Search

Problems with understanding concepts and mechanisms connected to plant movements have been diagnosed among biology students. Alternative conceptions in understanding these phenomena are marginally studied. The diagnosis was based on a sample survey of university students and their lecturers, which was quantitatively and qualitatively exploratory in nature (via a questionnaire). The research was performed in two stages, before and after the lectures and laboratory on plant movements. We diagnosed eight alternative conceptions before the academic training started. After the classes, most were not been verified, and in addition, 12 new conceptions were diagnosed. Additionally, we report that teachers are not aware of students' possible misunderstandings. They do not perceive students' troubles with switching between levels of representations, nor their alternative conceptions. A case of "curse of knowledge" was observed and academic teacher training is recommended. Additionally, the need for metacognition as a crucial element in laboratory activities seems supported by our presented results. Such metacognition refers to students as well as teachers, which leads to the conclusion that teachers should be aware of students' way of thinking and the development of knowledge in one's own mind.

Phytophthora species are oomycetes that have evolved a broad spectrum of biological processes and improved strategies to cope with host and environmental challenges. A growing body of evidence indicates that the high pathogen plasticity is based on epigenetic regulation of gene expression linked to Phytophthora's rapid adjustment to endogenous cues and various stresses. As 5mC DNA methylation has not yet been identified in Phytophthora, the reversible processes of acetylation/deacetylation of histone proteins seem to play a pivotal role in the epigenetic control of gene expression in oomycetes. To explore this issue, we review the structure, diversity, and phylogeny of histone acetyltransferases (HATs) and histone deacetylases (HDACs) in six plant‐damaging Phytophthora species: P. capsici, P. cinnamomi, P. infestans, P. parasitica, P. ramorum, and P. sojae. To further integrate and improve our understanding of the phylogenetic classification, evolutionary relationship, and functional characteristics, we supplement this review with a comprehensive view of HATs and HDACs using recent genome‐ and proteome‐level databases. Finally, the potential functional role of transcriptional reprogramming mediated by epigenetic changes during Phytophthora species saprophytic and parasitic phases under nitro‐oxidative stress is also briefly discussed. [ABSTRACT FROM AUTHOR]

University students often struggle to understand the role of water in plant cells. In particular, osmosis and plasmolysis appear to be challenging topics. This study attempted to identify student difficulties (including misconceptions) concerning osmosis and plasmolysis and examined to what extent the difficulties could be revised during a plant physiology course. A questionnaire was developed to monitor university students' conceptual knowledge before and after a course, and both qualitative and quantitative data were obtained. The data were analyzed using the constant comparison technique and descriptive statistics. Students were found to come to university with many misconceptions that had accumulated during their education. These misconceptions are extremely difficult to change during the traditional course, which comprises lectures and practical exercises. Students' misconceptions originate from commonly used sources such as textbooks, which are perceived as being reliable. Effective teaching of water relations in plant cells could include such didactic methods as "questioning the author," which allow teachers to monitor students' knowledge and help students acquire a more scientific understanding of key concepts.

