Increasing plant resistance against powdery mildew by overexpression of active form of ARA6
Powdery mildew is a popular disease caused by ascomycete fungi. As this disease affects near 10,000 plants and causes significant economic loss every year, a development of new tools to combat this disease is of great interest. In this issue, Inada et al. reported that overexpression of the active form of ARA6, a plant-specific member of RAB5 GTPase, impairs powdery mildew proliferation. Powdery mildew fungi form specialized infection hyphae called the haustorium in the apoplast of host epidermal cells. The haustorium is surrounded by the host-derived membrane called the extrahaustorial membrane. Previously, authors reported that host RAB5 GTPases, both plant-specific ARA6 and conventional ARA7, localized to the extrahaustorial membrane. In this issue, authors found that an overexpression of active form of ARA6, but not that of ARA7, suppresses powdery mildew proliferation. These results indicate a specific role of ARA6 in the plant-powdery mildew interaction. In addition, manipulation of the ARA6 activity was suggested to be a possible methodology to overcome this disease.

Photographed by Noriko Inada (Nara Institute of Science and Technology, NAIST) in NAIST, Japan, 2012 (Panasonic DMC-FX30).
Secretory cavities of Japanese pepper
Japanese pepper (Zanthoxylum piperitum), “Sansho” in Japanese, is a deciduous shrub, belonging to the family Rutaceae. In Japan, fresh young leaves are sometimes used as garnish and in sauces after mixed with miso (soybean paste) for some Japanese dishes because of its characteristic aroma. The fruits exhibit pungent taste together with strong aroma, and are also utilized as one of the seven components of Japanese blended spices called “Shichimi”. Oil secretory cavities are found at all sinuses of leaves, as shown in this photograph, as well as the surface of fruits and contain high amount of volatile compounds. The grade of Japanese pepper is sometimes determined according to the flavor of high quality of volatile mono- and sesqui-terpenes. In this issue, Fujita et al. have reported the formation of volatile terpenes and their biosynthetic enzymes in secretory cavities of Japanese pepper.

Photographed by Mitsuhiro Aida (Nara Institute of Science and Technology, NAIST) in NAIST, Japan, 2015 (ECLIPSE Ni-U microscope equipped with DIC optics, Nikon; VB-7010 cooled CCD camera, Keyence).
Homeotic floral organ changes of transgenic apple
Apple cultivars with homeotic changes, petals to sepals and stamens to carpels, set parthenocarpic fruits. The floral organ changes were caused by destruction of apple MdPISTILLATA (MdPI) gene, which is an orthologue of Arabidopsis class B gene PISTILLATA. The MdPI gene is able to recover the Arabidopsis pi mutant phenotype. The expression of MdPI localized at petals and stamens of apple flowers. The connection between the parthenocarpy and class B mutation was obscure, then transgenic apples suppressed MdPI function was produced. The cover picture represents a flower of antisense MdPI transgenic apple, which was analyzed about parthenocarpy in this article (pp. 395–401).

Location: Division of apple Research (Morioka), NIFTS, NARO
Camera: Olympus SP-350
Adaptive environmental responses of plants in synecoculture fields
Synecoculture is based on high-density mixed polyculture, which harbors a wide variety of edible plants and rich interactions between environment, flora and fauna: Leaf color change of no-fertilizer cabbage during winter. Tomato in Tokyo can extend its growth until december crawling over chestnut. Cruciferous vegetables (Brassicaceae) easily intercross and produce hybrid varieties with higher yield. Honey bees and butterflies are not only pollinators but also important enhancers of micronutrients profile of crops. Growth in various association of plants augments productivity of community, and enhanced ecological interactions stimulate the expression of health beneficial components such as secondary metabolites. The cooccurrence networks of relevant species from field observation are superimposed.

Location: Synecoculture fields in Ise (Mie), Oiso (Kanagawa) and Todoroki (Tokyo)
Camera: Panasonic DMC-LX5, Olympus TG-3
Cuticular nanoridges formation in floral organs
Floral organs are decorated by cuticle with nano-order structure called “nanoridges”, although leaves are covered by plane cuticle. Regulation of cuticle structure and thickness is important for stress tolerance to biotic and abiotic stress, plant growth and petal structural color. In this issue, Oshima and Mitsuda report that the expression of MIXTA-like MYB transcription factors using the promoters of cuticle biosynthesis genes successfully increased accumulation of cuticle in leaves and petals without growth defects in Arabidopsis thaliana (pp. 161–168). Increased nanoridges and ectopic outgrowth of epidermal cell of petal abaxial side, stamen and sepal (from top to bottom rows) in transgenic lines (middle and right columns) compared to those in wild type (left column) affected petal texture.

