SUMMARYThis comprehensive overview of the xyloglucan endotransglucosylase/hydrolase (XTH) family of genes and proteins in bryophytes, based on research using genomic resources that are newly available for the moss Physcomitrella patens, provides new insights into plant evolution. In angiosperms, the XTH genes are found in large multi-gene families, probably reflecting the diverse roles of individual XTHs in various cell types. As there are fewer cell types in P. patens than in angiosperms such as Arabidopsis and rice, it is tempting to deduce that there are fewer XTH family genes in bryophytes. However, the present study unexpectedly identified as many as 32 genes that potentially encode XTH family proteins in the genome of P. patens, constituting a fairly large multi-gene family that is comparable in size with those of Arabidopsis and rice. In situ localization of xyloglucan endotransglucosylase activity in this moss indicates that some P. patens XTH proteins exhibit biochemical functions similar to those found in angiosperms, and that their expression profiles are tissuedependent. However, comparison of structural features of families of XTH genes between P. patens and angiosperms demonstrated the existence of several bryophyte-specific XTH genes with distinct structural and functional features that are not found in angiosperms. These bryophyte-specific XTH genes might have evolved to meet morphological and functional needs specific to the bryophyte. These findings raise interesting questions about the biological implications of the XTH family of proteins in non-seed plants.

Biocontrol agents (BCA) effectively suppress soil-borne disease symptoms using natural antagonistic prokaryotes or eukaryotes. The main issue associated with the application of BCA is that disease reduction effects are unstable under different field conditions. In order to identify potentially effective BCA among several fields, we compared prokaryotic and eukaryotic communities in soil with and without tomato bacterial wilt from three different fields, each of which had the same field management and similar soil characteristics. Soil samples were collected from three fields and two depths because bacterial wilt pathogens were present in soil at a depth greater than 40 cm. We classified soil samples based on the presence or absence of the bacterial phcA gene, a key gene for bacterial wilt pathogenicity and tomato disease symptoms. Pyrosequencing of the prokaryotic 16S rRNA gene and eukaryotic internal transcribed spacer region sequences showed that the diversity and richness of the communities mostly did not correlate with disease symptoms. Prokaryotic and eukaryotic community structures were affected more by regional differences than the appearance of disease. Several prokaryotes and eukaryotes were more abundant in soil that lacked disease symptoms, and eight prokaryotes and one eukaryote of this group were commonly detected among the three fields. Some of these taxa were not previously found in disease-suppressive soil. Our results suggest that several prokaryotes and eukaryotes control plant disease symptoms.

A method for Agrobacterium-mediated transformation of Freesia×hybrida is described. Cormlet-derived calli of two cultivars, 'Mosera' and 'Ishikawa f3' were co-cultivated with Agrobacterium tumefaciens strain EHA105 harboring the binary vector pIG121-Hm, which included hygromycin phosphotransferase gene and an intron-containing β-glucuronidase gene in the T-DNA region. Callus pieces were co-cultivated with A. tumefaciens on the callus proliferation medium [Murashige and Skoog (MS) medium containing 1 mg l −1 thidiazuron, 1 mg l −1 dicamba, 20 mg l −1 3′,5′-dimethoxy-4′-hydroxyacetophenone, 1% (w/v) glucose, 3% (w/v) sucrose, and 0.2% (w/v) Gelrite]. Then, they were cultured on the callus proliferation medium containing 300 mg l −1 cefatoxime and 10 mg l −1 hygromycin B. Hygromycin-resistant lines of both cultivars regenerated into plantlets after transfer onto MS medium containing 2 mg l −1 3-indoleacetic acid and 3 mg l −1 6-benzyl aminopurine and/or plant growth regulator-free MS medium. Transgenic plants were identified by β-glucuronidase assay and verified by Southern blot analysis. Two transgenic plant lines were obtained from 475 callus pieces of 'Mosera' , and one transgenic plant line was obtained from 290 callus pieces of 'Ishikawa f3' . This is the first report of the genetic transformation of Freesia. This method will allow the genetic improvement of this horticulturally important flower.

Crocetin glycosides such as crocin are noted as functional food materials since the preventive effects of crocin have been reported against chronic disease and cancer. However, it is unclear how these apocarotenoids are structurally changed through cooking for our intake. We examined such changes in crocetin glycosides (crocin, tricrocin, and crocin-3) contained in saffron (stigmas of Crocus sativus) through cooking models. These glycosides were almost kept stable in boiling for 20 min (a boiled cooking model), while hydrolysis of the ester linkage between glucose and the crocetin aglycone occurred in a grilled cooking model (180°C, 5 min), along with a 13-cis isomerization reaction in a part of crocetin subsequently generated. We further here revealed that the yellow petals of freesia (Freesia x hybrida) with yellow flowers accumulate two unique crocetin glycosides, which were identified to be crocetin (mono)neapolitanosyl ester and crocetin dineapolitanosyl ester. A similar result as above was obtained on their changes through the cooking models. Utility applications of the freesia flowers as edible flowers are also suggested in this study. Additionally, we evaluated singlet oxygen (1O2)-quenching activities of the crocetin glycosides contained in saffron and freesia, and crocetin and 13-cis crocetin contained in the grilled saffron, indicating that they possessed moderate 1O2-quenching activities (IC50 24–64 μM).