MicroRNAs are small, noncoding RNA molecules that regulate the expression of their target genes. The MIR444 gene family is present exclusively in monocotyledons, and microRNAs444 from this family have been shown to target certain MADS‐box transcription factors in rice and barley. We identified three barley MIR444 (MIR444a/b/c) genes and comprehensively characterised their structure and the processing pattern of the primary transcripts (pri‐miRNAs444). Pri‐microRNAs444 undergo extensive alternative splicing, generating functional and nonfunctional pri‐miRNA444 isoforms. We show that barley pri‐miRNAs444 contain numerous open reading frames (ORFs) whose transcripts associate with ribosomes. Using specific antibodies, we provide evidence that selected ORFs encoding PEP444a within MIR444a and PEP444c within MIR444c are expressed in barley plants. Moreover, we demonstrate that CRISPR‐associated endonuclease 9 (Cas9)‐mediated mutagenesis of the PEP444c‐encoding sequence results in a decreased level of PEP444 transcript in barley shoots and roots and a 5‐fold reduced level of mature microRNA444c in roots. Our observations suggest that PEP444c encoded by the MIR444c gene is involved in microRNA444c biogenesis in barley. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is an essential macronutrient for the growth and development of plants, but excessive use of nitrogen fertiliser in agriculture can result in environmental pollution. As a preferred nitrogen form, ammonium (NH4 +) is absorbed from the soil by the plants through ammonium transporters (AMTs). Therefore, it is important to explore AMTs to improve the efficiency of plant N utilisation. Here, we performed a comprehensive genome-wide analysis to identify and characterise the AMT genes in barley (HvAMTs), which is a very important cereal crop. A total of seven AMT genes were identified in barley and further divided into two subfamilies (AMT1 and AMT2) based on phylogenetic analysis. All HvAMT genes were distributed on five chromosomes with only one tandem duplication. HvAMTs might play an important role in plant growth, development, and various stress responses, as indicated by cisregulatory elements, miRNAs, and protein interaction analysis. Further, we analysed the expression pattern of HvAMTs in various developmental plant tissues, which indicated that AMT1 subfamily members might play a major role in the uptake of NH4 + from the soil through the roots in barley. Altogether, these findings might be helpful to improve the barley crop with improved nitrogen use efficiency, which is not only of great significance to the crop but also for land and water as it will reduce N fertiliser pollution in the surrounding ecosystem. [ABSTRACT FROM AUTHOR]

Crop losses caused by climate change and various (a)biotic stressors negatively affect agriculture and crop production. Therefore, it is vital to develop a proper understanding of the complex response(s) to (a)biotic stresses and delineate them for each crop plant as a means to enable translational research. In plants, the improvement of crop quality by m6A editing is believed to be a promising strategy. As a reaction to environmental changes, m6A modification showed a high degree of sensitivity and complexity. We investigated differences in gene medleys between dark-induced leaf senescence (DILS) and developmental leaf senescence in barley, including inter alia RNA modifications active in DILS. The identified upregulated genes in DILS include RNA methyltransferases of different RNA types, embracing enzymes modifying mRNA, tRNA, and rRNA. We have defined a decisive moment in the DILS model which determines the point of no return, but the mechanism of its control is yet to be uncovered. This indicates the possibility of an unknown additional switch between cell survival and cell death. Discoveries of m6A RNA modification changes in certain RNA species in different stages of leaf senescence may uncover the role of such modifications in metabolic reprogramming. Nonetheless, there is no such data about the process of leaf senescence in plants. In this scope, the prospect of finding connections between the process of senescence andm6A modification of RNA in plants seems to be compelling. [ABSTRACT FROM AUTHOR]

Flooding entails different stressful conditions leading to low oxygen availability for respiration and as a result plants experience hypoxia. Stress imposed by hypoxia affects cellular metabolism, including the formation of toxic metabolites that dramatically reduce crop productivity. Aldehyde dehydrogenases (ALDHs) are a group of enzymes participating in various aspects of plant growth, development and stress responses. Although we have knowledge concerning the multiple functionalities of ALDHs in tolerance to various stresses, the engagement of ALDH in plant metabolism adjustment to hypoxia is poorly recognized. Therefore, we explored the ALDH gene superfamily in the model plant Arabidopsis thaliana. Genome-wide analyses revealed that 16 AtALDH genes are organized into ten families and distributed irregularly across Arabidopsis 5 chromosomes. According to evolutionary relationship studies from different plant species, the ALDH gene superfamily is highly conserved. AtALDH2 and ALDH3 are the most numerous families in plants, while ALDH18 was found to be the most distantly related. The analysis of cis-acting elements in promoters of AtALDHs indicated that AtALDHs participate in responses to light, phytohormones and abiotic stresses. Expression profile analysis derived from qRT-PCR showed the AtALDH2B7, AtALDH3H1 and AtALDH5F1 genes as the most responsive to hypoxia stress. In addition, the expression of AtALDH18B1, AtALDH18B2, AtALDH2B4, and AtALDH10A8 was highly altered during the post-hypoxiareoxygenation phase. Taken together, we provide comprehensive functional information on the ALDH gene superfamily in Arabidopsis during hypoxia stress and highlight ALDHs as a functional element of hypoxic systemic responses. These findings might help develop a framework for application in the genetic improvement of crop plants. [ABSTRACT FROM AUTHOR]