The success or failure of food technologies in society depends to a large extent on the public interest, concerns, images, and expectations surrounding them. This paper delves into the landscape of ...public attitudes towards gene-edited foods in Japan, exploring the reasons behind the acceptance or rejection of these products. A literature review and preliminary findings from a survey conducted in Japan in 2022, aim to identify key issues crucial for evaluating societal acceptance of gene-edited foods. The study showed that the public view gene-edited foods as somewhat unnatural, but upon closer examination, significant variation in attitudes was observed among respondents. Some respondents expressed a favorable perception towards gene-edited foods, particularly those that benefit consumers, while others expressed concerns about its perceived artificiality. Moreover, a significant number of respondents displayed indifference or lack of clear perspective regarding gene-edited foods. These findings reflect the complex relationship between public attitudes, naturalness, and social acceptance of gene-edited foods. Furthermore, the study indicates the importance of paying close attention to those who refrain from expressing their viewpoints in the survey. This nuanced landscape warrants further exploration.
The regulation of leaf size has been studied for decades. Enhancement of post-mitotic cell expansion triggered by impaired cell proliferation in Arabidopsis is an important process for leaf size ...regulation, and is known as compensation. This suggests a key interaction between cell proliferation and cell expansion during leaf development. Several studies have highlighted the impact of this integration mechanism on leaf size determination; however, the molecular basis of compensation remains largely unknown. Previously, we identified extra-small sisters (xs) mutants which can suppress compensated cell enlargement (CCE) via a specific defect in cell expansion within the compensation-exhibiting mutant, angustifolia3 (an3). Here we revealed that one of the xs mutants, namely xs2, can suppress CCE not only in an3 but also in other compensation-exhibiting mutants erecta (er) and fugu2. Molecular cloning of XS2 identified a deleterious mutation in CATION CALCIUM EXCHANGER 4 (CCX4). Phytohormone measurement and expression analysis revealed that xs2 shows hyper activation of the salicylic acid (SA) response pathway, where activation of SA response can suppress CCE in compensation mutants. All together, these results highlight the regulatory connection which coordinates compensation and SA response.
During leaf development, the timing of transition from cell proliferation to expansion is an important factor in determining the final organ size. However, the regulatory system involved in this ...transition remains less understood. To get an insight into this system, we investigated the compensation phenomenon, in which the cell number decreases while the cell size increases in organs with determinate growth. Compensation is observed in several plant species suggesting coordination between cell proliferation and expansion. In this study, we examined an Arabidopsis mutant of
(
)/
, a positive regulator of cell proliferation, which exhibits the compensation. Though the AN3 role has been extensively investigated, the mechanism underlying excess cell expansion in the
mutant remains unknown. Focusing on the early stage of leaf development, we performed kinematic, cytological, biochemical, and transcriptome analyses, and found that the cell size had already increased during the proliferation phase, with active cell proliferation in the
mutant. Moreover, at this stage, chloroplasts, vacuoles, and xylem cells developed earlier than in the wild-type cells. Transcriptome data showed that photosynthetic activity and secondary cell wall biosynthesis were activated in
proliferating cells. These results indicated that precocious cell differentiation occurs in
cells. Therefore, we suggest a novel AN3 role in the suppression of cell expansion/differentiation during the cell proliferation phase.
Domatia are plant structures within which organisms reside. Callicarpa saccata (Lamiaceae) is the sole myrmecophyte, or 'ant plant', that develops foliar (leaf-borne) myrmeco-domatia in this genus. ...In this work we examined domatium development in C. saccata to understand the developmental processes behind pouch-like domatia.
Scanning electron microscopy, sectioning and microcomputed tomography were carried out to compare the leaves of C. saccata with those of the closely related but domatia-less myrmecophyte Callicarpa subaequalis, both under cultivation without ants.
Callicarpa saccata domatia are formed as a result of excess cell proliferation at the blade/petiole junctions of leaf primordia. Blade/petiole junctions are important meristematic sites in simple leaf organogenesis. We also found that the mesophyll tissue of domatia does not clearly differentiate into palisade and spongy layers.
