General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foragin...General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foraging pressure.Clonal reproduction can enable unpalatable plant species to increase their population sizes while trending toward spatially aggregated distributions.However,the details of the relationship between clonal reproduction in unpalatable plants and their dynamics under intensive deer herbivory are not clear.We compared the population structures and spatial patterns of two coexisting unpalatable plant species,Arisaema ovale(with clonal reproduction)and A.peninsulae(without clonal reproduction)in a riparian forest intensively grazed by Sika deer,and examined the null hypothesis that the extent of spatial aggregation and local population size would not differ between the clonal and non-clonal Arisaema species.In a 0.36-ha plot,A.ovale had a larger population size(1087 individuals)with a higher abundance ratio of small plants(p<0.01)than A.peninsulae(84 individuals).Analyses of spatial point processes showed that both populations were spatially aggregated(p<0.05).The spatial aggregation of A.peninsulae,however,became weaker than that of A.ovale,when we excluded one dense patch originating from irregular seed dispersion.These results,excluding the aggregated distribution observed in A.peninsulae,suggested a substantial contribution of clonal reproduction to the expansion of the local A.ovale population following intensive grazing by Sika deer.展开更多
Morphologically putative introgressive hybrids of Arisaema sikokianum Franch. et Sav. and A. tosaense Makino were newly found in Kochi and Tokushima Prefectures in Japan. All the individuals have the same morphologica...Morphologically putative introgressive hybrids of Arisaema sikokianum Franch. et Sav. and A. tosaense Makino were newly found in Kochi and Tokushima Prefectures in Japan. All the individuals have the same morphological characteristics as A. tosaense excluding a purple spathe. Molecular analysis using PCR-RFLP of internal transcribed spacer (ITS) in nuclear DNA (nrDNA) indicates that these putative introgressive hybrids have the same pattern as A. tosaense. Moreover, the sequences of chloroplast DNA (cpDNA) of the putative introgressive hybrids were identical to A. sikokianum from Kochi Prefecture and A. tosaense from Tokushima Prefecture. The results suggest that the plants are introgressive hybrids of A. sikokianum and A. tosaense and that they have highly exchanged genes with A. tosaense.展开更多
A morphologically intermediate plant between Arisaema sikokianum Franch. et Sav. and A. serratum (Thunb.) Schott has been newly found in Kochi Prefecture, Shikoku, Japan. The putative hybrid has the intermediate morph...A morphologically intermediate plant between Arisaema sikokianum Franch. et Sav. and A. serratum (Thunb.) Schott has been newly found in Kochi Prefecture, Shikoku, Japan. The putative hybrid has the intermediate morphological characteristics of the parental species. Molecular analysis using PCR-RFLP of internal transcribed spacer (ITS) in nuclear DNA (nrDNA) indicates that the putative hybrid has a combined pattern of the two putative parent species. Moreover, the sequence result of chloroplast DNA (cpDNA) of the putative hybrid was identical to that of A. sikokianum. These results suggest that the putative hybrid is a hybrid between A. sikokianum and A. serratum and that it was formed by interactive gene exchanging via pollens from A. serratum to A. sikokianum. It is the first record of a hybrid between A. sikokianum and A. serratum.展开更多
Arisaema tosaense Makino develops either 1 or 2 leaves during both the male and female phases. To clarify the relationship between growth stage (sexual stage) and leaf number in this species, we conducted morphologica...Arisaema tosaense Makino develops either 1 or 2 leaves during both the male and female phases. To clarify the relationship between growth stage (sexual stage) and leaf number in this species, we conducted morphological analysis using A. tosaense, A. japonicum Bulme, A. sikokianum French. & Sav., and A. ringens (Thunb.) Schott. We found that increase in size of pseudostem of these Arisaema species is correlated to changes in the growth stage from sterile to male and from male to female phases. In particular, 1-leaf individuals of A. tosaense appeared at the beginning of both male and female phases, suggesting that they contribute to the earlier appearance of the fertile phase from sterile展开更多
