UFMylation involves the covalent modification of substrate proteins with UFM1 (Ubiquitin-fold modifier 1) and is important for maintaining ER homeostasis. Stalled translation triggers the UFMylation of ER-bound ribosomes and activates C53-mediated autophagy to clear toxic polypeptides. C53 contains noncanonical shuffled ATG8-interacting motifs (sAIMs) that are essential for ATG8 interaction and autophagy initiation. However, the mechanistic basis of sAIM-mediated ATG8 interaction remains unknown. Here, we show that C53 and sAIMs are conserved across eukaryotes but secondarily lost in fungi and various algal lineages. Biochemical assays showed that the unicellular alga Chlamydomonas reinhardtii has a functional UFMylation pathway, refuting the assumption that UFMylation is linked to multicellularity. Comparative structural analyses revealed that both UFM1 and ATG8 bind sAIMs in C53, but in a distinct way. Conversion of sAIMs into canonical AIMs impaired binding of C53 to UFM1, while strengthening ATG8 binding. Increased ATG8 binding led to the autoactivation of the C53 pathway and sensitization of Arabidopsis thaliana to ER stress. Altogether, our findings reveal an ancestral role of sAIMs in UFMylation-dependent fine-tuning of C53-mediated autophagy activation.

Roots are highly plastic organs enabling plants to adapt to a changing below-ground environment. In addition to abiotic factors like nutrients or mechanical resistance, plant roots also respond to temperature variation. Below the heat stress threshold, Arabidopsis thaliana seedlings react to elevated temperature by promoting primary root growth, possibly to reach deeper soil regions with potentially better water saturation. While above-ground thermomorphogenesis is enabled by thermo-sensitive cell elongation, it was unknown how temperature modulates root growth. We here show that roots are able to sense and respond to elevated temperature independently of shoot-derived signals. This response is mediated by a yet unknown root thermosensor that employs auxin as a messenger to relay temperature signals to the cell cycle. Growth promotion is achieved primarily by increasing cell division rates in the root apical meristem, depending on de novo local auxin biosynthesis and temperature-sensitive organization of the polar auxin transport system. Hence, the primary cellular target of elevated ambient temperature differs fundamentally between root and shoot tissues, while the messenger auxin remains the same.

Ziziphus joazeiro Mart., popularly known as “juazeiro”, is a tree widely found in the northeast of Brazil. It is commonly used as an anti-inflammatory, antibacterial, antifungal, and analgesic agent. The stem extract exhibited, beside cytotoxic properties, substantial activity against the Gram-negative bacterium Allivibrio fischeri. UHPLC-ESI-Orbitrap-HR-MS analysis of the alkaloidal fraction of the crude methanolic stem extract of this species enabled the detection and putative identification of sixteen cyclopeptide alkaloids (CPAs), including four possibly new structures. According to the MS2 fragmentation analysis, from the sixteen identified CPAs, three possess a type-Ia1, one a type-Ia2, and twelve a type-Ib cyclopeptide alkaloid core. The structures of paliurine-C and -D were supported by NMR data.

The cullin‐RING E3 ligases (CRLs) regulate diverse cellular processes in all eukaryotes. CRL activity is controlled by several proteins or protein complexes, including NEDD8, CAND1, and the CSN. Recently, a mammalian protein called Glomulin (GLMN) was shown to inhibit CRLs by binding to the RING BOX (RBX1) subunit and preventing binding to the ubiquitin‐conjugating enzyme. Here, we show that Arabidopsis ABERRANT LATERAL ROOT FORMATION4 (ALF4) is an ortholog of GLMN. The alf4 mutant exhibits a phenotype that suggests defects in plant hormone response. We show that ALF4 binds to RBX1 and inhibits the activity of SCFTIR1, an E3 ligase responsible for degradation of the Aux/IAA transcriptional repressors. In vivo, the alf4 mutation destabilizes the CUL1 subunit of the SCF. Reduced CUL1 levels are associated with increased levels of the Aux/IAA proteins as well as the DELLA repressors, substrate of SCFSLY1. We propose that the alf4 phenotype is partly due to increased levels of the Aux/IAA and DELLA proteins.

Chirita drakei Burtt (now accepted as Primulina drakei (B.L.Burtt) Mich.Möller & A.Weber) is growing on limestone mountain slopes of Ha Long Bay islands in Vietnam. The chemical investigation of the aerial parts of C. drakei led to the isolation and structural elucidation of two new compounds named chiridrakoside A (1) and chiridrakoside B (2) besides twelve known compounds comprising five phenylethanoid glycosides (3–7), two lignans (8, 9), a phenyl propanoid (10), an anthraquinone (11), a furan derivative (12) and two triterpenes (13, 14). All described compounds, except 4, 5 and 11, were obtained for the first time from the genera Chirita or Primulina. The cytotoxic activity of the isolated compounds was evaluated against the four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Epoxyconiferyl alcohol (10) exhibited cytotoxic activity against the tested cell lines (IC50 from 46 to 128 μM).

