Search

Strain BL24T, isolated from bamboo phyllosphere collected in Coimbatore, India, was studied for taxonomic classification. Cells of the strain were aerobic, Gram-stain-positive, motile, catalase- and oxidase-positive rods and grew on media containing methanol. In 16S rRNA gene sequence analysis, strain BL24Tshowed the highest sequence similarities with Paenibacillus phyllosphaeraeKACC 11473T (97.8 %) and Paenibacillus sacheonensisSY01 (95.1 %). DNA-DNA hybridization with P. phyllosphaerae KACC 11473T, phylogenetically the most closely related species, was 21.6 %; this value showed that strain BL24Tbelonged to a different species. The cell-wall peptidoglycan was found to possess meso-diaminopimelic acid and the G+C content of genomic DNA was 52.1 mol %. It contained menaquinone (MK)-7 as the predominant respiratory quinone and the major cellular fatty acids are C16 : 0, anteiso-C15 : 0, iso-C16 : 0, and anteiso-C17 : 0. Based on the molecular and chemotaxonomic markers and physiological properties, strain BL24T (=NRRL B-51698T=CCM 7577T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillusmethanolicusis proposed.

Key message Not only the first systematic characterization ofCAOgene in bamboo species, but also the first attempt to study the relationship betweenCAOgene expression and bamboo leaf color variation.

In angiosperms, NADPH: protochlorophyllide oxidoreductase (POR) catalyzes the photoreduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the only light-dependent step in chlorophyll biosynthesis. There is a wide variety of gene organization and light- and development-dependent regulatory mechanisms for the POR genes. In this study, a POR homologue, designated PjPORB, was isolated from Pseudosasa japonica cv. Akebonosuji, which is a cultivar of high ornamental value in landscape due to its unique green-white striped leaf phenotype. The full-length PjPORB cDNA was 1567 bp long with a 1185 bp ORF that encoded 394 amino acids. Multiple amino acid sequence alignment showed that the putative PjPORB shared a high similarity to POR homologues from other plant species, and that the cofactor (NADPH)-binding motif and active site motif in particular were highly conserved among all the PORs. Further, PjPORB was overexpressed in Arabidopsis thaliana; and the Pchlide contents of the genetically modified plants were reduced to a larger extent than that of wild type plants, thereby indicating its important role in Pchlide photoreduction. In real-time quantitative RT-PCR analysis, PjPORB was expressed at higher levels in leaf samples than in culms and roots, and showed a first increasing-then decreasing expression pattern during the development of white, stripe, and green leaf samples, thus indicating its essential role in leaf development. Although the mRNA levels for PjPORB did not differ considerably among white, stripe, and green leaf samples within the two almost same earlier developmental stages, its expression levels in the late leaf developmental stage fell into two distinct classes: high expression levels in strip and green leaf samples, and low expression levels in white leaf. Collectively, these expression data suggested that PjPORB may be involved in the leaf color variation for P. japonica cv. Akebonosuji.

Ferulic acid derived from Pseudosasa japonica leaves, which possessed antioxidative potentials with DPPH- (54%) and ABTs- (65%) radical scavenging activities, and lipid-peroxidation inhibitory activity (71%), was orally administered to mice for 12 days in order to investigate its effects on exercise endurance capacity and alterations of antioxidant defense systems. Exhaustive swimming time was increased in the ferulic acid-supplemented group compared with the control group on days 6 and 12 (1.7- and 1.8-fold, respectively). When the mice were exhaustively exercised for 2 consecutive days, a high decrease (53%) was shown in the control group, but no change was found in the ferulic acid-treated group. The administration of ferulic acid significantly protected the depletion of enzymatic- and non enzymatic-antioxidants due to exhaustive exercise. Also, lipid-peroxidation levels decreased in the ferulic acid-treated group compared with the non exercised- and control-groups. These results suggest that ferulic acid from Pseudosasa japonica leaves has a chronic effect on endurance exercise capacity, which is attributed to its ability to ameliorate oxidative stress by improving antioxidant potentials.

An antioxidative compound with effective exercise-enhancing potential was isolated from the ethanolic extract of Pseudosasa japonica leaves. The ethanolic extract was partitioned in the order of hexane, chloroform, ethyl acetate, and water. Of the 4 fractions, the ethyl acetate-fraction (PJE-E) showed profound scavenging activity on superoxide anion- and ABTs cation radicals. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) were conducted to isolate a compound with antioxidative activity on exercise endurance capacity from the PJE-E. The structure of the resulting compound was identified as ferulic acid by 1H/13C nuclear magnetic resonance (NMR). This ferulic acid was orally administered to mice for 18 days and its effect on exercise endurance capacity was investigated using an adjustablecurrent water pool. Compared to the control group, a 1.8 fold increase in swimming time was observed in the ferulic acid-administered mice. Results indicate that ferulic acid from P. japonica leaves might contribute to the potent exercise-enhancing effect.

