Botanical Studies

Ceriops australis (White) Ballment, Smith & Stoddart, a member of the mangrove family Rhizophoraceae, was originally recognized as C. tagal var. australis White but was raised to species rank based solely on isozyme features and the only distinctive morphological feature of the hypocotyl. Therefore, it was considered a sibling species of C. tagal (Perr.) C. B. Rob. The goal of this study was to test the previous assessment that C. australis and C. tagal differ consistently only in hypocotyl morphology, in order to reevaluate the taxonomic status and to establish its geographic range. Principal components analysis was employed to analyze 29 morphological characters of herbarium specimens from Australia, Madagascar, and Sumatra tentatively identified as C. australis and C. tagal, and two well differentiated distinct taxa were recognized. In addition, both of the detailed morphological features based on fresh and herbarium materials and the intron sequences of trnL gene from plastid DNA support this conclusion. This finding disagrees with previous assessment and supports the current taxonomic status of C. australis. Here, a key to these two species is provided, and a revised distribution range of C. australis is established. This is the initial report of C. australis' occurrence in a part of Indonesia, in addition to areas of Australia and Papua New Guinea.

A virus (isolate: Ca-M19) capable of inducing local lesions on Chenopodium quinoa Willd. was isolated from calla lilies (Zantedeschia spp.). Subculture of Ca-M19 was easily maintained in C. quinoa, but a back inoculation from single lesion of C. quinoa to calla lilies has so far not been successful. Typical potyvirus-like flexuous particles were consistently detected in Ca-M19 infected plants, and a 1.3-kb DNA fragment was amplified from these plants by reverse-transcription polymerase chain reaction (RT-PCR) using potyvirus degenerate primers. The PCR product was cloned and its sequence analyzed (AF469171). The amplicon was revealed to correspond to the 3' terminal region of a potyviral genome. After comparing this sequence with known potyvirus sequences in the GenBank, we considered the virus a new species of Potyvirus based on the uniqueness in its coat protein gene (CP) and the 3' non-coding region (NCR). Comparative studies showed that Soybean mosaic virus (SMV) and Watermelon mosaic virus 2 (WMV 2) were the two most similar potyviruses with Ca-M19, but they shared only 80% of nucleotide identities in CP and NCR with Ca-M19. Attempts to purify a sufficient quantity of Ca-M19 from C. quinoa for preparation of antibodies were unsuccessful. Alternatively, Ca-M19 CP was expressed by the vector pET28b and purified from E. coli culture, and polyclonal antibodies were prepared in rabbits. The antibody was applied in ELISA, Western blotting, SDS-immunodiffusion and immuno-specific electron microscopy for the detection of Ca-M19 in calla lilies. It did not react with at least five calla lily infecting potyviruses, including Dasheen mosaic virus, Bean yellow mosaic virus, Konjak mosaic virus, Turnip mosaic virus, and Zantedeschia mild mosaic virus. Indirect ELISA and SDS-immunodiffusion tests showed that Ca-M19 was serologically related, but distinct from Bean common mosaic virus (BCMV), Black cowpea mosaic virus (BlCMV), Melon vein banding mosaic virus (MVbMV), Passionfruit mottle virus (PaMV), Passionfruit crinkle virus (PCV), Passionfruit woodness virus (PWV), Soybean mosaic virus (SMV), Watermelon mosaic virus 2 (WMV 2), and Zucchini yellow mosaic virus (ZYMV). Besides serological techniques, a primer pair (M19u/M19d) and a DNA probe were designed which could also specifically detect and differentiate Ca-M19 from other viruses. By the use of specific antibodies in ELISA, Ca-M19 was frequently detected in calla lily plants collected from several major calla lily production townships in Taiwan. Among 86 field samples positively reacting to the antibody, 77 of them exhibited evident systemic mosaic symptoms, but these symptomatic plants were confirmed to be infected simultaneously by other viruses. Nine plants were found to be infected by Ca-M19 alone. These plants were confirmed to have remained symptomless throughout a 6-month observation period. Therefore, we propose naming this isolate Calla lily latent virus (CLLV) for its inability to develop any visible symptoms on calla lily.

