JOURNAL

Contents

Preface

Targeted mutation breeding of flower color by taking advantage of ion-beam irradiation and genomic information

Atsushi Tanaka. . . . . . . 191 [PDF]

Review

Development of an efficient mutagenesis technique using ion beams: Toward more controlled mutation breeding

Yoshihiro Hase, Yusuke Akita, Satoshi Kitamura, Issay Narumi, Atsushi Tanaka. . . . . . . 193 [PDF]

Ion beams have been used as a mutagen to improve the efficiency of plant mutation breeding. In this review, we describe our recent progress in developing a more efficient mutagenesis technique using ion beam irradiation combined with sucrose pretreatment or subsequent reirradiation. To shorten the time required for breeding new cultivars of cyclamen, we identified anthocyanin biosynthesis genes and examined the effectiveness of PCR screening of irradiated deletionmutant candidates at early growth stages.

Production of novel flower color mutants from the fragrant cyclamen (Cyclamen persicum × C. purpurascens) by ion-beam irradiation

Hiroshi Ishizaka, Emiko Kondo, Naoko Kameari. . . . . . . 201 [PDF]

In order to create novel flower colors of fragrant cyclamen (Cyclamen persicum × C. purpurascens), mutation breeding was carried out by ion-beam irradiation combined with plant tissue culture technique. The flower color and pigment of the original plant and the mutant were discussed in relation to a flavonoid biosynthetic pathway.

Breeding glittering carnations by an efficient mutagenesis system

Masachika Okamura, Naoyuki Umemoto, Noboru Onishi. . . . . . . 209 [PDF]

We have developed a systematic and directed method to create novel glittering mutants in carnation (Dianthus caryophyllus) consisting of strategy to select appropriate genotypes for specific breeding aims using genomic information, identifying factors that induce anthocyanic vacuolar inclusions (AVIs), and consecutive ion-beam irradiation to modify pigment glycosylation and/or acylation. We analyzed the content of anthocyanins and related compounds in the flowers of these mutants.

Comprehensive analyses of anthocyanin and related compounds to understand flower color change in ion-beam mutants of cyclamen (Cyclamen spp.) and carnation (Dianthus caryophyllus)

Masayoshi Nakayama, Natsu Tanikawa, Yasumasa Morita, Yusuke Ban. . . . . . . 215 [PDF]

We analyzed anthocyanin and its biosynthetically related compounds in flower color mutants of cyclamen and carnation obtained by ion-beam to lead to following ideas: biosyntheses of these compounds are cooperatively and compensatively regulated; multiple factors are often concerned in generation of one coloration phenotypes; and structural changes of a pigment influence the physical, chemical and physicochemical properties to generate novel coloration.

Short Communication

Identification of the glutathione S-transferase gene responsible for flower color intensity in carnations

Nobuhiro Sasaki, Yuzo Nishizaki, Yasuhiro Uchida, Eigo Wakamatsu, Naoyuki Umemoto, Masaki Momose, Masachika Okamura, Hiroyuki Yoshida, Masaatsu Yamaguchi, Masayoshi Nakayama, Yoshihiro Ozeki, Yoshio Itoh. . . . . . . 223 [PDF]

Two cDNAs (DcGSTF1 and DcGSTF2) with homology to glutathione S-transferase (GST) were isolated from the carnation (Dianthus caryophyllus). A truncated DcGSTF2 gene, resulting from the insertion of a CACTA-type transposable element, was found in the genome of a mutable flower line bearing deep pink sectors on pale pink petals. 35S-DcGSTF2 was introduced into the epidermal cells of carnations bearing pale pink petals by particle bombardment. The transformed cells showed deep pink color. These results suggest that the DcGSTF2 gene is responsible for flower color intensity in carnations.

Original Papers

Overexpression of the tomato glutamate receptor-like genes SlGLR1.1 and SlGLR3.5 hinders Ca2+ utilization and promotes hypersensitivity to Na+ and K+ stresses.

Asma Aouini, Michel Hernould, Tohru Ariizumi, Chiaki Matsukura, Hiroshi Ezura, Erika Asamizu. . . . . . . 229 [PDF] [Supplement]

We overexpressed two tomato glutamate receptor-like genes, SlGLR1.1 and SlGLR3.5, in Arabidopsis to observe phenotypes with regard to Ca2+ uptake and sensitivity to K+ and Na+ stresses. The results indicated that the overexpression did not affect Ca2+ uptake. Transgenic lines were hypersensitive to K+ and Na+ ionic stresses, which was rescued by addition of Ca2+ to the growth medium. These results suggested that these genes might play a role in calcium assimilation in tomato by controlling ionic transport across the membrane.

