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Baby-leaf vegetables are a trade name for leafy vegetables sold as leaves with petioles at the seedling stage. Amaranth (Amaranthus tricolor L.) is a nutritious baby-leaf vegetable containing many bioactive compounds. The effects of short-term ultraviolet B (UV-B) treatments on the growth and quality of baby leaf amaranth were studied, including the conditions of a 24-h recovery period after irradiation, and different irradiation intensities (3.0-9.0 W m

Oryza sativa cv. PTT1 (Pathumthani1) was treated with phenyl-urea-based synthetic cytokinin under drought stress. Soluble sugar contents were examined in rice flag leaves at tillering and grain-filling stages. The same leaf samples were used to analyze the differential abundance intensities of proteins related to metabolism and transport of soluble sugars, and the process of senescence. The results showed drought-induced accumulation of hexose sugars (glucose and fructose) in rice flag leaves, which could be corroborated with enhanced accumulation of MST8 under drought stress. On the other hand, cytokinin-treated plants maintained the normal contents of hexose sugar in their flag leaves under drought stress, alike well-watered plants. In the case of sucrose, cytokinin treatment reduced its accumulation at tillering stage, but the results were reversed at the grain-filling stage, where the cytokinin-treated plants maintained significantly higher contents of sucrose under drought stress. Growth stage dependent variations in sucrose contents corroborated with the accumulation of SPS (SPS1, SPS2, and SPS5) proteins, implicated in sucrose biosynthesis. In our study, among the proteins involved in sucrose transport, SUT1 transporter was induced by drought stress at both the growth stages, whereas SUT2 transporter accumulated equally in all the treatments. However, cytokinin treatment reversed the effect of drought on the accumulation of SUT1. Similarly, SWEET5, and SWEET13 proteins, which were induced by drought stress treatment, were inhibited by cytokinin treatment. However, the accumulation SWEET6, SWEET7, and SWEET15 was not influenced by the treatment of cytokinin in the flag leaves of rice. In addition, cytokinin treatment reduced the leaf wilting, enhanced the fresh weight and grain yield, and curtailed the accumulation of proteins involved in drought-induced senescence. In conclusion, the cytokinin treatment had a positive agro-economic impact on the rice plants and provided better drought adaptability.

Proline rich proteins (PRPs), earlier famous as animal salivary proteins, have now been proven as indispensable plant proteins. They are highly rich in proline amino acid residues at the N-terminus whereas a characteristic eight cysteine motif is located at the C-terminus. The PRPs support a number of developmental processes from germination to plant death. Under normal environmental conditions, PRP genes express customarily in different plant parts depending on the specific function to be carried out. During abiotic stresses, PRP genes exhibit an uneven pattern of transcriptional regulation depending on the time and intensity of stress. Transgenic plants overexpressing PRP genes show an enhanced tolerance to abiotic stresses. This review focuses on contemporary functions of PRPs during stresses and proposes that PRPs are involved in the regulation of free cellular proline content during stress in a well synchronized manner.

Artificial light has been used to control plant growth and secondary metabolite production. Artemisia annua L. plants were illuminated with three light-emitting diode (LED) spectra to investigate proteomic and biochemical responses. After 7 days, proteomic data revealed different protein numbers in leaves, stems, and roots under particular treatments. Results demonstrated increased accumulation of several proteins, including secondary metabolite-related proteins. The red light (R) (660 nm) highly induced terpenoid proteins. Similar biochemical profiles were observed in white light (W) (445, 544 nm) and blue light (B) (445 nm) conditions, while profiles from R treatment were different. Functional proteins of W and B treatments were involved in the MVA and MEP pathways and sesquiterpene biosynthesis. By contrast, unique proteins in R treatment were mainly expressed in sesquiterpene and tetraterpene biosynthesis. Specific relationships between biosynthetic proteins and sesquiterpenes were observed, suggesting the indispensable role of the light spectrum in regulating terpenoid biosynthesis.