Photographed by Yoshimi Oshima (National Institute of Advanced Industrial Science and Technology, AIST) in AIST, Japan, 2015 (SEM, KEYENCE VE8800; stereomicroscopic camera, ZEISS AxioCam MRc5)
A transcriptomic analysis among max2, hxk1 and wild type seedlings in response to glucose
Strigolactones (SL) are plant hormone that play vital roles in plant architecture. Sugars have been known as important signal molecules to regulate plant growth and development. In this study (pp. 87–97), we found that SL mutants show hyposensitivity to sugar-induced early seedling development arrest. We performed a comparative transcriptomic analysis of max2, hxk1 and wild type (WT) seedlings grown with 2% glucose (G) or mannitol (C) as control. As shown in the figure, several groups of genes show different expression patterns among max2, hxk1 and WT in responses to glucose. These results indicate that SL signal shows crosstalk with sugar signal in HXK1 independent manner.

The transcriptomic data were obtained by short-read sequencing technology (Illumina) combined with a tag-based digital gene expression (DGE) system and analyzed by Pheatmap in R language program.
Agrobacterium-mediated transformation of switchgrass
Switchgrass (Panicum virgatum L.) is an important bioenergy crop. A reliable and efficient transformation method is required to assist with molecular breeding of this crop. After cocultivation with Agrobacterium under optimized conditions, caryopsis-derived Type I (embryogenic and compact) calli formed herbicide-resistant calli (1st row), which showed GFP-fluorescence (2nd row), and then regenerated transgenic shoots (3rd row). The present method was successfully applied to dierent genotypes, including a major lowland cultivar ‘Alamo’ (left), another lowland cultivar ‘Kanlow’ (middle) and a recalcitrant upland cultivar ‘Trailblazer’ (right) (pp. 19–26).

Photographed by Yoichi Ogawa (Honda Research Institute Japan) at Kazusa Unit (Kisarazu, Japan).
PEPCK promotes seedling growth in tomato
Phosphoenolpyruvate carboxykinase (PEPCK) is known as a key regulatory enzyme in the gluconeogenesis pathway in plants. However, its physiological function in whole plant development is not fully understood in plants with fresh berry-type fruit, including tomato.
In this study, in order to obtain more detailed information on the physiological function of PEPCK and the role of gluconeogenesis during development of tomato plant, we generated transgenic tomato plants overexpressing SlPEPCK gene and performed a detailed characterization of those plants. The results indicate multiple roles of PEPCK in the development of the tomato plant, especially in seedling growth, and the effect of the gluconeogenesis pathway on regulation of the sugar and organic acid contents in the fruit.

Photographed by Yong-Xing Huang (University of Tsukuba) in Tsukuba, Japan, 15 and 19 June, 2015.
‘Pinot Noir’ grape berries before and after ripening
‘Pinot Noir’ is a famous cultivar of grape (Vitis vinifera L.) for vine production. Grape accumulates important secondary metabolites, such as anthocyanin, tannin and resveratrol, in berry skin. The turning point of ripening of grape berry is called “veraison.” After veraison, properties of berry, including sugar and acid contents, color and firmness, change dramatically. In this issue, Suzuki et al. report the comparison of metabolomes of berry skin of ‘Pinot Noir’ before and aer veraison (pp.267-272).

Photographed by Katsuhiro Shiratake, Mami Suzuki and Masaki Ochiai (Nagoya University) in Azumino, Nagano, Japan, 23 July and 16 September 2010 (Canon EOS Kiss Digital N, Tamron SP 17–50 mm F/2.8 Di II) and 4 Augusta 2011 (Olympus E-620, Olympus Zuiko Digital ED 50 mm F2.0 Macro).
Color Modified Flowers by Anthocyanin Methyltransferase
The structures of B-ring of anthocyanins are known to change flower color greatly. The effect of 3'- and 5'-methoxylation of anthocyanins in flower color was studied by expressing S-adenosylmethionine: anthocyanin 3',5'-O-methyltranferase (A3'5'OMT) gene from torenia in plants (pp. 109–117). he transgenic Nierembergia petals produced 3'- and 5'-methoxylated anthocyanins based on petunidin and malvidin in petals (the upper picture, the host flower is shown at the top). The paler color of the transgenics were due to the decrease of anthocyanin amount. Expression of a flavonoid 3',5'-hydroxylase gene in a rose cultivar (the lower picture, left) resulted in delphinidin production and magenta color (center). Additional expression of the A3'5'OMT gene yielded more brilliant and attractive color (right) derived from malvidin accumulation than delphinidin alone. hese results indicate that the A3'5'OMT gene is a useful molecular tool to increase the varieties of flower color.