Rothmannia talbotii, a hitherto chemically unexplored medicinal plant, is used in the Western Region of Cameroon to relieve fever. In our ongoing search for bioactive compounds from Cameroonian medicinal plants, a previously undescribed compound rothtalazepane (1), along with six known compounds, aitchisonide B (2), D-mannitol (3), β-D-glucopyranosyl-(6→1’)-β-D-glucopyranoside (4), monopalmitin (5), stigmasterol (6), and sitosterol 3-O-β-D-glucopyranoside (7) were isolated and characterized from the crude ethanol extract of the wood of R. talbotii. Rothtalazepane (1) exhibits no significant activity against several microbial strains, thus its function likely lies not in antimicrobial defense and it is not the active principle against urinary infections described for Rothmannia.

Four new 19-residue peptaibols, named tulasporins A–D (1–4), were isolated from the semi-solid cultures of Sepedonium tulasneanum. Their structures were elucidated on the basis of extensive ESI-HRMSn fragmentation studies as well as 1H NMR spectroscopic analyses. Interestingly, the structures of tulasporins A–D (1–4) resemble those of chrysospermins isolated earlier from cultures of S. chrysospermum. Previously, it was hypothesized that the peptaibol production by Sepedonium species correlates with the morphology of the aleurioconidia, as exclusively round-shaped aleurioconidia forming species produced peptaibols. Since the investigated Sepedonium tulasneanum produces oval aleurioconidia, this study can be considered as the first report of peptaibols from a Sepedonium strain with oval-shaped aleurioconidia. Thus, it could be demonstrated that both round as well as oval aleurioconidia forming Sepedonium species are able to produce peptaibols. Tulasporins A-D (1–4), when tested against phytopathogenic fungi, exhibited good growth inhibitory activity against both Botrytis cinerea and Phytophthora infestans, while they were devoid of significant activity against Septoria tritici.

Two new fungal pigments named schweinitzins A and B (1-2), together with (S)-torosachrysone-8-O-methyl ether (3) and emodin-6,8-di-O-methyl ether (4) have been isolated from the methanolic extract of the fruit bodies of Xylaria schweinitzii (Xylariaceae) collected in Cuc Phuong national park, Ninh Binh province, Vietnam, by silica gel column chromatography and preparative HPLC. Their structures were elucidated by spectroscopic analysis such as IR, UV-Vis, 2D NMR and FT-ICR-MS. In addition, two compounds (1 and 3) showed strong cytotoxicity against all four cancer cell lines, KB (a human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and HepG2 (hepatocellular carcinoma).

The essential oil from the leaves of Tagetes minuta L., growing wild in Yemen, was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. A total of 28 compounds were identified representing 74.2% of total oil composition. Major components of the essential oil were (Z)-ocimenone (15.9%), (E)-ocimenone (34.8%), (Z)-β-ocimene (8.3%), limonene (2.3%), (Z)-tagetone (1.8%), dihydrotagetone (1.4%) and an unidentified dimethylvinylketone derivative (20.6%). The oil showed moderate cytotoxic activity against MCF-7 breast tumor cells, with an IC50 of 54.7 ± 6.2 μg/mL. In the DPPH radical scavenging assay, T. minuta oil showed potent antiradical activity with an IC50 value of 36 μg/mL. Antimicrobial activity was also investigated on several microorganisms, and the essential oil exhibited high activity against methicillin-resistant Staphylococcus aureus (MRSA) with an inhibition zone of 23 mm. It also exhibited remarkable antifungal activity against Candida albicans with an inhibition zone of 26 mm.

The leaf essential oil of Tarchonanthuscamphoratus(Asteraceae) was obtained by hydrodistillation and analyzed by GC-MS. Fifty-six components were characterized, representing 94.2% of the total oil with oxygenated monoterpenes (48.3%) and oxygenated sesquiterpenes (32.7%) as the major groups. The principal constituents were identified as endo-fenchol (21.2%), trans-pinene hydrate (8.8%), caryophyllene oxide (7.5%), α-terpineol (6.4%), τ-cadinol (6.4%), and α-cadinol (5.2%). The essential oil was evaluated for its antimicrobial activity using a disc diffusion assay resulting in the moderate inhibition of a number of common human pathogenic bacteria, including methicillin-resistant Staphylococcus aureus(MRSA) and the yeast Candida albicans. The inhibition zones varied from 10 to 14mm/disc. Furthermore, the antioxidant capacity of the essential oil was examined using an in vitroradical scavenging activity test. The T. camphoratus essential oil scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), resulting in an IC50value of 5.6 mg/mL. At concentrations of 100 and 50μg/mL, the oil showed cytotoxic activity, with growth inhibition of 59.1% (±4.2), and 16.2% (±8.7) against HT29 tumor cells (human colonic adenocarcinoma cells), respectively(IC50 = 84.7 ± 7.5 μg/mL).