In a study of small subunit ribosomal RNA (SSU-rRNA) gene sequences in cereal and a grass Phaeosphaeria species, group I introns were found in 9 of 10 P. avenaria f. sp. avenaria (Paa) isolates from oat (Avena sativa L.), 1 of 2 Phaeosphaeria sp. (P-rye) isolates (Sn48-1) from Polish rye (Secale cereale L.), 1 Phaeosphaeria sp. (P-dg) isolate (S-93-48) from dallis grass (Paspalum dilatatum Poir.) and both heterothallic P. a. f. sp. triticea (Pat2) isolates (ATCC26370 and ATCC26377) from foxtail barley (Hordeum jubatum L.). There were no group I introns in wheat- and barley-biotype P. nodorum (PN-w and PN-b), homothallic P. a. f. sp. triticea (Pat1) and P. a. f. sp. triticea (Pat3) from the state of Washington. Based on the reference 16S rDNA nucleotide sequence of Escherichia coli (accession number J01695), the intron-inserted positions of Pav.nS943, Pse.nS943, Ppa.nS1199 and Pho.nS1533 were determined to be at nt943, nt943, nt1199 and nt1533, respectively. The sizes of the introns were 362 bp for Pav.nS943 (from Paa), 363 bp for Pse.nS943 (from P-rye), 460 bp for Pho.nS1533 (from Pat2) and 383 bp for Ppa.nS1199 (P-dg). The intron-inserted position at nt1533 found in SSU-rRNA of Pat2 pathogen was newly discovered. The phylogenetic relationships based on aligned conserved secondary structure component sequences of group I introns showed that three introns from cereal Phaeosphaeria species (Pav.nS943, Pse.nS943 and Pho.nS1533) were likely affiliated with subgroup IC1 introns while Ppa.nS1199 intron from the dallis grass pathogen belonged to subgroup IE3.

In the literature, semicarbazide-sensitive amine oxidase (SSAO) in plasma was elevated in diabetes mellitus and heart failure. SSAO catalyzed the oxidative deamination of various amines to produce hydrogen peroxide, which is one possible source of oxidative stresses. In this research, galacturonic acid hydroxamate (GalA-NHOH), but not GalA, effectively inhibited SSAO activities from bovine plasma and porcine plasma in a dose-dependent manner, and the IC(50) values were 0.041 and 0.018 mM, respectively. The SSAO activities from bovine plasma and pig plasma were confirmed by the SSAO specific inhibitor of semicarbazide. Using AO activity staining in the 7.5% native-PAGE gels, it was also revealed that GalA-NHOH had inhibitory activities against SSAO from bovine plasma. GalA-NHOH showed mixed noncompetitive inhibition against bovine SSAO in respect to benzylamine (substrate) and benzylamine-SSAO (substrate-enzyme complex). It was found that the V'(max), and K'(m) values were reduced in the presence of GalA-NHOH (0.03 mM).

A cDNA for endo-β-1,4-glucanase (EGase) was isolated by RT-PCR, and rapid amplification of cDNA ends reaction from taro leaves (Colocasia esculenta var. esculenta). This single copy gene has 2,185 bps and an open reading frame (ORF) of 1,854 bps. A polypeptide of 618 residues was deduced from the ORF, with a calculated molecular mass of 68,434 Da and theoretical pI of 8.8. The remarked activities of the EGase on CMC plate revealed this enzyme to be involved in cellulose metabolism in taro. Taro EGase was identified as a kind of membrane-anchored EGase. Phylogenetic analysis showed it is a member of the γ subfamily and an ortholog of the Arabidopsis KORRIGAN gene (KOR), proposed to be involved in cytokinesis, pectin metabolism in the primary cell wall, and cell elongation. Transcripts of taro EGase are highly accumulated in 300 g tubers, in the upper part of 1,000 g tubers, and in rolled leaves undergoing rapid growth, indicating that taro EGase is involved in the regulation of plant growth. The expression pattern of soluble starch synthase III was similar to that of EGase during rapid growth of taro plant tubers. These results suggested that taro EGase, an ortholog of KOR in Arabidopsis, may play an important role in the rapid growth in taro.

