Production of biobased functional polymers from woody biomass is becoming increasingly important for biorefineries. We studied the direct production of vanillin and vanillic acid, which are key monomer components for thermostable polymers, from a softwood Japanese cedar by an alkaline copper oxide−peroxide reaction using microwave (MW) and conventional heating (CH) reactors. MW heating at 180 °C for 10 min produced vanillin and vanillic acid in yields nearly three times higher than those produced by conventional heating (10.1% vs 3.4%). The MW and CH experiments were precisely compared using the same heating conditions and the same reaction vessel. A cavity resonator (single-mode microwave) which can separate electric (E) and magnetic (H) fields were used for wood degradation. The results revealed that the reactions were accelerated by both fields with a slightly more prominent effect of electric fields (E max ). The activation energy of experiments under CH, MW-E max , and MW-H max was calculated. The yield enhancement and decrease of activation energy unequivocally indicate the MW-sensitive character of this reaction. When hardwood (Eucalyptus globulus) was used as a feedstock, syringaldehyde and syringic acid were produced together with vanillin and vanillic acid, and the maximum yield of the monomers reached 11.4% based on the original wood weight under MW heating. This method was successfully scaled up by using a 1-L scale MW reactor to give vanillin and vanillic acid at a total yield of 8.5%.

Juvenile-to-adult phase change is an indispensable event which guarantees a successful life cycle. Phase change has been studied in maize, Arabidopsis and rice, but is mostly unknown in other species. Soybean/Fabaceae plants undergo drastic changes of shoot architecture at the early vegetative stage including phyllotactic change and leaf type alteration from simple to compound. These characteristics make soybean/Fabaceae plants an interesting taxon for investigating vegetative phase change. Following the expansion of two cotyledons, two simple leaves simultaneously emerge in opposite phyllotaxy. The phyllotaxy of the third and fourth leaves is not fixed; both opposite and distichous phyllotaxis are observed within the same population. Leaves were compound from the third leaf. But the third leaf was rarely simple. Morphological and quantitative changes in early vegetative phase were recognized in leaf size, leaf shape, number of trichomes, stipule size and shape, and shoot meristem shape. Two microRNA genes, miR156 and miR172, are known to be associated with vegetative phase change. Examination of the expression level revealed that miR156 expression was high in the first two leaves and subsequently down-regulated, and that of miR172 showed the inverse expression pattern. These expression patterns coincided with the case of other species. Taken all data together, the first and second leaves represent juvenile phase, the fifth and upper leaves adult phase, and the third and fourth leaves intermediate stage. Further investigation of soybean phase change would give fruitful understandings on plant development.

Gentian is an important ornamental flower in Japan. The corolla of the majority of cultivated Japanese gentians have green spots, which are rarely encountered in flowers of other angiosperms. Little information is available on the functional traits of the green spots. In this study, we characterized the green spots in the Japanese gentian corolla using a number of microscopic techniques. Opto-digital microscopy revealed that a single visible green spot is composed of approximately 100 epidermal cells. The epidermal cells of a green spot formed a dome-like structure and the cell lumen contained many green structures that were granular and approximately 5 μm in diameter. The green structures emitted red autofluorescence when irradiated with 488 nm excitation light. Transmission electron microscopy revealed that the green structures contained typical thylakoids and grana, thus indicating they are chloroplasts. No grana were observed and the thylakoids had collapsed in the plastids of epidermal cells surrounding green spots. To estimate the rate of photosynthetic electron transfer of the green spots, we measured chlorophyll fluorescence using the MICROSCOPY version of an Imaging-PAM (pulse-amplitude-modulated) fluorometer. Under actinic light of 449 μmol m −2 s −1 , substantial electron flow through photosystem II was observed. Observation of green spot formation during corolla development revealed that immature green spots formed at an early bud stage and developed to maturity associated with chloroplast degradation in the surrounding epidermal cells. These results confirmed that the Japanese gentian corolla contains functional chloroplasts in restricted areas of epidermal cells and indicated that a sophisticated program for differential regulation of chloroplast formation and degradation is operative in the epidermis.

Plants develop juvenile phase to adult phase in vegetative stage. Although soybean is a very important crop worldwide, there has been only one study of the juvenile–adult phase change. In this study, we determined that the juvenile–adult phase change occurred at different stages in two soybean cultivars that differ in their photosensitivity. Cultivar ‘Enrei’ (E1e2e3E4) is weakly photosensitive and cultivar ‘Peking’ (E1E2E3E4) is strongly photosensitive. In ‘Enrei’, the leaf size gradually increased at a constant leaf position regardless of the difference in day length. In ‘Peking’ plants transferred to short‐day conditions at several leaf development stages, leaf size gradually increased at different leaf positions. Expression of miR156 by ‘Enrei’ transferred to short‐day conditions had nearly the same pattern as that of ‘Enrei’ grown under long‐day conditions. In ‘Peking’, the expression of miR156 had different patterns in younger leaves of plants subjected to either a short‐day treatment or long‐day conditions. These results indicate that the E2 and E3 loci that regulate photosensitivity also regulate the expression of miR156 and the juvenile–adult phase change in soybean.