Growth and photosynthetic traits of hybrid larch F1 (Larix gmelinii var. japonica x L. kaempferi) under elevated CO2 concentration with low nutrient availability

The hybrid larch F(1) (Larix gmelinii var. japonica × Larix kaempferi) is considered one of the most important tree species not only for timber production but also as an afforestation material for severe conditions such as infertile soil. To predict the ability of hybrid larch F(1) as an afforestation material under potential climates in the future, it is important to understand the response of hybrid larch F(1) to elevated CO(2) concentration ([CO(2)]) under low nutrient availability. Three-year-old seedlings of hybrid larch F(1) were grown under two different levels of [CO(2)], 360 (ambient) and 720 μmol mol(-1) (elevated), in combination with two different levels of nitrogen (N) supply (0 and 30 kg ha(-1)) for one growing season. Elevated [CO(2)] reduced the maximum rates of carboxylation and electron transport in the needles. Net photosynthetic rates at growth [CO(2)] (i.e., 360 and 720 μmol mol(-1) for ambient and elevated treatment, respectively) did not differ between the two CO(2) treatments. Reductions in N content and N use efficiency to perform photosynthetic functions owing to the deficiency of nutrients other than N, such as P and K, and/or increase in cell wall mass were considered factors of photosynthetic down-regulation under elevated [CO(2)], whereas stomatal closure little affected the photosynthetic down-regulation. Although we observed strong down-regulation of photosynthesis, the dry matter increase of hybrid larch F(1) seedlings was enhanced under elevated [CO(2)]. This is mainly attributable to the increase in the amount of needles on increasing the number of sylleptic branches. These results suggest that elevated CO(2) may increase the growth of hybrid larch F(1) even under low nutrient availability, and that this increase may be regulated by changes in both crown architecture and needle photosynthesis, which is mainly affected not by stomatal limitation but by biochemical limitation.     

SGT1 and HSP90 are essential for age-related non-host resistance of Nicotiana benthamiana against the oomycete pathogen Phytophthora infestans

The oomycete pathogen, Phytophthora infestans, is the causal agent of potato late blight, which is one of the most destructive and economically important plant diseases. We investigated the interaction between P. infestans and Solanaceous model plant Nicotiana benthamiana. Mature N. benthamiana plants were resistant to 8 isolates of P. infestans, whereas relatively young plants were susceptible to all isolates. Analysis with virus-induced gene silencing (VIGS) indicated that NbSGT1 and NbHSP90, genes essential for the function of R proteins, are required for the resistance of N. benthamiana to P. infestans. NbSGT1 was also required for the production of reactive oxygen species (ROS), hypersensitive cell death and expression of NbEAS, a gene for phytoalexin biosynthesis, induced by INF1, a secretory protein derived from P. infestans. These results suggested that N. benthamiana possibly possesses a broad-spectrum R protein against P. infestans, which requires an SGT1/HSP90-dependent mechanism, for the recognition of a conserved molecular pattern of P. infestans.     

Occurrence of two distinct Theileria lineages in sika deer (Cervus nippon) of Iwate Prefecture, Japan

In the present study, we tried to detect protozoan blood parasites from the liver or blood of 141 Japanese sika deer (Cervus nippon) in Iwate Prefecture of Japan by polymerase chain reaction. Approximately 500-bp amplicons were obtained in 76 (53.9%) of 141 samples by amplification for V4 hyper-variable regions of the 18S rRNA gene, and the amplicons were considered to be DNA of Theileria species. The complete nucleotide sequences (1701-bp) of the 18S rRNA gene were determined in 25 samples and were divided into 8 genotypes that were phylogenetically separated into two distinct lineages showing a monophyletic relation. The two lineages of Theileria were detected in different rates (12 and 88%) from sika deer in Iwate Prefecture.     