Spontaneous leaf color variation in bamboo provides the opportunity to study the mechanisms of leaf color formation and the breeding of ornamental bamboos. Despite the fact that many genes are known to be involved in leaf color variation in model plants, molecular mechanisms governing natural leaf color variation in bamboo have remained obscure. This study aimed to identify the genes responsible for the occurrence of such phenomena in bamboo using the suppression subtractive hybridization (SSH) method between green and albino leaves in Pseudosasa japonica f. A total of 1062 and 1004 differentially expressed transcripts were obtained from the forward and reverse SSH libraries, respectively. Subsequently, 59 differentially expressed unigenes with potential roles in leaf color formation, predicted via computational analysis of their functional relevance, were selected for further analysis using qPCR. Ten genes, involved in photosynthesis, plastid development, and cation signal transduction, showed 2-fold changes in expression levels between green and albino leaves. Further expression pattern analyses of these genes at three developmental stages revealed much lower expression abundance of Lhca1-encoded chlorophyll a/b binding protein in the albino leaves than in the green leaves. Our results suggest that, together with the concatenated negative pressure for subsequent photosynthetic processes, the albino phenotype is at least partly attributable to chloroplast inner membrane damage or to the impairment of photosynthetic pigment accumulation, which results from low Lhca1 expression.

The performance-enhancing effects of Pseudosasa japonica were investigated in mice using an adjustable-current water pool. Compared to the control group, a 1.5-fold increase in swimming time was observed in the mouse group administered an 80% ethanol extract (PJE) of the leaves of P. japonica. The blood lactate level, an important indicator of fatigue, was significantly lower (28%, P

Extensive studies have revealed that various kinds of plant leaf have a hydrophobic property which arises from the micro- and nano-scale structure of the leaves. As the self-cleaning capability of plant leaves, termed the lotus effect, is based on their micro- and nano-scale structure, this hydrophobic property can be obtained on various other surfaces by duplication of the leaves' structure. In this study, the hydrophobic structure on bamboo leaves (Pseudosasa japonica) was successfully replicated on a glass substrate using polydimethylsiloxane (PDMS) molding technique and UV nano-imprint lithography. The replicated nano structure, made of perfluorinated acrylate imprint resin, was characterized by scanning electron microscopy (SEM) and its hydrophobicity was evaluated by contact angle measurements which confirmed that the hydrophobic nature and self-cleaning capability of the original bamboo leaves were also replicated.

Summary Leaves of Trachycarpus fortunei from palms growing in warm temperate regions of Europe and Japan as outdoor ornamentals were cooled down to low subfreezing temperatures, and the process of ice formation was followed using differential thermal analysis (DTA). Inactivation of photosynthetic function was determined by in vivo chlorophyll fluorescence, and the progress of injuries during freezing was assayed by viability tests after thawing. Ultrastructure of mesophyll cells was investigated by transmission electron microscopy. Silica incrustation of cell walls was documented by means of qualitative energy dispersive X-ray analysis (EDAX) on samples of Trachycarpus fortunei, Washingtonia filifera, and of the bamboo Pseudosasa japonica. DTA revealed typical freezing patterns, with a high temperature exotherm at about -6 to -8°C and a broad low temperature exotherm rising from about -13 to -14°C. As soon as the tissues froze, characteristic changes appeared in the kinetics of in vivo fluorescence. No irreversible inactivation of photosynthesis or damage was detectable at temperatures above appearance of the low exotherm. Within a short time after attainment of the exotherm peak, the leaf segments were found to be lethally damaged. Both of in vivo fluorescence and viability tests clearly indicated that Trachycarpus leaves remain in the persistent supercooled state down to quite low temperatures. The tensile state of water at threshold supercooling temperatures of Trachycarpus leaves was calculated according to the equation of Rajashekar and Burke (1982) and found to be about -14 MPa. An explanation for the permanent maintenance of such a large displacement from thermodynamic equilibrium could be that silica incrustation, as revealed by EDXA, favours supercooling by increasing the rigidity of the cell walls and/or resistance to the growth of ice crystals.