Nierembergia and roses were photographed by Noriko Nakamura (Suntory Global Innovation Center Ltd.) and Yukihisa Katsumoto (Suntory Global Innovation Center Ltd.), respectively, at Suntory Research Center (Osaka).
Effectiveness of CO2 Gas Feeding
Carbon fixation in the leaves and translocation to the fruits are the most fundamental functions for fruit productivity. In this issue, Yamazaki et al. report immediate and different responses of carbon fixation and translocation to enriched external CO2 concentrations in the same individuals of tomato (Solanum lycopersicum L. cv. ‘Micro-Tom’), by visualizing the movement of pulse-fed 11CO2 tracer in the test plants using a positron-emitting tracer imaging system (PETIS) (pp 31–37). Top: 400 ppm CO2. Middle: 1,500 ppm CO2. Bottom: 3,000 ppm CO2.
Bloom of Empress Tree
Paulownia tomentosa (empress tree), or Kiri in Japanese, is a fast-growing tree native to China in the family Paulowniaceae, producing tubular light-purple flowers. In Japan, the plant is adapted as a floral motif for a traditional emblem Kiri mon, or Paulownia crest, of which use by a Sengoku-era warlord Hideyoshi Toyotomi and also today by government (cabinet office) of Japan is known well. Including P. tomentosa, a number of species in the genera Paulownia, Sesamum (Pedaliaceae), and Phryma (Phrymaceae), all belonging to the order Lamiales, are known to produce specialized lignans of furofran type with methylenedioxy bridge, represented by sesamin from sesame seeds. In this issue, Noguchi et al. report that the formation of the methylenedioxy bridge is catalyzed by a conserved cytochrome P450 enzyme in the lignan-producing species (pp 493–504).

Photographed by Eiichiro Ono (Suntory Global Innovation Center Ltd.) in Hanamaki, Iwate, Japan, in spring, 2014 (SONY RX-100).
Christmas illumination in early winter
In Japan, Christmas illumination is common during winter and a variety of natural and artificial plants are decorated with colorful lights. In this issue, Sasaki et al. in National Agriculture and Food Research Organization (NARO) Institute of Floricultural Science (NIFS) have reported a generation of fluorescent Torenia flowers by combination of the highperformance fluorescent protein and the latest protein expression technologies (pp. 309–318). Their work may lead to a use of the fluorescent plants for Christmas illumination in the near future.

Photographed by Tsuyoshi Mizoguchi (International Christian University, ICU) in ICU, Japan, 5 Dec, 2014 (Ricoh GXR, Leica Super Angulon f4/21 mm).
Fruits of Citrus unshiu in mid autumn
In Japan, fruits of Citrus unshiu usually grow larger during summer and the color turns from green to orange in late autumn. e fruits are rich with the yellow pigment, -cryptoxanthin. -cryptoxanthin is a xanthophyll and possesses pro-vitamin A activity for mammals. In plants, xanthophyll cycles play important roles in the protection of photosynthetic apparatus from light-induced oxidative damage. In this issue, Kawabata & Takeda from Osaka Prefecture University report the eect of intense light on the pool size of the xanthophyll cycle in Arabidopsis thaliana (pp. 229–240).

Photographed by Tsuyoshi Mizoguchi (International Christian University, ICU) in ICU, Japan, 5 Sep, 2014 (Ricoh GXR, Leica Summicron f2/35 mm).
Flowers of Hydrangea macrophylla
Most parts of Japan experience a rainy season in early summer, usually from the beginning of June to mid July. Japanese hydrangea (Hydrangea macrophylla) blooms in June and the ower is one of the symbols of the rainy season in Japan. There is a dramatic change in humidity, from wet to dry condition, between the rainy season and mid summer in Japan. Most plants have the ability to adapt to such changes. Molecular mechanisms underlying the tolerance to the dry condition after the rainy season have not been fully understood. In this issue, Watanabe et al. in Hiroshima University have reported roles of purine metabolites in drought stress responses in Arabidopsis thaliana (pp. 173–178).

