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Toju H.,Kyoto University | Abe H.,Tohoku University | Ueno S.,Japan Forestry and Forest Products Research Institute | Miyazawa Y.,Kyushu University | And 3 more authors.
American Naturalist | Year: 2011

In nature, spatiotemporally dynamic coevolutionary processes play major roles in the foundation and maintenance of biodiversity. Here, we examined the arms race coevolution involving a seed-eating weevil with a long snout and its camellia plant host with a thick fruit coat (pericarp) throughout the marked climatic gradient observed across the Japanese islands. Results demonstrated that female weevils, which bored holes through camellia pericarps to lay eggs into seeds, had evolved much longer snouts than males, especially in areas in which Japanese camellia pericarps were very thick. The thickness of the plant pericarp was heritable, and the camellia plant evolved a significantly thicker pericarp on islands with the weevil than on islands without it. Across populations with weevils, resource allocation to plant defense increased with increasing annual mean temperature or annual precipitation, thereby geographically differentiating the evolutionary and ecological interactions between the two species. Given that the coevolutionary relationship exhibited appreciable variation across a relatively small range of annual mean temperatures, ongoing global climatic change can dramatically alter the coevolutionary process, thereby changing the ecological interaction between these species. © 2011 by The University of Chicago.


Tarutani Y.,Nara Institute of Science and Technology | Tarutani Y.,National Institute of Genetics | Shiba H.,Nara Institute of Science and Technology | Iwano M.,Nara Institute of Science and Technology | And 6 more authors.
Nature | Year: 2010

A diploid organism has two copies of each gene, one inherited from each parent. The expression of two inherited alleles is sometimes biased by the effects known as dominant/recessive relationships, which determine the final phenotype of the organism. To explore the mechanisms underlying these relationships, we have examined the monoallelic expression of S-locus protein 11 genes (SP11), which encode the male determinants of self-incompatibility in Brassica. We previously reported that SP11 expression was monoallelic in some S heterozygotes, and that the promoter regions of recessive SP11 alleles were specifically methylated in the anther tapetum. Here we show that this methylation is controlled by trans-acting small non-coding RNA (sRNA). We identified inverted genomic sequences that were similar to the recessive SP11 promoters in the flanking regions of dominant SP11 alleles. These sequences were specifically expressed in the anther tapetum and processed into 24-nucleotide sRNA, named SP11 methylation inducer (Smi). Introduction of the Smi genomic region into the recessive S homozygotes triggered the methylation of the promoter of recessive SP11 alleles and repressed their transcription. This is an example showing sRNA encoded in the flanking region of a dominant allele acts in trans to induce transcriptional silencing of the recessive allele. Our finding may provide new insights into the widespread monoallelic gene expression systems. © 2010 Macmillan Publishers Limited. All rights reserved.


Okuda M.,National Agriculture Research | Okazaki S.,Forestry and Fisheries Research Center | Yamasaki S.,Forestry and Fisheries Research Center | Okuda S.,National Agriculture Research | Sugiyama M.,National Institute of Vegetable and Tea Science
Phytopathology | Year: 2010

Cucurbit chlorotic yellows virus (CCYV) causes chlorotic yellows on cucumber (Cucumis sativus) and melon (Cucumis melo) and is transmitted by Bemisia tabaci biotype B and Q whiteflies. To characterize the host range of CCYV, 21 cucurbitaceous and 12 other plant species were inoculated using whitefly vectors. All tested Cucumisspp. except Cucumis anguria and Cucumis zeyheri were systemically infected with CCYV, although infection rates varied among species. Citrullus lanatus, Cucurbita pepo, and Luffa cylindrica were susceptible to CCYV; however, the infection rates were low and symptoms were unclear. In addition to the cucurbitaceous plants, Beta vulgaris, Chenopodium amaranticolor, Chenopodium quinoa, Spinacia oleracea, Lactuca sativa, Datura stramonium, and Nicotiana benthamiana were also systemically infected by CCYV. Complete RNA1 and RNA2 were reverse-transcribed, cloned, and sequenced. CCYV RNA1 was found to be 8, 607 nucleotides (nt) long and contained four open reading frames (ORFs). The first ORF spanned methyltransferase and RNA helicase domains followed by an RNA-dependent RNA polymerase domain, presumably translated by a +1 ribosomal frameshift. CCYV RNA2 was found to be 8, 041 nt long and contained eight ORFs, including the hallmark gene array of the family Closteroviridae. Phylogenetic analysis demonstrated that CCYV was genetically close to Lettuce chlorosis virus, Bean yellow disorder virus, and Cucurbit yellow stunting disorder virus. Amino acid sequence similarities of representative proteins with these viruses indicated that CCYV should be classified as a distinct crinivirus species. © 2010 The American Phytopathological Society.