Malignant mixed tumor in the salivary gland of a cat

The presence of a malignant mixed tumor, also known as a carcinosarcoma, in the salivary gland is very rare. Such tumors, which are typically aggressive, are characterized by the presence of carcinomatous and sarcomatous components. A 9-year-old neutered female domestic short-haired cat presented with swelling in the right mandibular lesion that had rapidly enlarged over the previous 3 weeks. Physical examination revealed a large, fluctuated and painless subcutaneous swelling that was associated with a firm mass. Radiographs of the head revealed a soft-tissue density that involved faint circular calcific opacity. Contrast-enhanced computed tomography revealed that the peripheral capsulated cystic area had a contrast enhanced region without bone lysis. The cat received a total excision of the mass and postoperative radiotherapy. Histopathological analysis of the mass revealed that it was a malignant mixed tumor. Metastasis to the lung was discovered 7 weeks later, at which time treatment was stopped.     

Degradation of an acylated starch-plastic mulch film in soil and impact on soil microflora

Degradation of an acylated starch-plastic mulch film was evaluated in two soil types, a gray lowland soil (A) and a volcanic andosol (V). Weight loss, tensile strength (TS) loss and loss of percentage elongation (%E) were measured under laboratory conditions (black and white mulch films), and in the field (black films). Changes in the counts of total bacteria, total fungi, gram-negative bacteria, total Fusarium, ATP (adenosine triphosphate) content, % nitrification, pH (H₂O), and total C and total N contents were determined at 4,8, 12, and 20 months in the field test soils where the mulch was repeatedly applied, and compared with controls. Film weight loss was greater in soil V than in soil A in both the laboratory and the field, and the losses were greater in the laboratory than in the field in both soils A and V. Significant TS losses and considerable %E losses were observed. Values were similar in the laboratory and in the field. No significant changes in the counts of bacteria, fungi, gram-negative bacteria, and Fusarium were observed. The ATP content of the test soils increased slightly compared with the initial values. The ATP content in the control soils initially fell, and then increased in response to weeding. Nitrification remained almost unchanged in the test soils, but fell in the control soils until the last sampling. However, the mulch film underwent a definite process of degradation in the soils, with great loss of physical properties and lesser weight loss. This degradation had no adverse impact on the soil microflora.     

Hydrocephalus and syringomyelia in a cat.

A 3-month-old male Japanese cat with feline parvovirus infection, showing central and cervical nerve abnormalities, was diagnosed as hydrocephalus and syringomyelia by use of magnetic resonance imaging (MRI). The cat was maintained clinically by medical treatment even though he could not stand. The MRI scans obtained about 5 months later showed that the ventricles had increased in size and the cervical syrinx had extended into the thoracic spinal cord. Ventriculoperitoneal (VP) shunt was performed. One week after surgery, neurological conditions had improved. At the postoperative MR images, the ventricles had decreased in size and the syrinx in the cervical and thoracic spinal cord could no longer be seen. The cat was still alive and was able to walk well.     

Anatomical evaluation of hepatic vascular system in healthy beagles using X-ray contrast computed tomography

Liver contrast X-ray computed tomography (CT) has been used for evaluation of hepatic vessels for liver transplantation, liver lobectomy, interventional radiology and diagnosis of hepatocellular carcinoma in humans. However, there remains scant available anatomical information on normal hepatic vessels in the veterinary field. In this study, visualization of hepatic vessels was evaluated in 32 normal beagle dogs by X-ray contrast CT using triple phase images. The following hepatic vessels were clearly visualized: arterial, portal and hepatic veins. With regards to the running patterns of the portal vein and hepatic vein, there were no significant differences between the dogs. However, the hepatic artery exhibited some differences in each dog. In particular, the hepatic artery of the quadrate lobe and the right lateral lobe had many running patterns. The results of the present study could be useful for veterinary diagnosis, surgery and interventional radiology.     

Primary chondrosarcoma in the skull of a dog

Chondrosarcoma of the skull is a rare primary malignant tumor that is slow-growing, but locally aggressive. A 5-year-old, golden retriever was presented to our hospital with a swelling in the left side of her head, and the swelling had slowly enlarged over the previous month. There were no significant changes on the neurological examination. A computed tomography scan revealed a large mass involving bone destruction and prominent matrix mineralization. T1-weighted magnetic resonance imaging showed a slightly low-signal intensity area and a T2-weighted image revealed marked, high-signal intensity. There was compression of the adjacent brain parenchyma. Histopathological examination confirmed the lesion to be a chondrosarcoma.