Photographed by Tsuyoshi Mizoguchi (International Christian University, ICU) in ICU, Japan, 30 May, 2014 (Ricoh GXR P10).
Flowers of Japanese apricot (Prunus mume)
We had record snowfalls over the last two weekends. Heavy snow in Tokyo damaged small plants and big trees alike including cherry and plum trees in Mitaka. There is a famous proverb “The fools who cut cherry trees, the fools who don’t cut plum trees.” Some plants including cherry trees are badly damaged by cutting and wounding. By contrast, other fruit trees including plum often require trimming for better growth. Molecular mechanisms underlying the tissue reunion occurring after the cutting and wounding have not been elucidated.In this issue, Pitaksaringkarn et al. in University of Tsukuba have reported a pivotal role of ARF6 and ARF8 of Arabidopsis thaliana in the tissue reunion process (pp. 49–53).

Photographed by Tsuyoshi Mizoguchi (International Christian University, ICU)
in ICU, Japan, 21 February, 2014 (Ricoh GXR P10).
Dimorphism in shoot
Juniperus chinesis is a very tough conifer tree. This species is easy to grow, has dense branches and has been propagated for making live fences of gardens in Japan. But trees of this species sometimes show unexpected changes in shoot morphology after triming. As shown in the center of this photograph, some shoots show vigorous growth and make spiny leaves, while shoots of this species usually make slow-growing branches with small, round, and densely arranged scaly leaves. Due to their vigorous growth, once they appear, the spiny type of shoots are not easy to control, which makes it difficult to maintain the beauty of the whole tree shape. Skills of gardeners is judged based on whether they can control this or not. This phenomenon is also interesting from viewpoint of switching between two types of organogenesis in shoot.

Photographed by Hirokazu Tsukaya (Univ. Tokyo) in Kamakura, Japan, 27 September, 2012
(Pentax Optio W80).
Drunken flower
“Sui-fuyo” or Drunken Fuyo Hybiscus (Confederate rose) is a mutant of Hibiscus mutabilis L. (“Fuyo” in Japanese) that originally occurs in China. It has been widely cultivated in gardens in Japan as an easy-growing bush tree bearing many pink flowers even under the harsh summer high temperatures. There are two types of “Sui-fuyo”: a basic type with five petals and a double-flowered type. Both are characterized with a late pigmentation: the flower color is white just after the anthesis in the morning, and is gradually turned into pink or red in the midday to the evening. While wild-type flowers complete the synthesis of pink pigments before anthesis, the Sui-fuyo cannot start making pigments before the anthesis. We liken this gradual change in the flower's color to a blush of a young women's face after drinking Sake.

Photographed by Hirokazu Tsukaya (Univ. Tokyo) in Kamakura, Japan, 26 September, 2012 (Pentax Optio W80).
Left: Commercial tomato fruits with high sugar content which is popular in Japanese tomato market, and called as fruit tomato due to its sweetness and excelent flavor.
Right: Fruit of Earl’s Favourite-type melon, which is an unique melon genotype in Japan, and a breeding material for Japanese high quality melon cultivars.

Tomato and melon fruits were photographed by Kyoko Hiwasa-Tanase (University of Tsukuba) and Yoshiteru Sakata (National Agricultural and Food Research Organization), respectively.
A flower which likes wet environment
There are many caves in lime stone areas in rain tropics of Southeastern Asia. Such places are affluent in water supply, that is sometimes too much for some plants. Alocasia revera N.E.Br., shown here, is not such a weak weeds. It grows often in the entrance of caves where it is exposed to high-calcium, and alkali water supplied from the caves. A. reversa also enjoys rich nitrogen and phosphate, in the form of guano: excrements of bats that live in the caves. A. reversa is characteristic with its delicately variegated leaves with unequal distribution of intercellular spaces in the palisade tissue, and its lovely white bract with a tinge of pale purple on the edge. It's tough epidermis with thickened wax is evident in both organs, which enables this species to tolerate high humidity.

