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Pentatricopeptide repeat (PPR) proteins form a large protein family in land plants, with hundreds of different members in angiosperms. In the last decade, a number of studies have shown that PPR proteins are sequence-specific RNA-binding proteins involved in multiple aspects of plant organellar RNA processing, and perform numerous functions in plants throughout their life cycle. Recently, computational and structural studies have provided new insights into the working mechanisms of PPR proteins in RNA recognition and cytidine deamination. In this review, we summarized the research progress on the functions of PPR proteins in plant growth and development, with a particular focus on their effects on cytoplasmic male sterility, stress responses, and seed development. We also documented the molecular mechanisms of PPR proteins in mediating RNA processing in plant mitochondria and chloroplasts.

This paper reports a qualitative study on the Chinese language learning trajectories of non-native Chinese instructors as successful Chinese language learners . While some literature has been found on studying good learners of English and other languages, there is a lack of research on studying good learners of the Chinese language, especially on their life-long Chinese learning process. Six active instructors teaching Chinese at K-12 schools or universities in the United States, whose native language is English, were interviewed on a one-on-one basis with an auto/biographical approach. This approach, as one type of narrative inquiries under a qualitative paradigm, has been increasingly used in the study of English language learners. Findings of the study include that the six participants all had experiences studying in Greater China, and all held lifelong learning attitude as well as demonstrated various self-regulation strategies with strong self-motivation and dedication. While they all took Chinese classes at college, only two of them studied prior to college, which is encouraging for Chinese learners who were unable to learn Chinese from an early age. This study helps to fill the gap in literature on good language learners of Chinese, and provides educational implications for Chinese language learners, instructors, researchers, and other stakeholders.

Key messageThe promoter of the Arabidopsis thaliana β-glucosidase 19 gene directs GUS expression in a seed-specific manner in transgenic Arabidopsis and tobacco.In the present study, an 898-bp putative promoter of the Arabidopsis β-glucosidase 19 (AtBGLU19) gene was cloned. The bioinformatics analysis of the cis-acting elements indicated that this putative promoter contains many seed-specific elements, such as RY elements. The features of this promoter fragment were evaluated for the capacity to direct the β-glucuronidase (GUS) reporter gene in transgenic Arabidopsis and tobacco. Histochemical and fluorometric GUS analyses of transgenic Arabidopsis plants revealed that the AtBGLU19 promoter directed strong GUS activity in late-maturing seeds and dry seeds, whereas no GUS expression was observed in other organs. The results indicated that the AtBGLU19 promoter was able to direct GUS expression in a seed-specific manner in transgenic Arabidopsis. In tobacco, the intensity of the staining and the level of GUS activity were considerably higher in the seeds than in the other tissues. These results further confirmed that the AtBGLU19 promoter is seed specific and can be used to control transgene expression in a heterologous plant system.

This article reports the findings of a case study that investigated the perceptions of international students regarding the impact of cultural differences on their learning experiences in an online MBA program. The study also revealed that online instructors need to design courses in such a way as to remove potential cultural barriers, including language, communication tool use, plagiarism, time zone differences and a lack of multicultural content, which may affect international students' learning performances. The study indicates that a culturally inclusive learning environment needs to consider diversity in course design in order to ensure full participation by international students.

Aggregation‐induced emission luminogens (AIEgens) have become a vital class of functional materials for optoelectronic and biomedical applications. Extending AIE behavior from single‐component to two‐component systems opens a new avenue for modulating emission through intermolecular interactions, yet it also introduces substantial complexity in understanding and controlling the aggregation process. In particular, elucidating how multicomponent molecular packing governs macroscopic photophysical behavior remains a central challenge. Herein, we constructed four distinct charge‐transfer (CT) cocrystals through the coassembly of electron‐rich dibenzo‐heterocyclic donors and electron‐deficient 1,2,4,5‐tetracyanobenzene (TCNB) acceptors. The cocrystallization process allows precise manipulation of the dynamic aggregation pathway by tuning the DMSO/H2O ratio. Intriguingly, the morphology evolves from amorphous aggregates to rod‐like and finally to needle‐like microcrystals, showing a nonmonotonic size variation with increasing water content, accompanied by a gradual enhancement of fluorescence intensity. The four CT complexes exhibit wide emission tunability from green to orange‐red, and notably, the AIE‐active DBT/TCNB pair enables a practical demonstration in water‐jet rewritable encryption paper. Overall, this work establishes a simple yet effective paradigm for designing high‐performance solid‐state emitters, while unveiling fundamental principles that govern the controllable molecular assembly in multicomponent luminescent systems. Charge‐transfer coassembly enables precise control over the dynamic aggregation process, resulting in morphology evolution from amorphous aggregates to rod‐like and needle‐like microcrystals, accompanied by a significant fluorescence enhancement. This strategy yields widely tunable solid‐state emission from green to orange‐red, unveiling fundamental principles governing controllable molecular assembly in multicomponent luminescent systems.

FUSCA3 (FUS3) is a member of the seed plant-specific B3 transcription factor family, a multifunctional plant regulator. In plants, the expression of the FUS3 gene is regulated mainly through transcriptional and post-transcriptional regulation, thereby giving it control over various functions. The transcription factor FUS3 can be involved in many important physiological processes in plants, such as transition of seed embryo developmental phase and accumulation of storage reserves during seed development. Recent studies have shown that FUS3 also regulates the development of plant lateral organs, activation of flowering sites, coordination of embryo and endosperm growth and helps plants resist heat stress. Therefore, it plays important roles in seed development and plant growth. Here, we provide an overview of FUS3, including the identification of the FUS3 gene, the regulation and functions of FUS3 and the functional mechanisms of FUS3. In addition, potential research directions are proposed that may shed new light on the functional mechanisms of FUS3 in plants.