Bacterial communities present in soils from the valley, middle-slope, and ridge sites of the Fushan forest in Taiwan were characterized using 16S rDNA analysis of genomic DNA after polymerase chain reaction amplification, cloning, and denaturing gradient gel electrophoresis analysis. Phylogenetic analysis revealed that the clones from nine clone libraries included members of the phyla Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, candidate division TM7, and Verrucomicrobia. Members of Proteobacteria, Acidobacteria, and Actinobacteria constituted 49.1%, 32.3%, and 6.3% of the clone libraries, respectively, while the remaining bacterial divisions each comprised less than 6%. The ridge site exhibited the most bacterial species number, indicating the influence of topography. Bacterial composition was more diverse in the organic layer than in the deeper horizons. In addition, bacterial species numbers varied across the gradient horizons.

Polymerase chain reaction (PCR)-based detection strategies were adopted to examine the etiology and vectorship of pear decline in Taiwan (PDTW). 16S rDNA sequences were amplified from total DNAs prepared from PDTW-affected pear trees Pyrus serotina Rehd. cv. Hengshan and pear psyllid Cacopsylla chinensis using PCR. According to the sequence analyses, C. chinensis carried phytoplasmas of two 16S rDNA groups, PDTW (group 16SrX) and PDTWII (a newly discovered group 16SrII phytoplasma associated with pear decline in Taiwan), that were associated with PDTW-infected pear trees. The 16S rDNA sequences of PDTW and PDTWII phytoplasmas that were amplified from diseased pear trees were identical to those from C. chinensis. Transmission trials of phytoplasmas associated with PDTW to healthy pear plants were successfully performed with C. chinensis. One of the 17 tested plants was infected with both PDTW and PDTWII phytoplasmas while ten were infected with PDTWII phytoplasma. In grafting tests, both PDTW and PDTWII phytoplasmas were effectively and separately transmitted from diseased pear to periwinkle plants (Catharanthus roseus). For detection purposes, specific primers were developed and adopted to detect both PDTW and PDTWII phytoplasmas by nested or semi-nested PCR. Transmission electron microscopic examinations revealed phytoplasma bodies in the sieve tubes and phloem parenchyma cells of diseased pears and in the intestinal wall cells of C. chinensis and C. qianli.

Microalgae are an important potential feedstock for biodiesel production. Understanding the physiology of lipid biosynthesis in microalgae is pivotal to their management in aquaculture. A freshwater green microalgal strain, UTEX 2219-4, was isolated from UTEX 2219, which was reported to contain two strains. Its ITS sequences were closely related to those in the family Scenedesmaceae. Nitrogen starvation, salt stress and osmotic stress greatly enhanced lipid biosynthesis in this strain, while a combination of nitrogen deficiency and osmotic stress produced the most dramatic effects. Chloroplasts condensed and photosynthesis efficiency declined about 50% after 3 days of nitrogen starvation. Chlorophyll degradation followed the same trend but was more severe than the reduction of photosynthesis efficiency. Oil body formation was not observed in the cells kept in the dark under nitrogen starvation, suggesting that photosynthesis, rather than autophagy, is the main player in oil body formation. Under non-saturating light intensity levels coupled with nitrogen starvation, the oil body formation under 200 μmol/m 2s light intensity was more efficient than that under 100 μmol/m 2s. DCMU blocked both photosynthesis and oil body formation, again suggesting that photosynthesis, rather than autophagy, provides the energy for oil body formation during nitrogen starvation.

Single nucleotide polymorphisms (SNPs) are known as the most detectable variations among related genomes. We estimated the SNPs between Tainung 67 (TNG67), an elite cultivar of rice (Oryza sativa) in Taiwan, and Nipponbare, the cultivar used for rice genome sequencing by the international consortium. More than 6,000 expressed sequence tag (EST) sequences from developing panicles of TNG67 were compared with the annotated gene sequences of Nipponbare. The estimated SNP rate is about 0.3% to 0.4% between the two cultivars, with most of the insertions or deletions (indels) occurring on the 5′ or 3′ untranslated regions (UTRs). The rate of transition substitutions on the 3′ UTR and the third codon positions is higher than that of transversions but lower on 5′ UTR and first codon positions. The synonymous (Ks) and non-synonymous (Ka) substitution distances are also calculated, and most of the Ka/Ks ratios are less than 1. Because the SNP density is higher than that of other traditional markers, detection of SNPs in this report with subsequent development of markers will allow genetic mapping and positional cloning between TNG67 and Nipponbare.

