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Green plants (Viridiplantae) include around 450,000-500,000 species1,2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life.

C2 photosynthesis is a photosynthetic pathway in which photorespiratory CO2 release and refixation are enhanced in leaf bundle sheath (BS) tissues. The evolution of C2 photosynthesis has been hypothesized to be a major step in the origin of C4 photosynthesis, highlighting the importance of studying C2 evolution. In this study, physiological, anatomical, ultrastructural, and immunohistochemical properties of leaf photosynthetic tissues were investigated in six non‐C4Tribulus species and four C4Tribulus species. At 42°C, T. cristatus exhibited a photosynthetic CO2 compensation point in the absence of respiration (C*) of 21 µmol mol−1, below the C3 mean C* of 73 µmol mol−1. Tribulus astrocarpus had a C* value at 42°C of 55 µmol mol−1, intermediate between the C3 species and the C2T. cristatus. Glycine decarboxylase (GDC) allocation to BS tissues was associated with lower C*. Tribulus cristatus and T. astrocarpus allocated 86% and 30% of their GDC to the BS tissues, respectively, well above the C3 mean of 11%. Tribulus astrocarpus thus exhibits a weaker C2 (termed sub‐C2) phenotype. Increased allocation of mitochondria to the BS and decreased length‐to‐width ratios of BS cells, were present in non‐C4 species, indicating a potential role in C2 and C4 evolution. Summary statement: Physiological, structural, and immunohistochemical analyses of leaf tissues indicate sub‐C2 and C2 character states occurring in Tribulus (Zygophyllaceae). These data reveal novel insights into the mechanisms by which photorespiratory CO2 refixation facilitates the evolution of C4 photosynthesis. [ABSTRACT FROM AUTHOR]

Assessment is a central component of course curriculums and is used to certify student learning, but it can also be used as a tool to improve teaching and learning. Many laboratory courses are structured such that there is only a grade for a particular laboratory, which limits the insights that can be gained in student learning. We developed a laboratory program that incorporates assessments designed to probe student understanding of different components of the individual modules making up the program. The challenge was to analyze and present grades from these assessment tasks in a format that was readily interpretable by academics. We show that a simplified synthesis of grade distributions (grade distribution digests) provides sufficient information to make decisions about changes in course components. The main feature of the digests is its data visualization approach, where student grades for individual laboratory practicals, individual assessment tasks or individual assessment items are graphically presented as an overall average grade, an average top quartile grade and an average bottom quartile grade, and relative averages across all assessments. This ability to visualize student grades in variety of contexts enables academics with many other demands on their time (e.g. research and administration) to more efficiently identify ways to improve teaching delivery and learning outcomes. Examples are presented of the use of such data to identify and improve deficiencies in both student skills and teaching practice, resulting in improved learning outcomes.

A new laboratory practical system is described which is comprised of a number of laboratory practical modules, each based around a particular technique or set of techniques, related to the theory part of the course but not designed to be dependent on it. Each module comprises an online recorded pre-lab lecture, the laboratory practical itself and a post-lab session in which students make oral presentations on different aspects of the practical. Each part of the module is assessed with the aim of providing rapid feedback to staff and students. Each laboratory practical is the responsibility of a single staff member and through this "ownership," continual review and updating is promoted. Examples of changes made by staff to modules as a result of student feedback are detailed. A survey of students who had experienced both the old-style laboratory course and the new one provided evidence of increased satisfaction with the new program. The assessment of acquired shills in the new program showed that it was much more effective than the old course.

The structures of the Ala177Val mutant of E. coli methylenetetrahydrofolate (MTHFR) and of its complex with the 5,10-dideazafolate analogue, LY309887 are reported the mechanisms by which the mutation may perturb FAD binding is suggested. In both human and E. coli MTHFR, the A- V mutation enhances the rate of dissociation of FAD, and in both enzymes loss of FAD is linked to changes in quaternary structure (2,19).