Drought susceptible rice cultivar PTT1 (Pathumthani1) was treated with drought (&minus, 72 kPa) and CPPU (N-2-(chloro-4-pyridyl)-N-phenyl urea) @ 5 mg/L at tillering and grain-filling stages. Plants were tested for the effect of synthetic cytokinin on the parameters influencing the process of photosynthesis. Exogenous spray of CPPU improved the stomatal conductance of rice leaves, which was severely reduced by drought. The abundance intensities of proteins, associated with the stomatal conductance (ZEP, NCED4, PYL9, PYL10, ABI5, SnRK4, Phot1, and Phot2), were also in agreement with the positive impact of CPPU on the stomatal conductance under drought stress. Among the photosynthetic pigments, Chl b contents were significantly reduced by drought stress, whereas CPPU treated plants retained the normal contents of Chl b under drought stress. Subsequently, we examined the abundance intensities of chlorophyll synthase and HCR proteins, implicated in the biosynthesis of chlorophyll pigments and the conversion of Chl b to Chl a, respectively. The results indicated a drought-mediated suppression of chlorophyll synthase. However, CPPU treated plants retained normal levels of chlorophyll synthase under drought stress. In addition, drought stress induced HCR proteins, which might be the cause for reduced Chl b contents in drought stressed plants. Further, CPPU treatment helped the plants sustain photosynthesis at a normal rate under drought stress, which was comparable with well-watered plants. The results were further confirmed by examining the abundance intensities of two key proteins, RAF1 and Rubisco activase, implicated in the assembly and activation of Rubisco, respectively. CPPU treatment reversed the drought mediated suppression of these proteins at both of the growth stages of rice under drought stress. Based on the results, it can be suggested that synthetic cytokinins help the plants sustain photosynthesis at a normal rate under drought stress by positively influencing the determinants of photosynthesis at a molecular level.

“Plant factory with artificial lighting” (PFAL) refers to a plant production facility that can achieve mass production of vegetables year round in a controlled environment. However, the high-density planting pattern in PFALs causes low light conditions in the lower canopy, leading to leaf senescence in the outer leaves and thus to reductions in plant yields. In the present study, the effect of supplemental upward lighting underneath the plants on photosynthetic characteristics and plant yield was examined in lettuce, in comparison with supplemental downward lighting from above the plants at the same light intensity. Supplemental upward lighting increased the curvature factor of the photosynthetic response to light from above the plants. Moreover, supplemental upward lighting significantly enhanced the lettuce yield by retarding the senescence of the outer leaves. Here, we propose a novel cultivation system with a combination of downward lighting and supplemental upward lighting that can effectively increase plant growth and yield in PFALs.

Recalcitrant regeneration is one of the bottlenecks for plant improvement, especially in monocotyledonous species. In this research, plantlet regeneration of a native rice cultivar Oryza sativa ‘Barak Cenana’, high-value local Balinese red rice was successfully demonstrated. Compact nodular calli were induced from excised seed-derived mature embryos of ‘Barak Cenana’ rice. Although 2,4-D was necessary for callus induction, a combination of 2,4-D in regeneration medium caused reduction of green spot and shoot meristemoid differentiation. Root differentiation was firstly regenerated where meristematic shoots were thereafter developed from calli. The highest number of shoot regeneration regenerated from green spots and numbers of plantlet with complete shoot/root development were observed when transferred calli to Murashige and Skoog (MS) medium containing 5 mgL-1. Multiple shoot formation of regenerated plantlets revealed for efficient regeneration system, which was firstly reported in this present study and will potentially serve for plant improvement of this native rice, Barak Cenana.

Plants respond to abiotic stresses by activating a specific genetic program that supports survival by developing robust adaptive mechanisms. This leads to accelerated senescence and reduced growth, resulting in negative agro-economic impacts on crop productivity. Cytokinins (CKs) customarily regulate various biological processes in plants, including growth and development. In recent years, cytokinins have been implicated in adaptations to osmotic stresses with improved plant growth and yield. Endogenous CK content under osmotic stresses can be enhanced either by transforming plants with a bacterial isopentenyl transferase (IPT) gene under the control of a stress inducible promoter or by exogenous application of synthetic CKs. CKs counteract osmotic stress-induced premature senescence by redistributing soluble sugars and inhibiting the expression of senescence-associated genes. Elevated CK contents under osmotic stress antagonize abscisic acid (ABA) signaling and ABA mediated responses, delay leaf senescence, reduce reactive oxygen species (ROS) damage and lipid peroxidation, improve plant growth, and ameliorate osmotic stress adaptability in plants.

