Stamen-derived bioactive gibberellin is essential for male flower development of Cucurbita maxima L.

Gibberellin (GA) signalling during pumpkin male flower development is highly regulated, including biosynthetic, perception, and transduction pathways. GA 20-oxidases, 3-oxidases, and 2-oxidases catalyse the final part of GA synthesis. Additionally, 7-oxidase initiates this part of the pathway in some cucurbits including Cucurbita maxima L. (pumpkin). Expression patterns for these GA-oxidase-encoding genes were examined by competitive reverse transcription-PCR (RT-PCR) and endogenous GA levels were determined during pumpkin male flower development. In young flowers, GA20ox3 transcript levels are high in stamens, followed by high levels of the GA precursor GA9. Later, just before flower opening, transcript levels for GA3ox3 and GA3ox4 increase in the hypanthium and stamens, respectively. In the stamen, following GA3ox4 expression, bioactive GA4 levels rise dramatically. Accordingly, catabolic GA2ox2 and GA2ox3 transcript levels are low in developing flowers, and increase in mature flowers. Putative GA receptor GID1b and DELLA repressor GAIPb transcript levels do not change in developing flowers, but increase sharply in mature flowers. Emasculation arrests floral development completely and leads to abscission of premature flowers. Application of GA4 (but not of its precursors GA12-aldehyde or GA9) restores normal growth of emasculated flowers. These results indicate that de novo GA4 synthesis in the stamen is under control of GA20ox3 and GA3ox4 genes just before the rapid flower growth phase. Stamen-derived bioactive GA is essential and sufficient for male flower development, including the petal and the pedicel growth

Using data science for sustainable development in higher education

Despite the abundance of studies focused on how higher education institutions (HEIs) are implementing sustainable development (SD) in their educational programmes, there is a paucity of interdisciplinary studies exploring the role of technology, such as data science, in an SD context. Further research is thus needed to identify how SD is being deployed in higher education (HE), generating positive externalities for society and the environment. This study aims to address this research gap by exploring various ways in which data science may support university efforts towards SD. The methodology relied on a bibliometric analysis to understand and visualise the connections between data science and SD in HE, as well as reporting on selected case studies showing how data science may be deployed for creating SD impact in HE and in the community. The results from the bibliometric analysis unveil five research strands driving this field, and the case studies exemplify them. This study can be considered innovative since it follows previous research on artificial intelligence and SD. Moreover, the combination of bibliometric analysis and case studies provides an overview of trends, which may be useful to researchers and decision-makers who wish to explore the use of data science for SD in HEIs. Finally, the findings highlight how data science can be used in HEIs, combined with a framework developed to support further research into SD in HE

Expression Studies of Gibberellin Oxidases in Developing Pumpkin Seeds

Two cDNA clones, 3-ox and 2-ox, have been isolated from developing pumpkin (Cucurbita maxima) embryos that show significant amino acid homology to gibberellin (GA) 3-oxidases and 2-oxidases, respectively. Recombinant fusion protein of clone 3-ox converted GA(12)-aldehyde, GA(12), GA(15), GA(24), GA(25), and GA(9) to GA(14)-aldehyde, GA(14), GA(37), GA(36), GA(13), and GA(4), respectively. Recombinant 2-ox protein oxidized GA(9), GA(4), and GA(1) to GA(51), GA(34), and GA(8), respectively. Previously cloned GA 7-oxidase revealed additional 3β-hydroxylation activity of GA(12). Transcripts of this gene were identified in endosperm and embryo of the developing seed by quantitative reverse transcriptase-polymerase chain reaction and localized in protoderm, root apical meristem, and quiescent center by in situ hybridization. mRNA of the previously cloned GA 20-oxidase from pumpkin seeds was localized in endosperm and in tissues of protoderm, ground meristem, and cotyledons of the embryo. However, transcripts of the recently cloned GA 20-oxidase from pumpkin seedlings were found all over the embryo, and in tissues of the inner seed coat at the micropylar end. Previously cloned GA 2β,3β-hydroxylase mRNA molecules were specifically identified in endosperm tissue. Finally, mRNA molecules of the 3-ox and 2-ox genes were found in the embryo only. 3-ox transcripts were localized in tissues of cotyledons, protoderm, and inner cell layers of the root apical meristem, and 2-ox transcripts were found in all tissues of the embryo except the root tips. These results indicate tissue-specific GA-biosynthetic pathways operating within the developing seed

Gibberellin Biosynthesis in Developing Pumpkin Seedlings

A gibberellin (GA) biosynthetic pathway was discovered operating in root tips of 7-d-old pumpkin (Cucurbita maxima) seedlings. Stepwise analysis of GA metabolism in cell-free systems revealed the conversion of GA(12)-aldehyde to bioactive GA(4) and inactive GA(34). Highest levels of endogenous GA(4) and GA(34) were found in hypocotyls and root tips of 3-d-old seedlings. cDNA molecules encoding two GA oxidases, CmGA20ox3 and CmGA3ox3, were isolated from root tips of 7-d-old LAB150978-treated seedlings. Recombinant CmGA20ox3 fusion protein converted GA(12) to GA(9), GA(24) to GA(9), GA(14) to GA(4), and, less efficiently, GA(53) to GA(20), and recombinant CmGA3ox3 protein oxidized GA(9) to GA(4). Transcript profiles were determined for four GA oxidase genes from pumpkin revealing relatively high transcript levels for CmGA7ox in shoot tips and cotyledons, for CmGA20ox3 in shoot tips and hypocotyls, and for CmGA3ox3 in hypocotyls and roots of 3-d-old seedlings. Transcripts of CmGA2ox1 were mainly found in roots of 7-d-old seedlings. In roots of 7-d-old seedlings, transcripts of CmGA7ox, CmGA20ox3, and CmGA3ox3 were localized in the cap and the rhizodermis by in situ hybridization. We conclude that hypocotyls and root tips are important sites of GA biosynthesis in the developing pumpkin seedling

Root-derived GA12_{12} contributes to temperature-induced shoot growth in ArabidopsisArabidopsis

International audiencePlants are able to sense a rise in temperature of several degrees, and appropriately adapt their metabolic and growth processes. To this end, plants produce various signalling molecules that act throughout the plant body. Here, we report that root-derived GA$_{12}$, a precursor of the bioactive gibberellins, mediates thermo-responsive shoot growth in $Arabidopsis$. Our data suggest that root-to-shoot translocation of GA$_{12}$ enables a flexible growth response to ambient temperature changes

Barriers to Institutional Social Sustainability

Social sustainability is a work field characterised by an emphasis on social aspects, e.g. equity, ethics, health, gender balance, or empowerment, within a broader sustainability context. Although the concept seems to be reasonably well established and deemed worthy of pursuing, some obstacles prevent its wide dissemination. Through a bibliometric analysis focusing on the literature on social sustainability at institutions, with a focus on companies, this paper aims to investigate and describe some of the barriers associated with social sustainability implementation. Apart from identifying that sustainability reporting, environmental disclosure and financial performance play a central role in successfully achieving social sustainability, in the context of which gender-related issues seem more tangential, the results indicated some solutions commonly reported for overcoming barriers and obstacles to a company’s social sustainability implementation within different sectors. These solutions have to do, among many other factors addressed in this study, with strengthening communication transparency and trust, contributing to awareness, using technology to document and promote social sustainability. Thus, empowering organizations and citizens, recognized as essential factors to social development, and addressing the challenges in a multi-dimensional way