A thermophilic Streptomyces bangladeshensis isolate designated 77T-4 that can degrade poly(β-hydroxybutyrate) (PHB) was isolated from a soil sample in Taiwan. Isolate 77T-4 grew well in urea fructose oatmeal medium and produced a clear zone around the colony when grown on an agar plate containing emulsified PHB, indicating the presence of an extracellular PHB depolymerases. A PHB-degrading enzyme was purified to homogeneity from the culture supernatant. The molecular weight of the PHB-degrading enzyme was estimated to be approximately 40 kDa. A small portion of the N-terminal sequence (Ala-Val-Pro- Leu-Thr-Arg) of the purified enzyme was determined and found to share a significant homology with that of the PHB depolymerase of Streptomyces sp. MG.

In June 2008, Deahl et al. reported the first detection of two isolates of the A2 mating type of Phytophthora infestans on tomato from two locations in Taiwan based on the tests performed at USDA, Beltsville, using A1 and A2 mating types of P. infestans as testers. However, the third and fourth authors of the paper showed that these two isolates (Pi 214 and Pi 566) behaved as A1 mating type when paired with A1 and A2 testers of P. nicotianae (= P. parasitica) at Asian Vegetable Research and Development Center, Shanhua, Taiwan. This information was not included in the report. These two isolates along with two other isolates of P. infestans (Pi 215 and Pi 564) isolated from the same locations on the same dates were re-tested independently in three laboratories using A1 and A2 mating types of P. infestans, P. nicotianae and P. capsici as testers. All four isolates displayed oospore formation when paired with A2 but not A1 mating type regardless of species used as the testers, indicating that all of them are of the A1 mating type. New isolation of P. infestans from diseased tomato plants from the same locations also showed the presence of only the A1 mating type. These results refute the claim by Deahl et al. of the discovery of the A2 mating type of P. infestans from Taiwan.

Background The restoration of conventional tea plantations and the adoption of organic farming practices could impact soil organic carbon (SOC) and nitrogen (N) stocks. This study investigated the soil properties, SOC and N contents and stocks, and their vertical distributions of a secondary forest restored from an abandoned conventional tea plantation and a converted organic tea plantation. An adjacent conventional tea plantation employing similar intermediate farming served as a comparison. Results Within a 50-cm depth, the secondary forest exhibited a higher SOC stock of 115.53 ± 7.23 Mg C ha− 1 compared to 92.1 ± 8.54 Mg C ha− 1 for the conventional tea plantation. No significant differences in N stocks were seen between the two land uses. Significantly high SOC and N contents and stocks were found in the 0–10 cm layer of the secondary forest compared to the conventional tea plantation. No significant disparities in SOC and N stocks were found between the conventional and organic tea plantations within the 50 cm depth (92.1 ± 8.54 Mg C ha− 1 and 10.06 ± 1.01 Mg N ha− 1 vs. 97.47 ± 1.53 Mg C ha− 1 and 9.70 ± 0.10 Mg N ha− 1). However, higher levels of SOC and N contents and stocks were observed at a depth of 10 cm in the conventional tea plantation and below 10 cm in the organic tea plantation. Conclusions The C and N inputs derived from high litter production at the top soil strongly contributed to higher SOC and N contents and stocks in the secondary forest. The application of soybean amendments in the conventional tea plantation and the longer tea plantation age of the organic tea plantation influenced their distribution of SOC and N contents and stocks, respectively. Reverting a conventional tea plantation into a secondary forest contributed to C recovery and reaccumulation. The conventional tea plantation, employing similar intermediate farming practices, increased SOC and N contents and stocks in the surface soil compared to the organic tea plantation. However, adopting organic farming did not significantly increase SOC stocks compared to the conventional tea plantation. Supplementary Information The online version contains supplementary material available at 10.1186/s40529-023-00401-z.

Antioxidant activity assays were conducted using water (H) and methanolic (M) extracts of sixteen cultivars from indigenous wild bitter gourd (Momordica charantia L. var. abbreviata Seringe, MCA) in Taiwan. The scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals were different among MCA cultivars and the concentrations of 50% scavenging activity (IC50) for the effective cultivar was 181 μg/mL (H) and 246 μg/mL (M) in the former extract and 148 μg/mL (H) and 37 μg/mL (M) in the latter. For inhibitory activities against Cu2+-induced low-density-lipoprotein peroxidation, most MCA cultivars at 4000 μg/mL (especially for M extracts) showed protective activities and were equivalent to 0.8 mM Trolox by thiobarbituric acid reactive substance assays. These useful data may help promote the use and further research of MCA as an antioxidant in the health food industry.