To understand the molecular responses of Thai jasmine rice (Oryza sativa L. ssp. indica cv. KDML105) under drought, proteomes of KDML105 cultivars and two check cultivars, namely NSG19 (tolerant) and IR20 (sensitive) were investigated. The effect of PEG6000 and mannitol for creating osmotic stress (−0.1 MPa to − 2.1 MPa) was tested in KDML105 before applied to the three cultivars. The leaf proteomes were analyzed by GeLC-MS/MS shotgun proteomics. Among 623 proteins identified, 53 proteins showed significant difference in protein expressions, which could be hierarchically classified into three clusters of proteins up-regulated in IR20, NSG19, or in KDML105. Coronatine-insensitive 1 protein that thought to be involved in stomatal closing was prominently observed in NSG19, regarding to its physiology of rapid stomatal closing and highest stability of photosystem II. WD-40 repeat protein which involves in cell death was induced in IR20. On the other hand, H-protein promoter binding factor-2a remarkably increa...

Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica) genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC) in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control) and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control) as water deficit sensitive, using Ward's method.

Artemisinin is a promising and potent antimalarial drug naturally produced by the plant Artemisia annua L. but in very low yield. Its artemisinin content is known to be greatly affected by both genotype and environmental factors. In this study, the production of artemisinin and leaf biomass in Artemisia annua L. was significantly increased by exogenous GA3 treatment. The effect of GA3 application on expression of proposed key enzymes involved in artemisinin yield was examined in both wild type (007) and FPS-overexpression (253-2) lines of A. annua. In the wild type (007) at 6 h post GA3 application there was an abrupt rise in FPS, ADS and CYP71AV1 expression and at 24 h a temporary and significant peak in artemisinin (1.45-fold higher than the control). After GA3 application in line 253-2, there was a dramatic rise in expression of FPS at 3 h, CYP71AV1 at 9 h and ADS at 72 h and accumulation of artemisinin after 7 days, which was a delay when compared with the wild type plant. Thus, increased artemisinin content from exogenous GA3 treatment was associated with increased expression of key enzymes in the artemisinin biosynthesis pathway. Interestingly, exogenous GA3 continuously enhanced artemisinin content from the vegetative stage to flower initiation in both plant lines and gave significantly higher leaf biomass than in control plants. Consequently, the artemisinin yield in GA3-treated plants was much higher than in control plants. Although the maximum artemisinin content was found at the full blooming stage [2.1% dry weight (DW) in 007 and 2.4% DW in 253-2], the highest artemisinin yield in GA3-treated plants was obtained during the flower initiation stage (2.4 mg/plant in 007 and 2.3 mg/plant in 235-2). This was 26.3 and 27.8% higher, respectively, than in non-treated plants 007 and 253-2. This study showed that exogenous GA3 treatment enhanced artemisinin production in pot experiments and should be suitable for field application.

Objective: To explore the effect of gibberellic acid (GA3) and its inhibitor paclobutrazol (PBZ) on chemical composition and their pharmacological effects on Andrographis paniculata (Burm. f.) Wall. ex Nees, and to clarify action mode of andrographolide. Methods: The chemical composition was extracted by sequential extraction with hexane, dichloromethane, ethyl acetate and methanol, respectively. Andrographolide and its derivatives were evaluated by HPLC. Moreover, the metabolic profiling was analyzed by GC-MS. Inhibitory effect of crude extracts was tested against Staphylococcus aureus using agar well diffusion method. Mode of action was tested against mutant yeast by spotting assay. Andrographolide were tested for their mode of action against eukaryotes. Results: Among different solvents, dichloromethane gave the highest yield of crude (3.58% DW), with the highest andrographolide content (8.3 mg/g DW). The effect of plant hormone (10 mg/L GA3 or PBZ) on phytochemical variations and bioactivity of Andrographis paniculata was demonstrated. It was found that PBZ promoted sesquiterpene compounds about 3.5 times over than GA3 treatment. But inhibitory effect of extracts against Staphylococcus aureus was highest in GA3 treated plants; andrographolide and 14-deoxy-11,12-didehydroandrographolide contents were significantly higher than those of water or PBZ. It was found that there were 11 strains involving in ergosterol biosynthesis, V-ATPase activity and homeostasis, and superoxide detoxification process. In this regard, andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis. Conclusions: It is found that GA3 promotes andrographolide and 14-deoxy-11,12-didehydroandrographolide content while PBZ promotes sesquiterpene content. Andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis. It might also affect mitochondria electron transport chain, leading to the occurrence of ROS, which can further harm cell organelles. However, the library screening is the first step to investigate mode of action of andrographolide.

