Designing Novel Breeding Strategies for Producing High-Oil Crops Based on a Molecular Understanding of Triacylglycerol Metabolism

Seeds are storage organ in plants and main resource of plant oils to human civilization and the demand of plant oils are increasing yearly and expansion of the production capacity is an urgent issue worldwide. Thus, it is necessary to improve oil yields per unit area and generation of crops with high-oil content is needed. Arabidopsis thaliana plays a vital role in advancement of genetics and molecular biology in plant sciences. The forward and reverse genetic approaches with Arabidopsis have provided an overview of triacylglycerol metabolism. The elucidation of the overview contributes to understanding of spatiotemporal regulation of a metabolic flow of triacylglycerol metabolism in plant cell. This understanding sheds light on bottlenecks in triacylglycerol biosynthesis and provides novel clues for increasing seed triacylglycerol content. Recent advance in metabolic engineering approaches demonstrate several evidences that triacylglycerol metabolism is coordinated with other metabolisms. Most notably, triacylglycerol biosynthesis competes with biosynthesis of starch or seed storage proteins. These studies indicate that alterations of the metabolic pathways to avoid the competitions could be a novel concept for increasing seed oil content

AtUBL5 regulates growth and development through pre-mRNA splicing in Arabidopsis thaliana

Ubiquitin-like proteins play important roles in the regulation of many biological processes. UBL5 (Ubiquitin-like protein 5)/Hub1 (Homologous to ubiquitin 1), a member of the ubiquitin family, acts as a ubiquitin-like modifier on a specific target, the spliceosomal protein Snu66, in yeast and human cells. The 22nd aspartic acid (Asp22) is involved in the attachment of Hub1 to the Hub1 interaction domain (HIND) of Snu66 in yeast to modulate spliceosomal activity. Hub1 differs from other modifiers which interact covalently with their targets. It modulates pre-mRNA splicing by binding to Snu66 non-covalently in both yeast and human cells. However, the molecular mechanisms of Hub1-mediated pre-mRNA splicing in plant systems remains unclear. To better understand the function of Hub1 in plants, we examined the role of this ubiquitin-like modifier in Arabidopsis thaliana, which has two Hub1 homologues. Arabidopsis UBL5/Hub1(UBL5) is highly conserved at the amino acid level, compared to eukaryotic homologues in both plants and animals. In this study, phenotypic analysis of A. thaliana with reduced UBL5 gene expression, generated by RNA interference of AtUBL5a and AtUBL5b were performed. Interestingly, knock down plants of AtUBL5 showed abnormalities in root elongation, plant development, and auxin response. AtUBL5b is highly expressed in the vascular tissue of the leaf, stem, and root tissue. Yeast two-hybrid analysis revealed that AtUBL5a and AtUBL5b interact with the putative splicing factor AtPRP38 through its C-terminal domain (AtPRP38C). Knock down of AtUBL5b resulted in a pattern of insufficient pre-mRNA splicing in several introns of AtCDC2, and in introns of IAA1, IAA4, and IAA5. Defects of pre-mRNA splicing in an AtPRP38 mutant resulted in an insufficient pre-mRNA splicing pattern in the intron of IAA1. Based on these results, we showed that AtUBL5b positively regulates plant root elongation and development through pre-mRNA splicing with AtPRP38C in A. thaliana

Off-center rattling and thermoelectric properties of type-II clathrate (K, Ba)(24)(Ga, Sn, square)(136) single crystals

