001 and 0.03, respectively). The increased mRNA levels of ABCA1 and LXRalpha were correlated in atherosclerotic tissue (r=0.85; P<0.0001). ABCA1 protein expression was significantly reduced in plaques compared with control tissues (P<0.0001). There were no differences in leukocyte ABCA1 mRNA expression (P=0.67).
ABCA1 gene and protein are expressed in minimally atherosclerotic human arteries. Despite significant upregulation of ABCA1 mRNA, possibly mediated via LXRalpha, ABCA1 protein is markedly reduced in advanced carotid atherosclerotic lesions. No differences in leukocyte ABCA1 expression were found, suggesting the plaque microenvironment may contribute to the differential ABCA1 expression. We propose that the decreased level of ABCA1 protein is a key factor in the development of atherosclerotic lesions.
In 2016, 10 universities launched a Networked Improvement Community (NIC) aimed at increasing the number of scholars from Alliances for Graduate Education and the Professoriate (AGEP) populations ...entering science, technology, engineering, and mathematics (STEM) faculty careers. NICs bring together stakeholders focused on a common goal to accelerate innovation through structured, ongoing intervention development, implementation, and refinement. We theorized a NIC organizational structure would aid understandings of a complex problem in different contexts and accelerate opportunities to develop and improve interventions to address the problem. A distinctive feature of this NIC is its diverse institutional composition of public and private, predominantly white institutions, a historically Black university, a Hispanic-serving institution, and land grant institutions located across eight states and Washington, DC, United States. NIC members hold different positions within their institutions and have access to varied levers of change. Among the many lessons learned through this community case study, analyzing and addressing failed strategies is as equally important to a healthy NIC as is sharing learning from successful interventions. We initially relied on pre-existing relationships and assumptions about how we would work together, rather than making explicit how the NIC would develop, establish norms, understand common processes, and manage changing relationships. We had varied understandings of the depth of campus differences, sometimes resulting in frustrations about the disparate progress on goals. NIC structures require significant engagement with the group, often more intensive than traditional multi-institution organizational structures. They require time to develop and ongoing maintenance in order to advance the work. We continue to reevaluate our model for leadership, climate, diversity, conflict resolution, engagement, decision-making, roles, and data, leading to increased investment in the success of all NIC institutions. Our NIC has evolved from the traditional NIC model to become the Center for the Integration of Research, Teaching and Learning (CIRTL) AGEP NIC model with five key characteristics: (1) A well-specified aim, (2) An understanding of systems, including a variety of contexts and different organizations, (3) A culture and practice of shared leadership and inclusivity, (4) The use of data reflecting different institutional contexts, and (5) The ability to accelerate infrastructure and interventions. We conclude with recommendations for those considering developing a NIC to promote diversity, equity, and inclusion efforts.
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