Evaluation of some therapies and meristem culture to eliminate Potato Y potyvirus from infected potato plants

K. AlMaarri, R. Massa, F. AlBiski. . . . . . . 237 [PDF]

Several techniques were tested to PVY virus elimination in Potato. The rate of PVY elimination was improved after treatment by thermotherapy, Chemotherapy and Electrotherapy. The highest percentage of PVY virus free plantlets (93% in Binella and 87% in Burren) were obtained from meristem-tips 100µm in length excised after electric treatments(15 mA /10 min).

Overexpression of Q/q-related homoeoalleles of hexaploid wheat reveals distinct recovery of flower transformation in the apetala2 mutant of Arabidopsis.

Parisa Abdollahi, Yoko Kamiya1, Kanako Kawaura, Yasunari Ogihara. . . . . . . 245 [PDF]

The Q gene which encodes APET ALA2-like transcription factor WAP2AQ, has played substantial roles in wheat domestication. Its allele WAP2Aq, and homoeoallele WAP2D along with WAP2AQ showed typical ear morphology. We overexpressed these three genes in the ap2 mutant of Arabidopsis, and used a yeast 2-hybrid system to examine homodimer formation ability. Three genes revealed typical flower recoveries, and homodimer formation abilities. The results were discussed in relation to gene functions.

SlICE1 encoding a MYC-type transcription factor controls cold tolerance in tomato, Solanum lycopersicum.

Kenji Miura, Hayato Shiba, Masaru Ohta, Seung Won Kang, Ayaka Sato, Takashi Yuasa, Mari Iwaya-Inoue, Hiroshi Kamada, Hiroshi Ezura. . . . . . . 253 [PDF]

We characterized a basic helix-loop-helix transcription factor, SlICE1, in tomatoes, Solanum lycopersicum. SlICE1 shows similarity with Arabidopsis ICE1 and overexpression of SlICE1 enhanced expression of cold-regulated genes, accumulation of ascorbic acid, and chilling tolerance in tomato plants. These results indicate that SlICE1 plays an important role in regulation of cold tolerance in tomatoes.

Accumulation of antioxidants and antioxidant activity in tomato, Solanum lycopersicum, are enhanced by the transcription factor SlICE1.

Kenji Miura, Ayaka Sato, Hayato Shiba, Seung Won Kang, Hiroshi Kamada, Hiroshi Ezura. . . . . . . 261 [PDF] [Supplement]

SlICE1 plays an important role in the accumulation of antioxidants and in the regulation of antioxidant activity in tomato red fruits. Overexpression of SlICE1 in tomatoes enhanced the accumulation of antioxidants, such as β-carotene, lycopene, and ascorbic acid. Metabolite profiling analysis revealed that sugars, several amino acids, and amines were also highly accumulated in SlICE1-overexpressing tomato red fruits.

Establishment of a novel system to elucidate the mechanisms underlying light-induced ripening of strawberry fruit with an Agrobacterium-mediated RNAi technique.

Katsuyuki Miyawaki, Sachi Fukuoka, Yasuko Kadomura, Hirokazu Hamaoka, Taro Mito, Hideyo Ohuchi, Wilfried Schwab, Sumihare Noji. . . . . . . 271 [PDF] [Supplement]

In this study, we developed a light-induced ripening system with post-harvest strawberry fruit Fragaria × ananassa cv. Sachinoka through the expression analysis of anthocyanin synthetic genes such as CHS and F3’H, and established a protocol to effectively elucidate fruit ripening mechanisms using an Agrobacterium-mediated RNAi (AmRNAi) technique in a small artificial environment.

Sugar-inducible RPT2a, a subunit of 26S proteasome, participates in sugar response in Arabidopsis.

Huihui Sun, Kaori Sako, Yuya Suzuki, Shugo Maekawa, Shigetaka Yasuda, Yukako Chiba, Takeo Sato, Junji Yamaguchi. . . . . . . 279 [PDF] [Supplement]

The ubiquitin/26S proteasome system plays a central role in the degradation of short-lived regulatory proteins that control many cellular events. In this study, the Arabidopsis knockout mutant rpt2a, which contains a defect in the AtRPT2a subunit of the 26S proteasome regulatory particle, showed hypersensitivity to sugars as well as enlarged leaves. These findings indicate that AtRPT2a plays an essential role in the maintenance of proteasome-dependent proteolysis activity in response to sugars.

Transgenic Petunia hybrida expressing a synthetic fungal chitinase gene confers disease tolerance to Botrytis cinerea.

Raham Sher Khan, Nanako Kameya, Masahiro Mii, Ikuo Nakamura. . . . . . . 285 [PDF]

Synthetic chitinase (NIC) gene designed based on chi1 gene of Rhizopus oligosporus was introduced into genome of Petunia hybrida through Agrobacterium-mediated transformation. The NIC gene encoded identical amino acid sequence with the chi1 gene, except two amino acids, but 18% of codons in the gene were changed from fungal-type codon usage to plant-type. Fungal growth assay using detached leaves or leaf extracts from the transgenic petunia showed enhance resistance against Botrytis cinerea.

