Tradeoff between shade adaptation and mitigation of photoinhibition in leaves of Quercus mongolica and Acer mono acclimated to deep shade

We investigated susceptibility to photoinhibition in leaves acclimated to different light regimes in intermediately shade-tolerant Japanese oak (Quercus mongolica Fisch. ex Turcz. var. crispula (Blume) Ohashi) and shade-tolerant Japanese maple (Acer mono Maxim. var. glabrum (Lév. et Van't.) Hara), to elucidate adaptability to gap formation in leaves differing in shade acclimation. We hypothesized that there is a tradeoff between shade adaptation and capacity to mitigate photoinhibition associated with leaf morphology. We simultaneously measured chlorophyll fluorescence and gas exchange in seedlings that had been grown in full sunlight (open), 10% of full sun (moderate shade) and 5% of full sun (deep shade). Shade-tolerant A. mono adapted to deep shade through changes in leaf morphology, lowering its leaf mass per area (LMA), but Q. mongolica showed little change in LMA between moderate and deep shade. Photochemical quenching (qP) did not differ between species in full sunlight and moderate shade; however, in deep shade, qP of Q. mongolica was higher than that of A. mono, suggesting that Q. mongolica grown in deep shade is less susceptible to photoinhibition at gap formation. This is consistent with the finding that chronic photoinhibition 3 days after the transfer to full sunlight, indicated by the decrease in maximum photochemical efficiency, Fv/Fm, at predawn, was less in deep-shade-grown Q. mongolica than in deep shade-grown A. mono. In deep shade, the electron transport rate (ETR) of Q. mongolica was higher than that of A. mono, whereas thermal energy dissipation through photosystem II antennae, indicated by non-photochemical quenching, was lower in Q. mongolica than in A. mono. In deep shade, the greater ETR capacity in Q. mongolica in association with higher LMA and higher leaf N content could contribute to maintaining high qP and mitigating photoinhibition. These results indicate that, by maintaining a high electron transport capacity even in deep shade, the gap-dependent and intermediate-shade-tolerant Q. mongolica trades improved shade adaptation for higher growth potential when a gap event occurs.     

Determination of seven organosulfur compounds in garlic by high-performance liquid chromatography

The properties of garlic (Allium sativum L.) are attributed to organosulfur compounds. Although these compounds change during cultivation and storage, there is no report of their simultaneous analysis. Here, a newly developed analytical method with a rapid and simple sample preparation to determine four sulfoxides and three gamma-glutamyl peptides in garlic is reported. All garlic samples were simply extracted with 90% methanol solution containing 0.01 N hydrochloric acid and prepared for analysis. Alliin, isoalliin, methiin, cycloalliin, and gamma-l-glutamyl-S-methyl-l-cysteine were determined by normal-phase HPLC using an aminopropyl-bonded column. gamma-l-Glutamyl-S-(2-propenyl)-l-cysteine and gamma-l-glutamyl-S-(trans-1-propenyl)-l-cysteine were separated on an octadecylsilane column. The overall recoveries were 97.1-102.3%, and the relative standard deviation values of intra- and interday precision were lower than 2.6 and 4.6%, respectively. This newly developed method offers some advantages over the currently accepted techniques including specificity, speed, and ease of use and would be useful for chemical and biological studies of garlic and its preparations.     

Neuronal pathway from the liver modulates energy expenditure and systemic insulin sensitivity

Coordinated control of energy metabolism and glucose homeostasis requires communication between organs and tissues. We identified a neuronal pathway that participates in the cross talk between the liver and adipose tissue. By studying a mouse model, we showed that adenovirus-mediated expression of peroxisome proliferator-activated receptor (PPAR)-g2 in the liver induces acute hepatic steatosis while markedly decreasing peripheral adiposity. These changes were accompanied by increased energy expenditure and improved systemic insulin sensitivity. Hepatic vagotomy and selective afferent blockage of the hepatic vagus revealed that the effects on peripheral tissues involve the afferent vagal nerve. Furthermore, an antidiabetic thiazolidinedione, a PPARg agonist, enhanced this pathway. This neuronal pathway from the liver may function to protect against metabolic perturbation induced by excessive energy storage.     

Possible association of glaucoma with pectinate ligament dysplasia and narrowing of the iridocorneal angle in Shiba Inu dogs in Japan

The purpose of the study was to describe the shape of the pectinate ligament (PL) and to estimate the width of the iridocorneal angle (ICA) in glaucomatous and non-glaucomatous eye of Shiba Inu dogs in Japan. One hundred fourteen Shiba Inu dogs were presented to the Veterinary Medical Center at the University of Tokyo between June 1998 and June 2003. Among these, 46 dogs had glaucoma; the remaining 68 dogs were presented for routine vaccinations or heartworm testing and were used as a control population. Complete ophthalmic examination and gonioscopy were performed in all the dogs. PL and ICA were evaluated by gonioscopy and goniophotographs. Of the 46 dogs with glaucoma, 17 (37%) were affected bilaterally, and 29 (63%) were affected unilaterally. Of the 29 dogs with unilateral glaucoma, the ICA of the normotensive eye was slightly narrow in 2 eyes (7%), narrow in 12 eyes (41%), and closed in 15 eyes (52%). Among the normotensive control group, the ICA was open in 13 dogs (19%), slightly narrow in 29 (43%), narrow in 22 (32%), and closed in 4 (6%). In dogs with narrow and slightly narrow ICAs, the PLs were thickened, and in some cases, formed a solid sheet. The majority of dogs with glaucoma had changes in both ICA and PL. A narrow or slightly narrow ICA was also detected in the majority of normotensive control dogs. This study suggests that ICA narrowing and PL thickening is a common abnormality in Shiba Inu dogs in Japan and may predispose those dogs to glaucoma.     