Wild bitter gourd (Momordica charantia L. var. abbreviata Seringe, MCA), which is normally smaller than cultivated bitter gourd (Momordica charantia L., MC), both belong to the family Cucurbitaceae. The fresh fruits of MC and MCA are frequently used as vegetables in Taiwan. Water (H) and methanolic (M) extracts of sixteen cultivars from Taiwanese indigenous MCA (10 mg/mL) were tested for their antibacterial activities toward the methicillin-resistant Staphylococcus aureus subsp. aureus (ATCC 33591), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 10536), and Salmonella enterica subsp. enterica (ATCC 19126), and for their cytotoxic activities toward human fibrosarcoma HT 1080 cells. None of the extracts showed inhibitory activity against methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa, however, several H and M extracts (even H extracts that were heated at 100°C for 5 min) showed inhibitory activity against the growth of Escherichia coli and Salmonella enterica. For cytotoxic activities toward human fibrosarcoma HT 1080 cells, H extracts (1 mg/mL) from mature D, E, and F cultivars, and M extracts (1 mg/mL) from mature D and E cultivars showed similar cytotoxic activities compared to that of 10 μg/mL of doxorubicin. The use of MCA extracts as natural food additives to control food-borne pathogens and/or their development as health foods for chemoprevention in the future is discussed.

Cd toxicity was judged by the decrease in chlorophyll and protein contents. Twelve-day-old seedlings of rice cultivars [Tainung 67 (TNG67) and Taichung Native 1 (TN1)] were treated with or without CdCl2 at high temperature (35/30°C day/night). The results indicated that at high temperature, TNG 67 seedlings are a Cd-tolerant cultivar while TN1 seedlings are Cd-sensitive. On treatment with CdCl2, the abscisic acid (ABA) contents increased in the leaves of both TNG67 and TN1 seedlings grown at high temperature. Fluridone (Flu), an inhibitor of carotenoid biosynthesis, treatment, reduced ABA accumulation, increased transpiration rate and Cd content, and decreased Cd tolerance of TNG67 seedlings grown at high temperature. Flu's effect on Cd toxicity of TNG 67 seedlings was reversed by the application of ABA. For TN1 rice seedlings grown at high temperature, Flu treatment resulted in less Cd-induced ABA accumulation, as well as toxicity. These Flu effects were reversible by application of ABA. However, Flu treatment did not reduce Cd content in the leaves of TN1 seedlings grown at high temperature. Exogenous application of ABA at high temperature provoked chlorosis, a symptom of Cd toxicity, in the leaves of TN1, but not in TNG67 seedlings. Suggested roles for endogenous ABA in Cd tolerance of TNG67 seedlings and Cd toxicity of TN1 seedlings are discussed.

This study aimed to characterize the abundance and community structure of epilithic algae and to examine the effects of intensive agriculture in mountain streams of the Wuling area. There were significant seasonal variations in epilithic algal biomass, with higher values in spring and winter and lower values in summer and fall. Effects of agriculture on the subtropical streams of the Wuling area were significant and varied with the extent of agriculture in the catchment. The biomass was significantly higher in Yousheng Stream with a larger area of agriculture than in other streams. Diatoms were the most abundant species, contributing over 85% to the total cell number. Most of these were pennatae diatoms, of which the genus Achnanthidium was the most abundant in the area. However, the communities showed clear seasonal and spatial changes. BIOENV analysis suggested that the combination of water temperature, conductivity, NO 2+NO 3 and SiO 2 concentrations and current velocity comprised the major factors explaining seasonal changes in the community, while the combination of NO 2+NO 3 and SiO 2 concentration and grazer density comprised the major factors affecting spatial changes. Changes in abundance and community structure of epilithic algae can be used to monitor the effects of agriculture in tropical/subtropical mountain streams.