We report the synthesis and temperature-dependent structural, transport, and thermal properties of type-II clathrate K8+xBa16-xGa40-ySn96-z square(y+z) (1.2 <= x <= 2.8, 2.0 <= y <= 3.3, 0.8 <= z <= 6.6, square = framework vacancy). Single-crystal x-ray diffraction analysis reveals that the guest K+ and Ba2+ ions are preferentially incorporated into the hexakaidecahedral cages and dodecahedral cages, respectively. The guest site in the former splits into four sites 0.67 angstrom away from the center to the 32e site of the cage. The splitting is consistent with the presence of four minima in the electrostatic potential in the hexakaidecahedron. The thermopower is negative and relatively large, -50 similar to -120 mu V/K at 300 K, indicating that the dominant charge carriers are electrons. The thermal conductivity displays a glasslike behavior with a plateau at around 20 K. The analysis of the specific heat indicates that the motion of the K+ ion in the hexakaidecahedron can be described by the soft-potential model, including the tunneling term. The characteristic energy of 21 K for the soft mode is as low as that of the off-center rattling of the Ba2+ ion in type-I clathrate Ba8Ga16Sn30. The present result on the type-II clathrate verifies the idea that the low-energy off-center rattling in oversized cages of intermetallic clathrates couples to the acoustic phonons to lead to the glasslike thermal conductivity

The Plant Organelles Database 2 (PODB2): An Updated Resource Containing Movie Data of Plant Organelle Dynamics

The Plant Organelles Database (PODB) was launched in 2006 and provides imaging data of plant organelles, protocols for plant organelle research and external links to relevant websites. To provide comprehensive information on plant organelle dynamics and accommodate movie files that contain time-lapse images and 3D structure rotations, PODB was updated to the next version, PODB2 (http://podb.nibb.ac.jp/Organellome). PODB2 contains movie data submitted directly by plant researchers and can be freely downloaded. Through this organelle movie database, users can examine the dynamics of organelles of interest, including their movement, division, subcellular positioning and behavior, in response to external stimuli. In addition, the user interface for access and submission has been enhanced. PODB2 contains all of the information included in PODB, and the volume of data and protocols deposited in the PODB2 continues to grow steadily. Moreover, a new website, Plant Organelles World (http://podb.nibb.ac.jp/Organellome/PODBworld/en/index.html), which is based on PODB2, was recently launched as an educational tool to engage members of the non-scientific community such as students and school teachers. Plant Organelles World is written in layman's terms, and technical terms were avoided where possible. We would appreciate contributions of data from all plant researchers to enhance the usefulness of PODB2 and Plant Organelles World

Sucrose starvation induces microautophagy in plant root cells

Abstract Autophagy is an essential system for degrading and recycling cellular components for survival during starvation conditions. Under sucrose starvation, application of a papain protease inhibitor E-64d to the Arabidopsis root and tobacco BY-2 cells induced the accumulation of vesicles, labeled with a fluorescent membrane marker FM4-64. The E-64d-induced vesicle accumulation was reduced in the mutant defective in autophagy-related genes ATG2, ATG5, and ATG7, suggesting autophagy is involved in the formation of these vesicles. To clarify the formation of these vesicles in detail, we monitored time-dependent changes of tonoplast, and vesicle accumulation in sucrose-starved cells. We found that these vesicles were derived from the tonoplast and produced by microautophagic process. The tonoplast proteins were excluded from the vesicles, suggesting that the vesicles are generated from specific membrane domains. Concanamycin A treatment in GFP-ATG8a transgenic plants showed that not all FM4-64-labeled vesicles, which were derived from the tonoplast, contained the ATG8a-containing structure. These results suggest that ATG8a may not always be necessary for microautophagy.This study was supported by the National Science Centre, Poland [UMO-2016/21/P/NZ9/01089 to SG-Y (the project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 665778) and UMO-2016/23/B/NZ1/01847 to KeY]; the Foundation for Polish Science (TEAM/2017-4/41 to KeY); KAKENHI from the Japan Society for the Promotion of Science, Japan (JP15J40032 to SG-Y, JP17K07457 to SM, and JP15H05776 to IH-N); and KAKENHI from the Ministry of Education, Culture, Sports, Science and Technology, Japan (JP26111523 to SG-Y); as well as the institutional support provided from the National Institute for Basic Biology (NIBB), Kyoto University, and Małopolska Centre of Biotechnology, Jagiellonian University. Next-generation sequencing was supported by NIBB Collaborative Research Programs 11-711

Interplay between thermoelectric and structural properties of type-I clathrate K8Ga8Sn38 single crystals