In vitro ruminal fermentation and in situ ruminal degradation of tamarind kernel powder extract residue in wethers

We examined the in vitro fermentation characteristics and in situ dry matter (DM) and crude protein (CP) degradability of tamarind kernel powder extract residue (TKPER), a by‐product of polysaccharides thickener processing. Two types of TKPER (I and II), of which the CP and neutral detergent fiber organic matter basis contents (%) were 41.4 and 42.0 and 1.4 and 0.5, respectively, were compared with dry heat soybean (SB), soybean meal (SBM) and dry soybean curd residue (SBCR). The TKPERs had significantly lower in vitro gas production compared to the other products at each observation time (P < 0.05). The in vitro DM and CP digestibility (%) of TKPER I and II were 67.7 and 64.9, and 64.5 and 58.0, respectively, significantly lower than those of SB and SBM (P < 0.05). We used four wethers (55.6 ± 4.6 kg) with ruminal cannulas to investigate the in situ degradability of TKPER I, SB, SBM and SBCR. At the ruminal outflow rate of 0.05/h, the effective degradability (%) values of the DM and CP of TKPER I were 64.1 and 49.7, respectively, which were similar to those of SBM. In conclusion, TKPER had high CP and exhibited in situ degradability similar to that of SBM, suggesting that TKPER could be used as a protein source feed.     

Health and mineral nutrition status of yaks in southern Mustang,Nepal

Biochemical values and mineral concentrations in blood plasma were investigated to evaluate the statuses of health and mineral nutrition among yaks in Mustang District, Nepal. In total, 118 plasma samples of female yaks collected in April and September/October of 2013–2015 were offered. Seventy‐four percent of yaks showed lower plasma total‐cholesterol concentrations than the lowest limit of reference range (100 mg/dL) and the values in spring (83.41 mg/dL) were lower (P < 0.05) than those in autumn (95.05 mg/dL). All the yaks had lower plasma albumin concentrations than the lowest limit of reference range (3.0 g/dL) and 66% of yaks showed lower plasma inorganic phosphorus concentrations than the critical level of phosphorus deficiency (4.5 mg/dL). Thirty‐five percent of yaks showed lower plasma calcium concentrations than the lowest limit of normal range (8 mg/dL) and the concentrations were lower in spring than in autumn (P < 0.01). Seventy‐five percent of yaks presented lower copper concentrations than the critical level (0.65 mg/L) and the concentrations were lower in spring than in autumn (P < 0.01). Since the low plasma total‐cholesterol might have indicated shortage of dry matter and energy intake, attention should be paid to the nutritional statuses of energy, phosphorus, calcium and copper in winter and early spring.     

Trichomes: interaction sites of tomato leaves with biotrophic powdery mildew pathogens

The present study aimed to explore the possibility of using the type I trichomes of tomato (Solanum lycopersicum) to monitor the infection processes of powdery mildews by microscopy. Individual trichome cells of two tomato genotypes were inoculated with pathogenic and non-pathogenic powdery mildew species, Pseudoidium neolycopersici, Erysiphe trifoliorum and Podosphaera xanthii. On the trichome cells of the tomato cultivar Moneymaker, hyphae of the pathogenic Pseudoidium neolycopersici (isolates KTP-03 and KTP-04) grew vigorously; whereas hyphal growth of the non-pathogenic Erysiphe trifoliorum and Podosphaera xanthii ceased after appressorium formation, which was associated with papilla formation and hypersensitive cell death, respectively. Similar infection processes of the tested powdery mildews were seen in Moneymaker epidermal cells. Therefore, tomato trichomes are suitable for analysing, at individual cell level, the infection processes of different pathotypes of powdery mildews and for observing the cytological responses of plants by non-pathogenic powdery mildews. On the other hand, it was observed that both isolates KTP-03 and KTP-04 failed to produce conidiophores on the hyphae elongating on Moneymaker trichomes. Similarly, no conidiophores were produced on the hyphae elongating on trichomes of Solanum peruvianum LA2172, which is resistant to KTP-03 and susceptible to KTP-04. Interestingly, delayed cell death occurred in LA2172 epidermal cells, which were attacked by KTP-03 hyphae elongating from trichomes and conidiophores were formed on new hyphae growing from the leaf epidermal cells. Thus, leaf trichomes and epidermal cells of the wild tomato species LA2172 reacted differently to the avirulent isolate KTP-03.     

Identification of Disulfide Proteins in the Salt Soluble Fraction of Rice (Oryza sativa) Seed

Evidence has been accumulating to suggest that disulfide bonding is one of the key causes of allergenicity. Recently we developed the “disulfide proteome”, a technique for the comprehensive analysis of disulfide bonding of proteins. We applied this new technique to the rice seed's salt‐soluble fraction, which has long been known to be allergenic. Most proteins in the fraction, including α‐amylase/trypsin inhibsitor, α‐ globulin, and glutelin fragments, have formed intramolecular disulfide bonds. Also, unknown proteins, including one sharing similarities with known allergens, had disulfide bonds, from which we can infer possible allergenicity. This is a preliminary study to screen allergens from the basis of disulfide bonding.