Tetraploid plants of Artemisia annua L. exhibiting high-artemisinin-yield were successfully induced by treating excised leaves of in vitro plant with 0.1% colchicine. The chromosome number of original diploid plant was confirmed to be 2n=2x=18 whereas that of the tetraploid plant was 2n=4x=36. Morphological and anatomical characteristics of tetraploid plants were obviously different from the diploid counterpart. The tetraploid plants had larger sizes of root system, stomata and glandular secretory trichomes than diploid plant, whereas leaf size in tetraploid was smaller but thicker than diploid. The highest amount of artemisinin content was produced at flower blooming stage in both diploid (2.4% dry weight) and tetraploid (3.8% dry weight) lines. Based on the maximum yield of artemisinin, the optimum harvest time for the diploid lines was flower initiation stage but it was at full blooming stage for tetraploid lines. The highest artemisinin yield in tetraploid plants up to 3.0 mg plant−1 was detected at this stage which was 1.5 times greater than diploid plants. This is a first report that clearly showed the potential of chromosome doubling strategy to produce high-yield line of A. annua plant for artemisinin production.

Establishment of the efficient method for isolating the female germ unit (FGU; egg, synergid and central cell) is useful for the studies on the characterization of each FGU as well as in vitro fertilization and gametosomatic hybridization. In this study, an easy one-step enzymatic procedure was successfully developed to isolate FGU from ovules of Petunia hybrida without releasing the somatic protoplasts from ovular tissues, which could not be achieved in the previous studies. Each FGU was separately liberated after treating the ovules, which were collected from ovaries of flowers one day after anthesis, with an appropriate enzyme solution comprised of 10 g l−1 Cellulase Onozuka R-10, 10 g l−1 Macerozyme R-10, 0.6 M mannitol, 5 mM 2-morpholinoethane-sulfonic acid and 5 g l−1 potassium dextran sulfate, pH 5.8 with 50-rpm shaking for 2 h at room temperature. Isolated FGUs were distinguished by their specific size and characteristics. Fluorescent staining with 4′, 6-diamidino-2-phenylindole could identify the polar nuclei of central cell and the nuclear polarity of egg apparatus cells. After transfer into washing solution supplemented with 0.6 M mannitol using a micropump-connected microcapillary, about 80% of the isolated FGUs were viable for up to 8 h after the isolation, as determining by fluorescein diacetate staining.

In this study, the interference of T-DNA insertion upon Agrobacterium-mediated transformation on the biochemical expression of the host genome is discussed. Plant extracts of transgenic Artemisia annua L. with or without an overexpressed farnesyl pyrophosphate synthase gene have been investigated for their bioactivity and metabolic profile in comparison with wild type A. annua. The highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Candida albicans was observed in the T253 transgenic lines. Moreover, the crude extract from T253 showed higher antimalarial activity against the Plasmodium faciparum K1 strain than those of the others. The terpenoid constituents and antimicrobial properties of the plant samples were grouped by hierarchical clustering analysis. The clustering showed that squalene is a putative compound that might be involved in increasing the bioactivity of the transgenic line. In addition, T253 had a triterpene content that was about twice as great as that of the T253-2 line, which had a higher content of sesquiterpenes. However, both lines were transformed by the same FPS gene. These results suggested that the different bioactive properties observed in each transgenic line may be caused by variations in their terpenoid composition, which is affected by T-DNA insertion at different positions in the host plant.

Meristematic nodular calli (NOD) were successfully induced from various plant parts such as seeds, flower organs, shoot apices, stem segments and bulb scales of Lilium spp. on media containing 1mg/l picloram alone or in combination with 1mg/l cytokinin. In L. longiflorum, green friable callus (FC) was also induced from bulb scales. Suspension cultures established from both NOD and FC showed high proliferation rate. NOD retained high regeneration ability as well as stable ploidy level during the culture for more than 4 years, while the suspension culture of FC became tetraploid. Protoplasts were efficiently isolated from NOD in some species and cultivars after long term subculture in suspension cultures and the plants were successfully regenerated from the protoplasts of L. x formolongi.

