Search for: All records

Synopsis Plants are fundamental to life, providing oxygen, food, and climate regulation, while also offering solutions to global challenges. Integrating plant biology into an undergraduate curriculum, while supporting and nurturing students’ career interests present both opportunities and challenges. Undergraduate biology education often overlooks plants due to limited student interest and a strong focus on health professions, particularly among women and underrepresented minorities. Here, we describe how plants are incorporated in the Biology curriculum at Spelman College, a women’s liberal arts college and a Historically Black College and University where Biology is a popular major. The department has successfully embedded plant biology across its skills and competency-based curriculum, from the foundational introductory sequence to upper-level electives and research experiences. Students learn core biological concepts in the introductory core curriculum, consisting of four courses progressing from ecological to molecular levels, where plant-related content is integrated through inquiry driven, hands-on activities or field trips. In upper-level electives and research-based courses, faculty offer a robust program in plant biology that enables deeper understanding and integration across disciplines as they address real world problems that intersect with students’ diverse interests. Survey data indicate that students perceive a balanced exposure to plants and other organisms in introductory courses and recognize the importance of plants for understanding core biological principles. Although this exposure does not significantly shift their primary career interest in medicine, it contributes to a broad biology education, skill development, and an increased interest in research. 

Abstract Allostery is a hallmark of cellular function and important in every biological system. Still, we are only starting to mimic it in the laboratory. Here, we introduce an approach to study aspects of allostery in artificial systems. We use a DNA origami domino array structure which–upon binding of trigger DNA strands–undergoes a stepwise allosteric conformational change. Using two FRET probes placed at specific positions in the DNA origami, we zoom in into single steps of this reaction cascade. Most of the steps are strongly coupled temporally and occur simultaneously. Introduction of activation energy barriers between different intermediate states alters this coupling and induces a time delay. We then apply these approaches to release a cargo DNA strand at a predefined step in the reaction cascade to demonstrate the applicability of this concept in tunable cascades of mechanochemical coupling with both spatial and temporal control. 

Abstract Background Nuclear endosperm development is a common mechanism among Angiosperms, including Arabidopsis. During nuclear development, the endosperm nuclei divide rapidly after fertilization without cytokinesis to enter the syncytial phase, which is then followed by the cellularized phase. The endosperm can be divided into three spatial domains with distinct functions: the micropylar, peripheral, and chalazal domains. Previously, we identified two putative small invertase inhibitors, InvINH1 and InvINH2, that are specifically expressed in the micropylar region of the syncytial endosperm. In addition, ectopically expressing InvINH1 in the cellularized endosperm led to a reduction in embryo growth rate. However, it is not clear what are the upstream regulators responsible for the specific expression of InvINHs in the syncytial endosperm. Results Using protoplast transient expression system, we discovered that a group of type I MADS box transcription factors can form dimers to activate InvINH1 promoter. Promoter deletion assays carried out in the protoplast system revealed the presence of an enhancer region in InvINH1 promoter, which contains several consensus cis-elements for the MADS box proteins. Using promoter deletion assay in planta , we further demonstrated that this enhancer region is required for InvINH1 expression in the syncytial endosperm. One of the MADS box genes, AGL62, is a key transcription factor required for syncytial endosperm development. Using promoter-GFP reporter assay, we demonstrated that InvINH1 and InvINH2 are not expressed in agl62 mutant seeds. Collectively, our data supports the role of AGL62 and other type I MADS box genes as the upstream activators of InvINHs expression in the syncytial endosperm. Conclusions Our findings revealed several type I MADS box genes that are responsible for activating InvINH1 in the syncytial endosperm, which in turn regulates embryo growth rate during early stage of seed development.