Arisaema iyoanum Makino subsp. nakaianum (Ohba) H. Ohashi et J. Murata and A. ovale Nakai var. ovale are known to have one-leaved phenotype in both males and females;however, we discovered two-leaved individuals of th...Arisaema iyoanum Makino subsp. nakaianum (Ohba) H. Ohashi et J. Murata and A. ovale Nakai var. ovale are known to have one-leaved phenotype in both males and females;however, we discovered two-leaved individuals of these species. To elucidate the relationship between growth stage and leaf number of A. iyoanum subsp. nakaianum and A. ovale var. ovale, we conducted a morphological analysis of these plants. Our analysis suggested that the two-leaved individuals of A. iyoanum subsp. nakaianum and A. ovale var. ovale appeared only at the female phase. This suggested that one-leaved A. iyoanum subsp. nakaianum and A. ovale var. ovale individuals could not store the resources and hence changed to two-leaved individuals. This transformation could be explained by the fact that these species occur at high altitudes in mountain areas or regions covered in snow of the Japan Sea side, and their flowering time is also late compared with that in other sympatric Arisaema species.展开更多
Lectins are the carbohydrate-binding proteins of non-immune origin which have been the subject of intense investigation over the last few decades owing to the variety of interesting biological properties. Most of the ...Lectins are the carbohydrate-binding proteins of non-immune origin which have been the subject of intense investigation over the last few decades owing to the variety of interesting biological properties. Most of the lectins which have been purified and characterized from plants have been obtained from dicotyledons. In the present study a lectin was purified from tubers of a monocot plant Arisaema utile (AUL) Schott by affinity chromatography on asialofetuin-linked amino activated silica beads. AUL gave a single band in SDS-PAGE at pH 8.3 corresponding to subunit Mr 13.5 kDa. The native molecular mass of AUL was 54 kDa suggesting a homotetrameric structure. AUL gave multiple bands in isoelectric focusing and in native PAGE at pH 8.3. AUL was inhibited by N-acetyl-D-lactosamine (Lac NAc), a disaccharide and asialofetuin, a complex desialylated serum glycoprotein. When treated with denaturing agents, the lectin was stable in the presence of urea (3 M), thiourea (4 M) and guanidine HCl (4 M). AUL was a glycoprotein with a carbohydrate content of 1.2%. Complete loss of activity was observed upon modification of tryptophan residues of the lectin. The activity was reduced to 25% after modification of tyrosine. Chemical modification of arginine, histidine, serine and cysteine residues of AUL did not affect its activity. Using Far UV CD spectra the estimated secondary structure was 37% α-helix, 25% β-sheet and 38% random contributions. The lectin showed potent mitogenic response towards human lymphocytes. In vitro anti-proliferative assay using 11 human cancer cell lines resulted in 50% inhibition of six cell lines viz. SW-620, HCT-15, SK-N-SH, IMR-32, Colo-205 and HT-29 at 38, 42, 43, 49, 50 and 89 &#181;g/ml, respectively.展开更多
基金funded by a grant from The Yakumo Foundation for Environmental Science(2015,to Y.M.)
文摘General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foraging pressure.Clonal reproduction can enable unpalatable plant species to increase their population sizes while trending toward spatially aggregated distributions.However,the details of the relationship between clonal reproduction in unpalatable plants and their dynamics under intensive deer herbivory are not clear.We compared the population structures and spatial patterns of two coexisting unpalatable plant species,Arisaema ovale(with clonal reproduction)and A.peninsulae(without clonal reproduction)in a riparian forest intensively grazed by Sika deer,and examined the null hypothesis that the extent of spatial aggregation and local population size would not differ between the clonal and non-clonal Arisaema species.In a 0.36-ha plot,A.ovale had a larger population size(1087 individuals)with a higher abundance ratio of small plants(p<0.01)than A.peninsulae(84 individuals).Analyses of spatial point processes showed that both populations were spatially aggregated(p<0.05).The spatial aggregation of A.peninsulae,however,became weaker than that of A.ovale,when we excluded one dense patch originating from irregular seed dispersion.These results,excluding the aggregated distribution observed in A.peninsulae,suggested a substantial contribution of clonal reproduction to the expansion of the local A.ovale population following intensive grazing by Sika deer.
文摘Morphologically putative introgressive hybrids of Arisaema sikokianum Franch. et Sav. and A. tosaense Makino were newly found in Kochi and Tokushima Prefectures in Japan. All the individuals have the same morphological characteristics as A. tosaense excluding a purple spathe. Molecular analysis using PCR-RFLP of internal transcribed spacer (ITS) in nuclear DNA (nrDNA) indicates that these putative introgressive hybrids have the same pattern as A. tosaense. Moreover, the sequences of chloroplast DNA (cpDNA) of the putative introgressive hybrids were identical to A. sikokianum from Kochi Prefecture and A. tosaense from Tokushima Prefecture. The results suggest that the plants are introgressive hybrids of A. sikokianum and A. tosaense and that they have highly exchanged genes with A. tosaense.