Transcription factors are key molecules in the regulation of gene expression in all organisms. The transcription factor LEAFY COTYLEDON 2 (LEC2), which belongs to the DNA-binding protein family, contains a B3 domain. The transcription factor is involved in the regulation of important plant biological processes such as embryogenesis, somatic embryo formation, seed storage protein synthesis, fatty acid metabolism, and other important biological processes. Recent studies have shown that LEC2 regulates the formation of lateral roots and influences the embryonic resetting of the parental vernalization state. The orthologs of LEC2 and their regulatory effects have also been identified in some crops; however, their regulatory mechanism requires further investigation. Here, we summarize the most recent findings concerning the effects of LEC2 on plant growth and seed development. In addition, we discuss the potential molecular mechanisms of the action of the LEC2 gene during plant development.

Key message The bidirectional promoter of the Arabidopsis thaliana gene pair At1g71850/At1g71860 harbors low-temperature-responsive elements, which participate in anti-correlated transcription regulation of the driving genes in response to environmental low temperature. A divergent gene pair is defined as two adjacent genes organized head to head in opposite orientation, sharing a common promoter region. Divergent gene pairs are mainly coexpressed, but some display opposite regulation. The mechanistic basis of such anti-correlated regulation is not well understood. Here, the regulation of the Arabidopsis thaliana gene pair At1g71850/At1g71860 was investigated. Semi-quantitative RT-PCR and Genevestigator analyses showed that while one of the pair was upregulated by exposure to low temperature, the same treatment downregulated the other. Promoter:: GUS fusion transgenes were used to show that this behavior was driven by a bidirectional promoter, which harbored an as - 1 motif, associated with the low-temperature response; mutation of this sequence produced a significant decrease in cold-responsive expression. With regard to the as - 1 motif in the native orientation repressing the promoter’s low-temperature responsiveness, the same as - 1 motif introduced in the reverse direction showed a slight enhancement in the promoter’s responsiveness to low-temperature exposure, indicating that the orientation of the motif was important for the promoter’s activity. These findings provide new insights into the complex transcriptional regulation of bidirectional gene pairs as well as plant stress response.

PNZIP gene promoter has been cloned from Pharbitis nil by adaptor PCR, which conforms to eukaryotic promoter characteristic. Primer extension analysis showed that the transcription start site was located 122 nucleotides upstream of the translation start site of PNZIP gene. According to the characteristic of PNZIP promoter, a series of deletions were purposely made by PCR. Five deletion fragments were fused to upstream of GUS gene and transferred into tobacco. Fluorometric GUS assay showed that five different length promoters all could specifically drive GUS gene expression in photosynthetic tissues and their activities decreased along with the gradual deletion of PNZIP promoter. In addition, the activity of full-length promoter was 9 times higher than that of CaMV 35S in leaf. PNZIP promoter may have two putative cis-elements, GAAATA and GATACT, which relate to gene expression in photosynthetic tissues. GATACT may determine the gene specific expression in photosynthetic tissues, while GAAATA, perhaps, as an enhancer, increases the intensity of gene expression.

Online graduate courses and programs have grown exponentially in recent decades. As online graduate education expands, concerns arise regarding its quality. One critical element for course and program quality assurance is the assessment tasks used in individual courses. The impact of assessment tasks on teaching and learning is well recognized. Additionally, assessment tasks are argued to be more important in online environments than in traditional environments (e.g., Morgan & Reilly, 1999). While there is a plethora of literature on assessment tasks in traditional environments, there is a paucity of empirical research on assessment tasks in online environments. Furthermore, most of the available research studies on assessment in online environments were conducted in contexts other than graduate education. Considering the exponential growth of online graduate education, there is an urgent need to conduct more studies on assessment tasks in this context. This study was conducted in response to this need. Three overarching research questions guided this study: (1) What are current practices of online instructors in the use of assessment tasks in online graduate courses? (2) What are instructors’ rationales and what sources do they consult in the design and use of the assessment tasks? (3) How do they perceive key issues concerning the design and use of assessment tasks in online environments? To answer these questions, an exploratory qualitative approach was employed in this study. Participants were chosen from five different graduate programs that offered online courses at a Midwestern university in the United States. Twenty instructors participated in this study. Data collection methods included document analysis, virtual observation, and instructor interviews. Ten tendencies were identified from the 20 instructors' assessment practices. The assessment tasks used in the 22 online courses they taught were grouped into 21 categories. Seven main factors emerged from the rationales that instructors mentioned underlying the design of the assessment tasks. These factors included: (1) students, (2) motivation, (3) learning, (4) subject areas, (5) programs, (6) characteristics of the online delivery format, and (7) constraints. Subcategories under each of the categories were reported. Ten sources were identified from the instructors’ reflections on sources that they consulted in the design of online assessment tasks. Instructors’ perceptions on the similarities and differences between the use of assessment tasks in online and residential environments were reported. Their perceptions related to opportunities and challenges that online environments brought to assessment tasks were also noted. Findings of the study are discussed in light of the prevailing literature. Practical implications for instructors, instructional designers, administrators, and supporting staff are discussed. The dissertation ends with recommendations for future research.