Temporal dynamics (2001-2003) of macroalgal abundance and assemblage structure in relation to environmental variables were studied on a reef in Du-Lang Bay in southeastern Taiwan. Sixty-six species were identified, with rhodophytes as the abundant species. Both the areal wet weight and areal dry weight biomass of total macroalgae increased as time advanced and reached the maximum in the winter of 2003 mainly due to the blooms of Gracilaria coronopifolia and Ceratodictyon/Haliclona, a red alga-sponge symbiose. Macroalgal cover varied temporally, % cover in 2001 and 2002 was low in spring but high in summer while that in 2003 was high in winter, spring, and summer and low in autumn. Species richness (species number), diversity (H') and evenness (J') increased, peaked in the winter in 2001, stabilized in 2002, and then decreased in 2003. The data of hierarchical cluster analysis and non-metric multidimensional scaling ordination of species similarities between different sampling times and the results of an analysis of similarity (ANOSIM) showed that the macroalgal assemblage is structured primarily by year and secondarily by season. Although H' and J' showed fewer changes, the k-dominance curve and a decrease in species number as time advanced suggest a switch of species structure from a highly diversified community to a less diversified one. The similarity percentage breakdown procedure (SIMPER) analysis shows that G. coronopifolia and Ceratodictyon/ Haliclona are the species contributing to year-over-year and seasonal differences in species structure. The comparison of macroalgal compositions with environmental variables indicates that decreasing soluble-reactive phosphorus (SRP) concentrations and increasing salinity are the best combination of environment variables to explain the yearly changes in algal compositions. Seasonal variations in species structure were associated with temporal variations in temperature, precipitation, salinity, and NH 4+. In conclusion, the nearshore macroalgal assemblage in Du-Lang Bay in Taitung in southeastern Taiwan during 2001-2003 became less diversified over time; the structure is modified yearly by increased nitrogen/phosphorus levels, and salinity and is also affected seasonally by fluctuating temperature and precipitation.

Molecular markers are capable of discriminating specific constituents of genome and monitoring genomic introgression of interspecific hybrids. In this study, we isolate and characterize a BB genome specific RAPD, Opun210, from Oryza punctata Kotschy ex Steud (W1593), an African native wild rice. We demonstrate the Opun210 as a highly species-specific marker. The Opun210 sequence is 789 base pairs in length and estimated at 5.3 × 104 copies in O. puntata (W1593) haploid genome, which contains the most repeats of Opun210 among Oryza species. The results of DNA sequence alignments among Opun210 and a few hits in the GenBank found that a relatively high similarity was in position -500 nucleotides regions at the 5′ ends, but a low similarity was in the rest of the nucleotides at the 3′ ends. SCAR-PCR profiles indicates that this fragment was specific to BB genome. Furthermore, the Opun210 sequence at position 430-480 nucleotides putatively encodes a peptide with 88% identity to a Ty3-gypsy retrotransposon protein or a peptide with 94% identity to a hypothetical protein. The results of Southern hybridization and fluorescent in situ hybridization (FISH) indicated that the repetitive Opun210 sequences dispersed throughout the entire genome of O. punctata. The origin and divergence of the Opun210 sequence in genus Oryza is discussed based on the investigations in this study.

Five structure-related myricetin galloylglycosides isolated from leaves of Acacia confusa were previously reported (Lee et al., 2000, J. Nat. Prod., 63, 710-712). However, the structure-activity relationships were not reported. In this research, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibitory activities against semicarbazide-sensitive amine oxidase (SSAO) and angiotensin rhamnopyranoside 7-methyl ether (compound 1, 630 Da), myricetin 3-O-(2"-O-galloyl)--rhamnopyranoside 7-methyl ether (compound 2, 630 Da), myricetin 3-O-(2"-O-galloyl)--rhamnopyranoside (compound 3, 616 Da), myricetin 3-O-(3"-O-galloyl)--rhamnopyranoside (compound 4, 616 Da), myricetin 3-O-(2", 3" -di-O-galloyl)--rhamnopyranoside (compound 5, 768 Da). For DPPH scavenging activity, the IC 50 compounds was 591, 1522, 3210, 1389, and 867 M, respectively. For SSAO inhibitory activity, the IC 50 for five compounds was 36.16, 93.20, 119.50, 88.20, and 39.35 M, respectively. The IC 50 of positive control that gallic acid in the R 3 position was the key role for both biological activities. For ACE inhibitory activity, compound 1, compound 2, and compound 5 showed dose-dependent inhibitory modes and the IC 50 was 60.32, Keywords: Acacia confusa; Angiotensin converting enzyme (ACE); 1, 1-diphenyl-2-picrylhydrazyl (DPPH); Myricetin galloylglycoside; Semicarbazide-sensitive amine oxidase (SSAO); Structure-activity relationships (SAR).

