Inhibition of Cysteine Proteases via Thiol-Michael Addition Explains the Anti-SARS-CoV-2 and Bioactive Properties of Arteannuin B.

is the plant that produces artemisinin, an endoperoxide-containing sesquiterpenoid used for the treatment of malaria. extracts, which contain other bioactive compounds, have been used to treat other diseases, including cancer and COVID-19, the disease caused by the virus SARS-CoV-2. In this study, a methyl ester derivative of arteannuin B was isolated when leaves were extracted with a 1:1 mixture of methanol and dichloromethane.

A Century of Gibberellin Research.

Gibberellin research has its origins in Japan in the 19th century, when a disease of rice was shown to be due to a fungal infection. The symptoms of the disease including overgrowth of the seedling and sterility were later shown to be due to secretions of the fungus Gibberella fujikuroi (now reclassified as Fusarium fujikuroi), from which the name gibberellin was derived for the active component. The profound effect of gibberellins on plant growth and development, particularly growth recovery in dwarf mutants and induction of bolting and flowering in some rosette species, prompted speculation that these fungal metabolites were endogenous plant growth regulators and this was confirmed by chemical characterisation in the late 1950s.

Systematic identification of functional modules and cis-regulatory elements in Arabidopsis thaliana.

Background: Several large-scale gene co-expression networks have been constructed successfully for predicting gene functional modules and cis-regulatory elements in Arabidopsis (Arabidopsis thaliana). However, these networks are usually constructed and analyzed in an ad hoc manner. In this study, we propose a completely parameter-free and systematic method for constructing gene co-expression networks and predicting functional modules as well as cis-regulatory elements.

The major antennal chemosensory protein of red imported fire ant workers.

Some chemosensory proteins (CSPs) are expressed in insect sensory appendages and are thought to be involved in chemical signalling by ants. We identified 14 unique CSP sequences in expressed sequence tag (EST) libraries of the red imported fire ant, Solenopsis invicta. One member of this group (Si-CSP1) is highly expressed in worker antennae, suggesting an olfactory function.

Expression of gibberellin 20-oxidase1 (AtGA20ox1) in Arabidopsis seedlings with altered auxin status is regulated at multiple levels.

Bioactive gibberellins (GAs) affect many biological processes including germination, stem growth, transition to flowering, and fruit development. The location, timing, and level of bioactive GA are finely tuned to ensure that optimal growth and development occur. The balance between GA biosynthesis and deactivation is controlled by external factors such as light and by internal factors that include auxin.

The auxin transport inhibitor response 3 (tir3) allele of BIG and auxin transport inhibitors affect the gibberellin status of Arabidopsis.

The Arabidopsis gene BIG (formerly DOC1/TIR3/UMB1/ASA1) is known to encode a huge calossin-like protein that is required for polar auxin transport (PAT). Mutations at this locus, in addition to reducing PAT, can alter the sensitivity of plants to several hormones and light. The tir3-1 allele of BIG reduces the response of plants to application of the gibberellin (GA) precursors ent-kaurenoic acid and GA12 and its semidwarf phenotype is partially reversed by C19-GAs.

The Deoxyxylulose Phosphate Pathway for the Biosynthesis of Plastidic Isoprenoids: Early Days in Our Understanding of the Early Stages of Gibberellin Biosynthesis.

The identification of a novel pathway for isopentenyl diphosphate synthesis by Rohmer, Arigoni and colleagues in the early 1990's has led to a reappraisal of terpenoid biosynthesis in many organisms. It is now apparent that in plants there are two biosynthetic routes to isopentenyl diphosphate-the classical mevalonate pathway in the cytosol and the deoxyxylulose phosphate pathway in plastids. Sesquiterpenoids and sterols are predominantly synthesized in the cytosol by the mevalonate pathway whereas monoterpenoids, diterpenoids, the phytol side-chain of chlorophyll, carotenoids, and the nonaprenyl side-chain of plastoquinone-9 are synthesized within plastids by the deoxyxylulose phosphate pathway.

Characterization of new gibberellin-responsive semidwarf mutants of arabidopsis.

Chemical mutagenesis of Arabidopsis thaliana (L.) Heynh. yielded four semidwarf mutants, all of which appeared to be gibberellin (GA)-biosynthesis mutants.

The Gibberellin Status of lip1, a Mutant of Pea That Exhibits Light-Independent Photomorphogenesis.

Dark-grown seedlings of the lip1 (light independent photomorphogenesis) mutant of Pisum sativum L. display many features of de-etiolated growth and are similar in many respects to wild-type (WT) seedlings grown in the light. The involvement of gibberellins (GAs) with the mutant phenotype was examined by applying GA1 and GA20 to the mutant and WT, and by quantifying endogenous GA1, GA8, GA19, GA20, and GA29 levels in the two genotypes.

Expression of the le Mutation in Young Ovaries of Pisum sativum and Its Effect on Fruit Development.

The effect of the le mutation on the growth and gibberellin (GA) content of developing fruits was investigated using the near-isogenic lines of Pisum sativum L. 205+ (LeLe) and 205- (lele). Although stem elongation is known to be reduced in 205- plants by approximately 65%, the growth of pods and seeds was unaffected by the le mutation.

Use of an Acylcyclohexanedione Growth Retardant, LAB 198 999, to Determine Whether Gibberellin A(20) Has Biological Activity per se in Dark-Grown Dwarf (le) Seedlings of Pisum sativum.