Photographed by Hirokazu Tsukaya (Univ. Tokyo) in 2 Sept, 2010 (Pentax Optio W80).
A classic flower known from the 18th century
The 18th century was a peaceful era in Japan, during which a unique horticultural culture has developed. Boku-han, a cultivar of Camellia japonica, is a mutant in which stamens are transformed into white petaloids. Because pistils are complete and fertile, this cultivar has been often used as a parental line for breeding. This cultivar was formerly described in a catalog of horticultural plants in Edo (ancient Tokyo) in 1719. Owing to the strong contrast between the deep crimson red petals and the white petaloids, and in addition to its slender, delicate branching nature, Boku-han has been appreciated by many flower lovers and has been widely spread in Japan. Now Boku-han is also named as “Gakko” or moonlight, in the western part of Japan. Photographed by Hirokazu Tsukaya (Univ. Tokyo) in Kamakura, Japan, in 11 March, 2012 (Pentax Optio W80).

Photographed by Hirokazu Tsukaya (Univ. Tokyo) in Kamakura, Japan, in 11 March, 2012 (Pentax Optio W80).
Adaptation to floods
In rain tropics, river bank is exceptionally good place for plants in terms of the availability of sun light. If you enter in rain forests, you will find that sun light is mostly absorbed by multilayered tree leaves from 40-m-high to a few-m-high. River bank is different. It is an open place and plants can enjoy sun shine there, although frequent floods suffer the area. If some mutations enable a particular strain of plants to have narrow leaves and strong roots, such strain is expected to tolerate the floods and can occupy the open area. It seems that occurrence of such mutation is not rare. Here is such a variant of an orchid, Arundina graminifolia. This species originally has narrow leaves (as the latin name “graminifolia” means: “having rice-family-like leaves”), but the variant adapted to the flood environment has much narrower leaves (less than half in width) that typically shows the evolutionary trend of plants to live along river bank. What genes are involved in this type of evolution? Trials to solve it are now on going in several laboratories.

Photographed by Hirokazu Tsukaya (The University of Tokyo) in Betung-Kerihun National Park, West Kalimantan, Borneo, in 26 December, 2011 (Pentax Optio W80).
Fruits of transgenic papaya
The papaya is the fruit of Carica papaya L., a member of the family Caricaceae, which is widely grown in tropical and subtropical regions of the world. e yellow orange, ripe fruits are edible and rich in vitamins, minerals, and ber, while green unripe fruits are known to rich sources of papain, an enzyme used as a component of meat tenderizers and so on. In this issue Retuta et al. (Page 339) carried out the evaluation of selected transgenic papaya lines which are resistant to papaya ringspot virus. e hermaphrodite fruits are pyriform in shape (front row), while the female fruits are rounded in shape (second row).
Dispersal by an ocean current
Anagallis arvensis L., with its characteristic deep blue petals, distributes very widely in subtropics and tropics. Its preference of seashore ambient might have helped this species to distribute so widely. Although seeds are too small to be dispersed by an ocean current, capsules being rather tough and light in weight, may enable the seeds inside to dri without severe damages. A. arvensis is also well-known to accumulate the blue pigment, anthocyanin, in the petal cells, in a unique manner. If you examine these tiny petals under a microscope, there you will observe unexpectedly beautiful images.

Photographed by Hirokazu Tsukaya (The University of Tokyo) in Yakushima Island, in 16 May, 2010 (Pentax Optio W80).
The oil plant for future biodiesel production
A tree of Jatropha curcas L., with bunches of developing fruits. Matured fruit contains 2-4 grains of seeds, which serve as a rich source of triacylglycerol for biodiesel production.

Photographed at campus of the University of e Ryukyus by Prof Yoshinobu Kawamitsu.
Flushing of Zelcova serrata
Zelcova serrata (Thunb.) Makino is distributed in Japan, as well as in China, Korea, and Taiwan. Nevertheless, this species is often seen as a tree typically representing forest vegetation of Kanto Plain of Japan, partly because this species has been preferentially planted along streets and in parks. This tree shows a characteristic and beautiful branching pattern; a wonderful colorations in Spring, Summer and Autumn, respectively; and supplies us with good quality wood. Bonsai, a Japanese art of horticulture, also loves to try to reproduce the elegant tree figure on a small pot. For this species the sprout season is also the season of full bloom, although not obvious due to the greenish coloration of flowers.

Photographed by Hirokazu Tsukaya (Univ. Tokyo) in Hongo campus, the University of Tokyo, Japan, in 13 April, 2011 (Pentax Optio W10).