Inaba T.,University of Miyazaki | Yazu F.,University of Miyazaki | Ito-Inaba Y.,University of Miyazaki | Kakizaki T.,National Institute of Vegetable and Tea Science | Nakayama K.,Raffinee International Co.
International Review of Cell and Molecular Biology | Year: 2011

Plastids are a diverse group of organelles found in plants and some parasites. Because genes encoding plastid proteins are divided between the nuclear and plastid genomes, coordinated expression of genes in two separate genomes is indispensable for plastid function. To coordinate nuclear gene expression with the functional or metabolic state of plastids, plant cells have acquired a retrograde signaling pathway from plastid to nucleus, also known as the plastid signaling pathway. To date, several metabolic processes within plastids have been shown to affect the expression of nuclear genes. Recent progress in this field has also revealed that the plastid signaling pathway interacts and shares common components with other intracellular signaling pathways. This review summarizes our current knowledge on retrograde signaling from plastid to nucleus in plant cells and its role in plant growth and development. © 2011 Elsevier Inc.


Okuda S.,Kagoshima University | Okuda M.,Chiyoda Corporation | Sugiyama M.,National Institute of Vegetable and Tea Science | Sakata Y.,National Agriculture Research Center for Kyushu Okinawa Region | And 2 more authors.
European Journal of Plant Pathology | Year: 2013

Fifty-one melon (Cucumis melo) accessions that originated from India, Pakistan and Bangladesh were evaluated for resistance to Cucurbit chlorotic yellows virus (CCYV), a newly emerged species in the genus Crinivirus. CCYV was inoculated using sweet potato whitefly (Bemisia tabaci) biotype Q. Accessions, JP 138332, JP 216154, JP 216155, JP 216751 and JP 91204, showed no or faint symptoms, although CCYV was detected from the non-inoculated upper leaves by reverse transcription-polymerase chain reaction (RT-PCR). The five accessions were subjected to quantitative RT-PCR to analyze relative accumulation of CCYV RNA. All accessions except JP 138332 had levels of CCYV RNA accumulation comparable to the commercial variety, 'Earl's Seine', which was used as a control. JP 138332 showed a much lower CCYV RNA accumulation. Numbers of B. tabaci biotype Q on JP 138332 did not differ from 'Earl's Seine', in antixenosis tests, and the result suggested the resistance to CCYV was not due to antixenosis. Consequently, five accessions are of interest for development of resistant varieties. In particular, JP 138332 possesses a promising resistant trait for CCYV, which might be associated with inhibition of virus multiplication. © 2012 KNPV.


Kakizaki T.,National Institute of Vegetable and Tea Science | Yazu F.,University of Miyazaki | Nakayama K.,University of Miyazaki | Nakayama K.,Raffinee International Co. | And 2 more authors.
Journal of Experimental Botany | Year: 2012

Retrograde signalling from the plastid to the nucleus, also known as plastid signalling, plays a key role in coordinating nuclear gene expression with the functional state of plastids. Inhibitors that cause plastid dysfunction have been suggested to generate specific plastid signals related to their modes of action. However, the molecules involved in plastid signalling remain to be identified. Genetic studies indicate that the plastid-localized pentatricopeptide repeat protein GUN1 mediates signalling under several plastid signalling-related conditions. To elucidate further the nature of plastid signals, investigations were carried out to determine whether different plastid signal-inducing treatments had similar effects on plastids and on nuclear gene expression. It is demonstrated that norflurazon and lincomycin treatments and the plastid protein import2-2 (ppi2-2) mutation, which causes a defect in plastid protein import, all resulted in similar changes at the gene expression level. Furthermore, it was observed that these three treatments resulted in defective RNA editing in plastids. This defect in RNA editing was not a secondary effect of down-regulation of pentatricopeptide repeat protein gene expression in the nucleus. The results indicate that these three treatments, which are known to induce plastid signals, affect RNA editing in plastids, suggesting an unprecedented link between plastid signalling and RNA editing. © 2011 The Author(s).