Adventitious shoots and roots were directly formed from young flower bud explants of Agapanthus africanus on Murashige and Skoog (MS) medium containing 30g·L-1 sucrose, 2g·L-1 gellan gum, and kinetin or thidiazuron at 1mg·L-1 in combination with 1mg·L-1 NAA. Friable calli with a high rate of plant regeneration were also induced by culturing the explants on medium containing NAA, picloram or 2, 4-D at concentrations varying from 1 to 10mg·L-1, especially at low concentrations of picloram or 2, 4-D. Shoots were readily induced from these calli when transferred onto plant growth regulator-free or 1mg·L-1 zeatin-containing MS medium. Nodular compact calli were also formed with friable calli on medium supplemented with 2, 4-D or picloram. The compact calli induced with 1mg·L-1 picloram developed into somatic embryos. In both shoot and embryo regeneration systems, complete plantlets were obtained when they were transferred onto a medium containing no plant growth regulator.

Enhancement of artemisinin content in hairy root culture was investigated by using plant bioregulator in order to provide other alternative sources of artemisinin production besides the field grown plants. Synthetic cytokinin at different concentration: 1 mg L-1 (4 μM), 2.5 mg L-1 (10 μM) and 5 mg L-1 (20 μM) in the form of (2-chloro-4-pyridyl)-N-phenylurea (CPPU) was applied to culture media after 10 days of subculture. Artemisinin content was measured at different exposure periods (0, 24, 48, and 72 h). Our result shows that the highest artemisinin content was observed from hairy root that was treated with 5 mg L-1 (20 μM) of CPPU for 72 h which were about 3 folds higher than that of non-treated culture.Keywords: Artemisia annua L., hairy root, artemisinin, bioregulator

The aim of this investigation was to compare the transcriptional expression of starch metabolism, involving genes and physiological characters, in seedlings of two contrasting salt-tolerant rice genotypes, in response to salt-stress. The soluble sugar content in rice seedlings of both salt-tolerant and salt-sensitive genotypes was enriched, relating to starch degradation, in plants subjected to 200 mM NaCl. In the salt-tolerant cultivar Pokkali, a major source of carbon may be that derived from the photosynthetic system and starch degradation. In starch degradation, only Pho and PWD genes in Pokkali were upregulated in plants subjected to salt stress. In contrast, the photosynthetic abilities of IR29 salt-susceptible cultivar dropped significantly, relating to growth reduction. The major source of carbohydrate in salt-stressed seedlings of the IR29 cultivar may be gained from starch metabolism, regulated by ADP-glucose pyrophosphorylase (AGP), starch synthase (SS), starch branching enzyme (SBE), starch debranching enzyme (ISA), glucan-water dikinase (GWD), dispropotionating enzyme (DPE), phospho glucan-water dikinase (PWD) and starch phosphorylase (Pho). Also, the major route of soluble sugar in salt-stressed Pokkali seedlings was derived from photosynthesis and starch metabolism. This was identified as novel information in the present study.

Bioassay-guided fractionation of the MeOH extract from the stem bark of Neonauclea purpurea used in traditional medicine, resulted in the isolation of 2 indole alkaloids, cadambine (1) and alpha-dihydrocadambine (2), as well as a quinolic compound, 2,6-dimethoxy-1,4-benzoquinone (3). Antimalarial activity evaluation showed that compounds 2 and 3 exhibited mild in vitro antimalarial activity against Plasmodium falciparum, the chloroquine-resistant strain K1 with IC50 values of 6.6 and 11.3 microM, respectively. Compounds 1 and 2 showed no cytotoxicity to monkey (Vero) cells, but compound 3 showed weak cytotoxicity with an IC50 value of 1.19 microM.

Bioassay-guided fractionation of the MeOH extract from the stem bark of Neonauclea purpurea used in traditional medicine, resulted in the isolation of 2 indole alkaloids, cadambine (1) and α-dihydrocadambine (2), as well as a quinolic compound, 2,6-dimethoxy-1,4-benzoquinone (3). Antimalarial activity evaluation showed that compounds 2 and 3 exhibited mild in vitro antimalarial activity against Plasmodium falciparum, the chloroquine-resistant strain K1 with IC50 values of 6.6 and 11.3 μM, respectively. Compounds 1 and 2 showed no cytotoxicity to monkey (Vero) cells, but compound 3 showed weak cytotoxicity with an IC50 value of 1.19 μM.