Rather than curling of the leaf margins, a perturbation of the normal functioning of the blade/petiole junction results in the formation of domatium tissue. Excess cell proliferation warps the shape of the blade and disturbs the development of the proximal-distal axis. This process leads to the generation of distinct structures that facilitate interaction between C. saccata and ants.
A tropical small tree,
Callicarpa saccata,
is known to have a symbiotic relationship with ants. It has sac-like structures at the base of the leaves that are inhabited by ants. No other species has ...been determined to be a myrmecophyte among the ca. 140 species of this genus. However, our recent field investigation discovered that two other species on Borneo (
C. barbata
and
C. teneriflora
) have hollow stems, which seem to be inhabited by ants. We observed the morphological features of these species in relation to their usage by ants, and became convinced that they are mymecophytic species. The molecular phylogenetic analyses using ITS and chloroplast regions suggest that
C. saccata
and
C. teneriflora
are closely related, but the differences in the myrmecophytic features of these species should be noted.
The success or failure of food technologies in society depends to a large extent on the public interest, concerns, images, and expectations surrounding them. This paper delves into the landscape of ...public attitudes towards gene-edited foods in Japan, exploring the reasons behind the acceptance or rejection of these products. A literature review and preliminary findings from a survey conducted in Japan in 2022, aim to identify key issues crucial for evaluating societal acceptance of gene-edited foods. The study showed that the public view gene-edited foods as somewhat unnatural, but upon closer examination, significant variation in attitudes was observed among respondents. Some respondents expressed a favorable perception towards gene-edited foods, particularly those that benefit consumers, while others expressed concerns about its perceived artificiality. Moreover, a significant number of respondents displayed indifference or lack of clear perspective regarding gene-edited foods. These findings reflect the complex relationship between public attitudes, naturalness, and social acceptance of gene-edited foods. Furthermore, the study indicates the importance of paying close attention to those who refrain from expressing their viewpoints in the survey. This nuanced landscape warrants further exploration.
Thermus thermophilus
(
T
.
thermophilus
) HB27 is an extreme thermophile that grows optimally at 65–72 °C. Heat-induced DNA lesions are expected to occur at a higher frequency in the genome of
T
.
...thermophilus
than in those of mesophiles; however, the mechanisms underlying the maintenance of genome integrity at high temperatures remain poorly understood. The study of mutation spectra has become a powerful approach to understanding the molecular mechanisms responsible for DNA repair and mutagenesis in mesophilic species. Therefore, we developed a
supF
-based system to detect a broad spectrum of mutations in
T
.
thermophilus
. This system was validated by measuring spontaneous mutations in the wild type and a
udgA
,
B
double mutant deficient in uracil-DNA glycosylase (UDG) activity. We found that the mutation frequency of the
udgA
,
B
strain was 4.7-fold higher than that of the wild type and G:C→A:T transitions dominated, which was the most reasonable for the mutator phenotype associated with the loss of UDG function in
T
.
thermophilus
. These results show that this system allowed for the rapid analysis of mutations in
T
.
thermophilus
, and may be useful for studying the molecular mechanisms responsible for DNA repair and mutagenesis in this extreme thermophile.
Among plants and animals, cell size is restricted at the tissue level. Especially in a tissue where cells are actively dividing, they maintain a uniform size by the coordination of cell division and ...cell growth. In the Arabidopsis inflorescence meristem, which can be observed for several days under confocal microscopy, cells often divide unevenly and cell size variation of daughter cells is greater than that of mother cells. This variation is, however, reduced in subsequent cell cycles by changing cell cycle length or relative growth rate (RGR), depending on cell size. Several studies combined observation with mathematical models and indicated that cell size-dependent cell cycle regulation could maintain cell size regardless of variation in daughter cell size or RGR. In addition, cells need to properly regulate their size in response to environmental stress. TOR (target of rapamycin) pathway or responses to phytohormones would be involved in this regulation because those are activated by environmental signals and affect cell cycle or cell growth. It is also suggested that altered meristem cell size may influence gene expression pattern or tissue-level molecule gradient. Therefore, cell size regulation in the meristem should have an important role in organogenesis.
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