Dwarf (le(5839)) seedlings of Pisum sativum respond to gibberellin A(20) (GA(20)) in the dark, although the same dosage of GA(20) applied to light-grown le(5839) seedlings elicits no growth response. The acylcyclohexanedione growth retardant, LAB 198 999, which is known to inhibit gibberellin oxidation and in particular 3beta-hydroxylation such as the conversion of GA(20) to GA(1), also inhibits the growth response of dark-grown dwarf (le(5839)) seedlings to GA(20). Thus, the biological activity of GA(20) in the dark appears to be a consequence of its conversion to GA(1), even though it is known from studies with light-grown seedlings that the le mutation reduces the conversion of GA(20) to GA(1).

Immunochromatographic purification of gibberellins from vegetative tissues of Cucumis sativus L: Separation and identification of 13-hydroxy and 13-deoxy gibberellins.

Immunological methods are described for the separation and purification of 13-hydroxy and 13-deoxy-gibberellins of Cucumis sativus. Qualitative and quantitative data show that 13-deoxygibberellins predominate over 13-hydroxygibberellins in stems and leaves of this species.

Gibberellins in developing fruits of Pisum sativum cv. Alaska: Studies on their role in pod growth and seed development.

Gibberellins A1, A8, A20 and A29 were identified by capillary gas chromatography-mass spectrometry in the pods and seeds from 5-d-old pollinated ovaries of pea (Pisum sativum cv. Alaska). These gibberellins were also identified in 4-d-old non-developing, parthenocarpic and pollinated ovaries.

Gibberellins in dark- and red-light-grown shoots of dwarf and tall cultivars of Pisum sativum: The quantification, metabolism and biological activity of gibberellins in Progress no. 9 and Alaska.

The stem growth in darkness or in continuous red light of two pea cultivars, Alaska (Le Le, tall) and Progress No. 9 (le le, dwarf), was measured for 13 d. The lengths of the first three internodes in dark-grown seedlings of the two cultivars were similar, substantiating previous literature reports that Progress No.

Gibberellins in immature seeds and dark-grown shoots of Pisum sativum : Gibberellins identified in the tall cultivar Alaska in comparison with those in the dwarf Progress No. 9.

Gibberellins (GAs) A17, A19, A20, A29, A44, 2βOH-GA44 (tentative) and GA29-catabolite were identified in 21-day-old seeds of Pisum sativum cv. Alaska (tall). These GAs are qualitatively similar to those in the dwarf cultivar Progress No.

Identification and localization of gibberellins in maturing seeds of the cucurbit Sechium edule, and a comparison between this cucurbit and the legume Phaseolus coccineus.

Twenty known gibberellins (GAs) have been identified by combined capillary gas chromatography-mass spectrometry in extracts from less than 10 g fresh weight of maturing seeds of the cucurbit Sechium edule Sw. The GAs are predominantly 3- and-or 13-hydroxylated. This is the first reported identification of non-conjugated 13-hydroxylated GAs in a cucurbit.

Metabolism of gibberellins by immature barley grain.

Gibberellins A1, A4, A9, A12-aldehyde, A20 and A51, each labelled with both a radioactive and stable isotope were fed to immature barley grain by injection into the endosperm. After 7 d, extensive metabolism of all substrates had occurred, and metabolites were identified by combined capillary gas chromatography-mass spectrometry. A proposed scheme of gibberellin metabolism in immature barley grain is presented.

The localization, metabolism and biological activity of gibberellins in maturing and germinating seeds of Pisum sativum cv. Progress No. 9.

Gibberellin A20 (GA20), GA29 and GA29-catabolite were quantified in cotyledons, embryonic axes, and testas of Pisum sativum cv. Progress No. 9 throughout the final stages of seed maturation and during germination.

Metabolism of [(13)C 1]gibberellin A 29 to [ (13)C 1]gibberellin-catabolite in maturing seeds of Pisum sativum cv. Progress No. 9.

The metabolism of GA29 during seed maturation in Pisum sativum cv. Progress No. 9 was further investigated.

The identification of gibberellins in immature seeds of Vicia faba, and some chemotaxonomic considerations.

GA17, GA19, GA20, GA29, GA44 and 13-hydroxy-GA12, now named GA53, were identified by GC-MS in immature seeds of Vicia faba (broad bean). Also identified were a GA catabolite, two polyhydroxykauranoic acids, and abscisic, phaseic and dihydrophaseic acids. The GAs of Vicia are hydroxylated at C-13, in common with those of other legumes.

Metabolism of gibberellin A29 in seeds of Pisum sativum cv. Progress No. 9; Use of [(2)H] and [ (3)H]GAs, and the identification of a new GA catabolite.

The metabolism of GA29 in maturing seeds of Pisum sativum cv. Progress No. 9 was further investigated, and the utility of (2)H-labelled GAs in conjuction with GC-MS is illustrated.

The biological activities of some new gibberellins (GAs) in six plant bioassays.

The biological activities of GA40, GA43, GA46, GA47, GA51 and GA4 20,4-lactone were tested over a wide range of concentrations in six plant bioassays. GA4 20,4-lactone showed the highest activity. Of the two 2α-hydroxylated compounds GA47 showed moderately high activity, and GA40 was slightly active.

Further studies on the metabolism of gibberellins (GAs) A9, A 20 and A 29 in immature seeds of Pisum sativum cv. progress No. 9.

Seed maturation of Pisum sativum cv. Progress No. 9 proceeds more slowly in winter than in summer even when the parent plants are grown in greenhouse conditions with light-and heat-supplementation.