文摘A morphologically intermediate plant between Arisaema sikokianum Franch. et Sav. and A. serratum (Thunb.) Schott has been newly found in Kochi Prefecture, Shikoku, Japan. The putative hybrid has the intermediate morphological characteristics of the parental species. Molecular analysis using PCR-RFLP of internal transcribed spacer (ITS) in nuclear DNA (nrDNA) indicates that the putative hybrid has a combined pattern of the two putative parent species. Moreover, the sequence result of chloroplast DNA (cpDNA) of the putative hybrid was identical to that of A. sikokianum. These results suggest that the putative hybrid is a hybrid between A. sikokianum and A. serratum and that it was formed by interactive gene exchanging via pollens from A. serratum to A. sikokianum. It is the first record of a hybrid between A. sikokianum and A. serratum.
文摘Arisaema tosaense Makino develops either 1 or 2 leaves during both the male and female phases. To clarify the relationship between growth stage (sexual stage) and leaf number in this species, we conducted morphological analysis using A. tosaense, A. japonicum Bulme, A. sikokianum French. & Sav., and A. ringens (Thunb.) Schott. We found that increase in size of pseudostem of these Arisaema species is correlated to changes in the growth stage from sterile to male and from male to female phases. In particular, 1-leaf individuals of A. tosaense appeared at the beginning of both male and female phases, suggesting that they contribute to the earlier appearance of the fertile phase from sterile
文摘Arisaema iyoanum Makino subsp. nakaianum (Ohba) H. Ohashi et J. Murata and A. ovale Nakai var. ovale are known to have one-leaved phenotype in both males and females;however, we discovered two-leaved individuals of these species. To elucidate the relationship between growth stage and leaf number of A. iyoanum subsp. nakaianum and A. ovale var. ovale, we conducted a morphological analysis of these plants. Our analysis suggested that the two-leaved individuals of A. iyoanum subsp. nakaianum and A. ovale var. ovale appeared only at the female phase. This suggested that one-leaved A. iyoanum subsp. nakaianum and A. ovale var. ovale individuals could not store the resources and hence changed to two-leaved individuals. This transformation could be explained by the fact that these species occur at high altitudes in mountain areas or regions covered in snow of the Japan Sea side, and their flowering time is also late compared with that in other sympatric Arisaema species.
文摘Lectins are the carbohydrate-binding proteins of non-immune origin which have been the subject of intense investigation over the last few decades owing to the variety of interesting biological properties. Most of the lectins which have been purified and characterized from plants have been obtained from dicotyledons. In the present study a lectin was purified from tubers of a monocot plant Arisaema utile (AUL) Schott by affinity chromatography on asialofetuin-linked amino activated silica beads. AUL gave a single band in SDS-PAGE at pH 8.3 corresponding to subunit Mr 13.5 kDa. The native molecular mass of AUL was 54 kDa suggesting a homotetrameric structure. AUL gave multiple bands in isoelectric focusing and in native PAGE at pH 8.3. AUL was inhibited by N-acetyl-D-lactosamine (Lac NAc), a disaccharide and asialofetuin, a complex desialylated serum glycoprotein. When treated with denaturing agents, the lectin was stable in the presence of urea (3 M), thiourea (4 M) and guanidine HCl (4 M). AUL was a glycoprotein with a carbohydrate content of 1.2%. Complete loss of activity was observed upon modification of tryptophan residues of the lectin. The activity was reduced to 25% after modification of tyrosine. Chemical modification of arginine, histidine, serine and cysteine residues of AUL did not affect its activity. Using Far UV CD spectra the estimated secondary structure was 37% α-helix, 25% β-sheet and 38% random contributions. The lectin showed potent mitogenic response towards human lymphocytes. In vitro anti-proliferative assay using 11 human cancer cell lines resulted in 50% inhibition of six cell lines viz. SW-620, HCT-15, SK-N-SH, IMR-32, Colo-205 and HT-29 at 38, 42, 43, 49, 50 and 89 &#181;g/ml, respectively.
