Annual Report 2006

More documents

Recommendations

Info

such as proteins. However, there have been no detailed studies about the defense activities of mulberry trees against insect herbivory or the involvement of mulberry latex in the plant defense. In this study, we addressed these subjects. We found that mulberry leaves are highly toxic to lepidopteran larvae other than the silkworm, (such as the Eri silkworm, and notorius pest species, the cabbage moth larvae, ), due to the ingredients of the latex. When Eri silkworm and the cabbage moth larvae were fed mulberry leaves, they bit in the leaves but they didnt grow, and died at last (Fig. 1, upper left photo, left part). The toxicity of mulberry leaves was lost when latex was washed off (Fig. 1, upper left photo, right part). Also, latex-added artificial diets showed toxicity and growth inhibitory effects to the Eri silkworm (Fig. 2A). Mulberry ( ) latex contained very high concentrations of alkaloidal sugar-mimic glycosidase inhibitors (sugar-mimic alkaloids) reported to have anti-diabetic activities, such as 1,4-dideoxy-1,4-imino-D-arabinitol (D-AB1), 1- deoxy nojirimycin (DNJ), and 1,4-dideoxy-1,4- imino-D-ribitol (Fig 1, right). Their concentrations, altogether, in latex reached 1.5-2.5% (8-18% to dry weight) in several mulberry varieties (Table 1), which were 100 times the concentrations previously reported from whole mulberry leaves. These sugar-mimicking alkaloids showed toxicities to caterpillars (Fig. 2 B,C), but not to the silkworm, (Fig. 2 D). Our results suggest that mulberry latex and sugarmimicking alkaloids in it play key roles in defense of mulberry against insect herbivory, and also suggest the existence of some adaptive mechanisms in the silkworm, . This study shows, for the first time in long history of sericulture, the existence of strong latex-borne defense mechanisms in mulberry, and gives practical answer to mulberrysilkworm interactions. This study, together with our previous studies on latex-borne defense mechanisms of papaya and fig trees carried out by cysteine proteases in latex, shows that medically applicable chemicals (i. e. anti-diabetic sugar-mimic alkaloids) exist in mulberry latex in surprisingly high concentrations (18% of dried latex), and they are easily purified from latex, and shows the possibility of mulberry latex as a source of interesting and applicable chemicals in medical and agricultural field. Also, this study will contribute to researches on pest resistance of mulberry varieties. Reference 1) Konno K., Ono H., Nakamura M., Tateishi K., Hirayama H., Tamura Y., Hattori M., Koyama A., Kohno K. (<strong>2006</strong>) Mulberry latex rich in antidiabetic sugar-mimic alkaloids forces dieting on caterpillars. 103, 1337-1341. Table 1 Concentrations of sugar-mimic alkaloids in mulberry latex Concentrations in latex (%) Species, populations, and cultivars D-AB1 DNJ 1,4-dideoxy-1,4-imino-D-ribitol (or ) Wild, Ishigaki, Okinawa, Japan Wild, Tsukuba, Honshu, Japan Cultivar Yukishirazu Cultivar Ichibei Cultivar Shinichinose Values indicate means SD ( = 4-5 for wild populations, = 2-3 for cultivars)
Fig. 2 Growth inhibitory effects of mulberry latex and sugar mimic alkaloids on the Eri silkworm, Mulberry latex (A) and two sugar-mimic alkaloids, D-AB1 (B) and DNJ (C), show remarkable growth inhibitory effects on the Eri silkworm, Thelarvaeofthesilkworm, are not at all affected by either of sugar-mimic alkaloids even at the high concentrations, suggesting that this species has developed some adaptive mechanisms to these compounds(D). Both sugar-mimic alkaloids and unidentified high molecular weight components contribute to the defense activities of mulberry latex (E). Percentages in graphs indicate mortalities of larvae (A-D).
Page 1 and 2: 2006
Page 3 and 4: Teruo Ishige, President The Nationa
Page 5 and 6: List of Publication Original paper
Page 7 and 8: Topics of Research in This Year Pos
Page 9 and 10: studies. To construct a fully satur
Page 11 and 12: Fig. 2 Geographical distribution of
Page 13 and 14: (ABR0015, ABR0257, ABR0417, ABR0495
Page 15: Mulberry latex defense mulberry tre
Page 19 and 20: Fig. 3 Change of the levels of luci
Page 21 and 22: Next, we examined the effect of tra
Page 23 and 24: G enome Research Department Introdu
Page 25 and 26: The Rice Annotation Project Databas
Page 27 and 28: industrial and agricultural concern
Page 29 and 30: One of the main problems involving
Page 31 and 32: Fig. 3 Mapping of QTL for rachis in
Page 33 and 34: two genes, XOO2263 and XOO4134 cont
Page 35 and 36: G enebank Genebank Project The NIAS
Page 37 and 38: using dormant winter buds. Also, we
Page 39 and 40: Insect and Animal Sciences Division
Page 41 and 42: Expression patterns of two novel ge
Page 43 and 44: Fig. 5 PGC and EBC fused cells PGCs
Page 45 and 46: cells. The epidermal cells maintain
Page 47 and 48: Animal and cell culture models for
Page 49 and 50: terminus, respectively. A signal se
Page 51 and 52: Fig. 2 Trehalose content of body pa
Page 53 and 54: Fig. 6 Birth weight of 11 adult SNT
Page 55 and 56: The role of glucose as a metabolic
Page 57 and 58: analysis using microsatellite marke
Page 59 and 60: Fig. 2 Recorded Electromyograms (le
Page 61 and 62: Table 1 Menu of Commercial silkworm
Page 63 and 64: Fig. 3 Expression of GFP gene in th
Page 65 and 66: also surveyed in the genetic stocks
Page 67 and 68:
esearch were located in or near gen
Page 69 and 70:
elatives results in severe reductio
Page 71 and 72:
and circadian clocks may control th
Page 73 and 74:
B iochemistry Department Structural
Page 75 and 76:
Proteomic analysis Based on the pro
Page 77 and 78:
photoautotrophic medium (Fig. 1B).
Page 79 and 80:
Fig. 4 Blast resistance of OsWRKY45
Page 81 and 82:
phosphatase activity by SIPK depend
Page 83 and 84:
the endosperm in co-operation with
Page 85 and 86:
isolated genes in transgenic Anal
Page 87 and 88:
Fig. 1 Gene structures and mutation
Page 89 and 90:
cytochimera among the mulberries (
Page 91 and 92:
15 G. Hariraj, Kinoshita Haruo, T.
Page 93 and 94:
49 Kameda Tsunenori, Teramoto Hidet
Page 95 and 96:
85 Matsuyama Shuichi, Ohkura Satosh
Page 97 and 98:
120 Ozawa Kenjiro, Kawahigashi Hiro
Page 99 and 100:
155 Taguchi-Shiobara Fumio, Yamamot
Page 101 and 102:
192 Ueno Osamu, Agarie Sakae, (2005
Page 103 and 104:
8 Murakami Ritsuko, Koyama Akio, Sh
Page 105 and 106:
20 Todoroki Junichi, Kaneko Hiroyuk
Page 107 and 108:
Executive Members and Research Staf
Page 109 and 110:
Developmental Biology Department Di
Page 111 and 112:
Research Leader Hayasaka Shoji Rese
Page 113 and 114:
Mutation Genetics Laboratory Head N
Page 115 and 116:
thousands of yen TOTAL BUDGET OPERA
Page 117:
Annual Report 2006 (Apr. 2005Mar. 2
show all

Annual Report 2006

Create successful ePaper yourself

Delete template?

Save as template?