Pararuellia glomerata Y. M. Shui & W. H. Chen is described and illustrated as new species from Yunnan, China. It is similar to P. cavaleriei (H. Lév.) E. Hossain and Pararuellia delavayana (Baillon) E. Hossain, but differs by its cylindric spike and dense imbricate homomorphic bracts. Pollen grains, seeds and cross sections of the leaf epidermis are reported for this species of arid environments.

Fruit yield decreases gradually after several years of cultivation in Amomum villosum, an important Chinese medicinal herb, which is generally attributed to plant senescence. However, the reasons for plant senescence are still not clear until now. In this study, we investigated the effects of micronutrient deficiencies on leaf senescence. We hypothesized that micronutrient deficiencies may cause oxidative stress by disturbing cell metabolisms, which in turn leads to leaf senescence and decrease growth in A. villosum plants. Deficiencies of copper, zinc, and manganese decreased light-saturated photosynthetic rate and the contents of chlorophylls and soluble proteins but increased malondialdehyde content in A. villosum plants. The results indicated that oxidative stress and senescence occurred in leaves of A. villosum plants grown under micronutrient deficient conditions. Amomum plants were more susceptible to zinc deficiencies than to deficiencies of copper and manganese. The negative effects of micronutrient deficiencies on CO2 assimilation in chloroplast stroma were more serious than on electron transfer in thylakoids, increasing excess excitation energy. In most cases, micronutrient deficiencies decreased thermal dissipation of excess excitation energy and carotenoid content, leading to oxidative stress although antioxidant enzyme activities increased. Our results indicated that the micronutrient deficiencies caused oxidative stress, exacerbating leaf senescence and inhibiting biomass accumulation in Amomum plants.

Different ventilation closures, including aluminum foil (AF) and a varying number of dispense papers (DP) had different effects on leaf growth parameters, in vitro rooting, survival rate and the anatomical features of the leaf surface of in vitro and ex vitro acclimated plants of Scrophularia yoshimurae - an important medicinal plant. The lowest plant growth parameters and ex vitro acclimation rate (<7.0%) were obtained using AF as ventilation closure. A scanning electron microscopy (SEM) study of leaf surfaces of plants derived from different ventilation closure treatments showed that parameters - including density and size of epidermal cell and stomata, size of guard cells, and stomata aperture-differed significantly among various treatments, and this in turn affected plant survival rate. Leaves derived from AF treatment had higher epidermal cell (15094 cells/mm2) and stomata (38/mm2) densities than DP treatments. Well-ventilated container closures, such as with DP, improved the morphological characteristics of leaves and in turn enhanced the survival rate during ex vitro acclimation (maximum rate being 66.7%). The present study not only provides an improved micropropagation method of S. yoshimurae but also gives scientific reasons for the different acclimation rates obtained with various container closures.

We investigated the effects of heat shock (HS) on the subsequent cadmium (Cd)-induced ammonium ion (HN 4+) accumulation and the phenylalanine ammonia-lyase (PAL) activity in rice seedling leaves. Increases in PAL activity occurred prior to NH 4+ increases in rice leaves. Both of these Cd-induced increases were significantly deterred by the potent PAL inhibitor α-aminooxy-β-phenylpropionic acid. Exposing rice seedlings to 3 h HS in the dark effectively reduced subsequent Cd-induced increases in PAL activity and NH 4+ content. The HS effect can be mimicked by pretreating rice seedlings with exogenous H 2O 2, glutathione (GSH), ascorbic acid (AsA), or L-galactono-1,4-lactone (GalL, a precursor of AsA biosynthesis) under non-HS conditions. The protection that HS provides however, can be counteracted by imidazole, a NADPH oxidase inhibitor, buthionine sulfoximine (BSO, a GSH synthesis inhibitor), or lycorine (Lyc, an AsA synthesis inhibitor). Furthermore, the effects of BSO and Lyc can be reversed by the addition of GSH and AsA, respectively. The mechanisms of the protective effect of HS against subsequent Cd effects are discussed.