We report structural, transport, and thermal properties of type-I clathrate K8Ga8Sn38 single crystals grown by the self-flux method. Single-crystal x-ray diffraction analysis confirmed that the guest K+ ion locates on the center in the tetrakaidecahedron composed of Ga and Sn atoms. The thermopower is largely negative,-200μ V/K at room temperature, irrespective of the flux used during growth Ga or Sn . The thermal conductivity κ(T) exhibits a large peak at 14 K. These observations in K8Ga8Sn38 are ontrasting with the splitting of the guest site and the glasslike behavior in κ(T) reported for type-I Ba8Ga16Sn30 although the free space for the guest is almost the same in both compounds. The electrostatic potential for the tetrakaidecahedron was calculated using the occupation probabilities of Ga ions in the three sites on the cage. It is found that the off-centered state is stabilized for the Ba2+ ions in Ba8Ga16Sn30 by the partial occupation of Ga anion in the 16i site while the on-center state for K8Ga8Sn38 is stabilized by the strongly preferred occupation of Ga anions in the 6c site. We conclude that the charge distribution on the cage is crucial for the splitting of the guest site into off-center positions in the tetrakaidecahedron of the type-I clathrate

Male Breast Cancer Originating in an Accessory Mammary Gland in the Axilla: A Case Report

Carcinoma of an accessory mammary gland is an extremely rare tumor. A 61-year-old male patient presented with a hard mass measuring 85 mm × 51 mm in the left axilla. Incisional biopsy histopathologically showed an adenocarcinoma compatible with breast carcinoma originating in an accessory mammary gland. Systemic examinations revealed no evidence of malignant or occult primary lesion in the bilateral mammary glands or in other organs. Neoadjuvant chemotherapy was performed for the locally advanced axillary tumor and reduced the tumor to 55 mm in size, and, then, he could undergo complete resection with a negative surgical margin in combination with reconstructive surgery to fill the resulting skin defect with a local flap of the latissimus dorsi muscle. The patient has presented with no metastatic lesion in four years since the operation. This unusual case shows that neoadjuvant chemotherapy is an effective and tolerated therapy for advanced accessory breast cancer in the axilla

Primary Chest Wall Abscess Mimicking a Breast Tumor That Occurred after Blunt Chest Trauma: A Case Report

Primary chest wall abscess occurring after blunt chest trauma is rare. We present the case of a 50-year-old woman who presented with a swelling in her left breast. The patient had experienced blunt chest trauma 2 months back. Needle aspiration revealed pus formation in the patient’s chest. Computed tomography revealed a mass in the lower region of the left mammary gland, with thickening of the parietal pleura and skin and fracture of the fifth rib under the abscess. Following antibiotic administration and irrigation of the affected region, surgical debridement was performed. During surgery, we found that the pectoralis major muscle at the level of the fifth rib was markedly damaged, although the necrotic tissue did not contact the mammary gland. We diagnosed the lesion as a chest wall abscess that occurred in response to blunt chest trauma. Her postoperative course was uneventful. There has been no recurrence for six months after surgery

Pexophagy suppresses ROS-induced damage in leaf cells under high-intensity light

Although light is essential for photosynthesis, it has the potential to elevate intracellular levels of reactive oxygen species (ROS). Since high ROS levels are cytotoxic, plants must alleviate such damage. However, the cellular mechanism underlying ROS-induced leaf damage alleviation in peroxisomes was not fully explored. Here, we show that autophagy plays a pivotal role in the selective removal of ROS-generating peroxisomes, which protects plants from oxidative damage during photosynthesis. We present evidence that autophagy-deficient mutants show light intensity-dependent leaf damage and excess aggregation of ROS-accumulating peroxisomes. The peroxisome aggregates are specifically engulfed by pre-autophagosomal structures and vacuolar membranes in both leaf cells and isolated vacuoles, but they are not degraded in mutants. ATG18a-GFP and GFP-2×FYVE, which bind to phosphatidylinositol 3-phosphate, preferentially target the peroxisomal membranes and pre-autophagosomal structures near peroxisomes in ROS-accumulating cells under high-intensity light. Our findings provide deeper insights into the plant stress response caused by light irradiation