Short Communication

Isolation and characterization of asparagines-rich protein that regulates hypersensitive cell death-mediated resistance in Nicotiana plants.

Daisuke Komori, Masahiro Nishihara, Akiko Takahashi, Meenu Gupta, Hirofumi Yoshioka, Hiroyuki Mizumoto, Kouhei Ohnishi, Yusufumi Hikichi, Akinori Kiba. . . . . . . 293 [PDF] [Supplement]

Induction of HR was delayed in NbARP-silenced plants challenged with incompatible R. solanacearum 8107, Pseudomonas cichorii and P. syringae pv. Syringae, and Agrobacterium-expressing HR inducers. Several defense-related responses were reduced in NbARP-silenced plants. Growth of R. solanacearum 8107 was accelerated in NbARP-silenced plants, whereas the bacterial growth was decreased in NbARP-overexpressing plants. These results suggest that NbARP is closely related to the HR.

Responses to flooding stress in soybean seedlings with the alcohol dehydrogenase transgene.

Makoto Tougou, Akiko Hashiguchi, Kiyoshi Yukawa, Yohei Nanjo, Susumu Hiraga, Takuji Nakamura, Keito Nishizawa, Setsuko Komatsu. . . . . . . 301 [PDF]

The soybean is sensitive to flooding. We introduced the soybean alcohol dehydrogenase (GmAdh2) gene under the control of a constitutive promoter to soybeans and subjected the soybeans to flooding stress. The first acquired line of transgenic soybean seedlings germinated vigorously relative to control soybeans after flooding. Our experiments indicated that the introduced GmAdh2 gene might have improved the germination of transgenic soybeans under flooding stress.

Improvement of the plastid transformation protocol by modifying tissue treatment at pre- and post-bombardment in tobacco.

Ayako Okuzaki, Yutaka Tabei. . . . . . . 307 [PDF]

We improved plastid transformation protocol by modifying leaf tissue treatment in order to decrease drought stress and damage due to cutting before selection culture. Modifying tissue treatment improved the efficiency and stability of plastid transformation. This finding should aid plastid transformant production in tobacco and other plant species.

Somatic embryogenesis in leaf tissue culture of Soapberry (Sapindus mukorossi Gaertn.)

Hyun-Tae Kim, Byeung-Hoon Yang, Young Goo Park, Jang R. Liu. . . . . . . 311 [PDF]

Leaf explants excised from seedlings of soapberry (Sapindus mukorossi Gaertn.) formed embryogenic calluses at a frequency of 53.9% when cultured on B5 media supplemented with 0.1mgl−1 2, dichlorophenoxyacetic acid (2, 4-D) and 0.01mgl−1 6-benzyladenine (BA) for 6 weeks. Upon transfer onto media with 5mgl−1 abscisic acid, embryogenic calluses yielded somatic embryos at 73%. Somatic embryos developed into plantlets on media without plant growth regulators at 90%. Embryogenic calluses proliferated and maintained embryogenic capacity when subcultured on media with 0.1mgl−1 2, D and 0.01mgl−1 BA at 4-week intervals. This culture system is an effective means for clonal propagation and genetic manipulation of soapberry because it ensures taproot development required for tree stability.

Notes

Modification of light quality improves the growth and medicinal quality of clonal plantlet derived from the herbal plant Gentiana.

Hideyuki Takahashi, Hidetoshi Yamada, Chiharu Yoshida, Tomohiro Imamura. . . . . . . 315 [PDF]

In this study, we propose in vitro clonal cultures of plantlets derived from gentians (Gentiana triflora and G. scabra) are suitable for used as herbal medicines. We found that the plantlets contained active components and irradiation with specific wavelength of LED light improved the growth and active component concentrations in the plantlets, suggesting that the gentian plantlets can be used as an ingredient in natural medicine.

High level expression of transgenes by use of 5′-untranslated region of the Arabidopsis thaliana arabinogalactan-protein 21 gene in dicotyledons.

Takeshi Matsui, Hideyuki Matsuura, Kazutoshi Sawada, Eiji Takita, Satoko Kinjo, Shinya Takenami, Kiyotaka Ueda, Naoya Nishigaki, Shotaro Yamasaki, Kensuke Hata, Masatoshi Yamaguchi, Taku Demura, Ko Kato. . . . . . . 319 [PDF] [Supplement]

In this study, thirty nine 5′-UTRs derived from Arabidopsis thaliana genes were tested by transient expression of firefly luciferase, and that of arabinogalactan-protein 21 gene was selected for further analyses. Its activity was either equaling or surpassing that of known translational enhancer, A.thaliana alchol dehydrogenase 5′-UTR in dicotyledons, and was further improved by the optimizing sequence context of the initiating codon (-3 to -1 of AUG).