Kaundun S.S.,Hill International | Kaundun S.S.,National Institute of Vegetable and Tea Science | Matsumoto S.,National Institute of Vegetable and Tea Science
Journal of the Science of Food and Agriculture | Year: 2011

Background: Tea is the most consumed beverage worldwide after water. Yet very little is known about the genetics of tea in comparison with other crop species. Here we have taken advantage of the polymorphic nature of microsatellite DNA to investigate the mode of chloroplast inheritance in tea, Camellia sinensis (L.) O. Kuntze. This is important for the correct interpretation of phylogeny and introgression data as well as assessing the suitability of chloroplast transformation as a means for transgene containment in tea. Results: The study was based on six Japanese tea cultivars, namely Aj2, CK23, Hatsumomiji, Nka05, Yamanoibuki and Kanayamidori used to generate four informative families. The parental pairs in the crosses differed at a single chlroroplast locus with respect to an imperfect microsatellite repeat of 16 nucleotide bases. In agreement with earlier cytological studies, all 61 progeny displayed a cpDNA profile that was consistent with the maternal inheritance of chloroplasts in tea. Conclusions: The data generated here provide the first molecular evidence of the plastid inheritance in tea. However, we suggest that additional families and polymorphic markers be screened for increasing the confidence in the observed maternal inheritance of chloroplasts in this important crop species. © 2011 Society of Chemical Industry.


Kunihisa M.,National Institute of Vegetable and Tea Science
Journal of the Japanese Society for Horticultural Science | Year: 2011

The cultivated strawberry, Fragaria × ananassa (2n = 8x = 56), is an economically important crop in many regions of the world, and many breeding programs are competing to produce new, high-value cultivars. Despite this level of interest, marker-assisted selection of strawberry based on QTL analysis has lagged behind that of diploid crops because of its complex polyploidy and unclear genomic construction. During the past decade, great progress in the development of DNA markers has begun to overcome these difficulties, and the study of inheritance, mapping, and phylogeny is proceeding rapidly. Meanwhile, strawberry breeders have become much more aware of their rights with respect to the cultivars they have developed, as the volumes of harvested fruits that are transported globally have increased. To address the need to identify illegally grown strawberry fruits, genomics researchers have been required to develop simple and reproducible techniques for cultivar identification. This review summarizes the recent development of DNA marker studies in F. × ananassa, with a focus on the genome-specific markers we have developed. JSHS © 2011.


Uesugi R.,National Institute of Vegetable and Tea Science | Sato Y.,National Institute of Vegetable and Tea Science
Japanese Journal of Applied Entomology and Zoology | Year: 2011

The tea-infesting population of Aleurocanthus spiniferus (Quaintance), which has spread to tea gardens in Japan since its discovery in 2004, was differentiated from the citrus-infesting population, which was identified in Japan in 1922, by polymerase chain reaction (PCR) of the mitochondrial cytochrome c oxidase subunit I (mtCOI) gene. Sequences of mtCOI differ between the tea- (assessed in 27 tea gardens in 14 prefectures) and citrus-infesting populations (evaluated in 11 citrus orchards in 8 prefectures); no variations were noted within each population, and the base identity between the populations was 78.0% (674 base pairs). Additionally, individuals from Camellia sasanqua, Eurya japonica, Illicium anisatum, and Zanthoxylum piperitum were identified as belonging to the tea-infesting population and individuals from Caesalpinia crista were identified as belonging to the citrus-infesting population. The 2 populations can be distinguished by PCR with specific primers.


Hirono H.,National Institute of Vegetable and Tea Science
Food Science and Technology Research | Year: 2016

We examined the dynamics of water-soluble pectin (WSP), specifically the content and molecular weight distribution, in tea leaves and tea infusions in relation to steaming time during unrefined tea processing. It was revealed that the fraction of higher-molecular weight (MW) WSP in tea leaves was infused at the beginning of unrefined tea processing at all steaming times, and lower-MW WSP was not infused during any processing steps. Moreover, by increasing steaming time, the increase of higher-MW WSP content in tea leaves was reflected by the increase in WSP content of corresponding size in the tea infusions. © 2016, Japanese Society for Food Science and Technology.

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