Multigene Analyses of Monocot Relationships

We present an analysis of supra-familial relationships of monocots based on a combined matrix of nuclear I8S and partial 26S rDNA, plastid atpB, matK, ndhF, and rbcL, and mitochondrial atp1 DNA sequences. Results are highly congruent with previous analyses and provide higher bootstrap support for nearly all relationships than in previously published analyses. Important changes to the results of previous work are a well-supported position of Petrosaviaceae as sister to all monocots above Acorales and Alismatales and much higher support for the commelinid clade. For the first time, the spine of the monocot tree has some bootstrap support, although support for paraphyly of liliids is still only low to moderate (79-82%). Dioscoreales and Pandanales are sister taxa (moderately supported, 87- 92%), and Asparagales are weakly supported (79%) as sister to the commelinids. Analysis of just the four plastid genes reveals that addition of data from the other two genomes contributes to generally better support for most clades, particularly along the spine. A new collection reveals that previous material of Petermannia was misidentified, and now Petermanniaceae should no longer be considered a synonym of Colchicaceae. Arachnitis (Corsiaceae) falls into Liliales, but its exact position is not well supported. Sciaphila (Triuridaceae) falls with Pandanales. Trithuria (Hydatellaceae) falls in Poales near Eriocaulaceae, Mayacaceae, and Xyridaceae, but until a complete set of genes are produced for this taxon, its placement will remain problematic. Within the commelinid clade, Dasypogonaceae are sister to Poales and Arecales sister to the rest of the commelinids, but these relationships are only weakly supported

Haploinsufficiency of interferon regulatory factor 4 strongly protects against autoimmune diabetes in NOD mice

Aims/hypothesis: Interferon regulatory factor (IRF)4 plays a critical role in lymphoid development and the regulation of immune responses. Genetic deletion of IRF4 has been shown to suppress autoimmune disease in several mouse models, but its role in autoimmune diabetes in NOD mice remains unknown. Methods: To address the role of IRF4 in the pathogenesis of autoimmune diabetes in NOD mice, we generated IRF4-knockout NOD mice and investigated the impact of the genetic deletion of IRF4 on diabetes, insulitis and insulin autoantibody; the effector function of T cells in vivo and in vitro; and the proportion of dendritic cell subsets. Results: Heterozygous IRF4-deficient NOD mice maintained the number and phenotype of T cells at levels similar to NOD mice. However, diabetes and autoantibody production were completely suppressed in both heterozygous and homozygous IRF4-deficient NOD mice. The level of insulitis was strongly suppressed in both heterozygous and homozygous IRF4-deficient mice, with minimal insulitis observed in heterozygous mice. An adoptive transfer study revealed that IRF4 deficiency conferred disease resistance in a gene-dose-dependent manner in recipient NOD/severe combined immunodeficiency mice. Furthermore, the proportion of migratory dendritic cells in lymph nodes was reduced in heterozygous and homozygous IRF4-deficient NOD mice in an IRF4 dose-dependent manner. These results suggest that the levels of IRF4 in T cells and dendritic cells are important for the pathogenesis of diabetes in NOD mice. Conclusions/interpretation: Haploinsufficiency of IRF4 halted disease development in NOD mice. Our findings suggest that an IRF4-targeted strategy might be useful for modulating autoimmunity in type 1 diabetes

Smilax bolavenensis Tagane & Soulad. 2023, sp. nov.

Smilax bolavenensis Tagane & Soulad., sp. nov. (Figs 1, 2) TYPE: — LAOS. Champasak Province: Paksong District, near Nong Luang Village, Dong Hua Sao National Park (Bolaven Plateau), 15°04′44.53″N, 106°12′27.36″E, 1249 m a.s.l., 17 Dec 2019, Souladeth et al . L3342 (holotype: FOF 0006673; isotypes BKF, KAG 155707). Smilax bolavenensis is similar to S. elegantissima Gagnepain (1934b: 619) from Vietnam in having an elongate inflorescence with slightly zigzag rachis longer than 20 cm, but clearly distinguished from it by its terete stem and petiole (vs. 4-angled with each corner narrowly winged) and 42–54-flowered umbels (vs. 7–12). Climbers to 4 m tall, all parts glabrous. Stems and branches subterete, without prickles and wings. Petioles 3.5–4.5 cm long, subterete; sheaths 1.2–1.7 × 0.7–1 cm. Tendrils up to 10.0 cm long, 1.0– 1.5 cm above from the base of sheath. Lamina ovate-oblong to narrowly ovate, (11.0–)15.2–22.4 × (3.5–) 5.8–13.6 cm, shiny brownish red to brownish yellowish on both surfaces when dry or paler and glaucous abaxially, apex acuminate, acumen up to 0.6 cm long, base cordate, 5-veined, major veins diverging at base of lamina, prominent abaxially, (0.9–) 1.7–2.5 cm interval (at widest point of lamina), connected with reticulate veinlets. Staminate inflorescence composed of spicately disposed umbels, to 33 cm long, 2–4-branched, rachis slightly zigzagged, not winged; umbels sessile, 22 per inflorescence, 42–54- flowered, prophylls ovate-lanceolate, 3.0–4.5 × 1.0– 1.2 mm, apex acuminate; receptacle of an umbel globose, 2.8 mm in diam.; bracteoles 4–5, ovate-triangular to oblong-obovate, 1.6–2.5 × 0.6–1.2 mm, apex acute. Staminate flower (before anthesis), tepals 6, free from base, outer ones ovate-oblong, 2.5–2.9 × 1.3–1.5 mm, inner ones narrowly ovate, 2.0–2.2 × 0.9–1.0 mm long, apex acute, stamens 6, filaments sessile, anthers oblong, 1.3 mm long; pedicels 0.3–0.7 mm long. Pistillate inflorescence, fruits and seeds not seen. Distribution:— Thus far known only from the Bolaven Plateau. Habitat:— Montane forests, 1240–1250 m a.s.l., dominated by Fagaceae, Lauraceae and Myrtaceae, along with some subcanopy trees such as Taberaemontana bovina (Apocynaceae), Aporosa yunnanensis (Phyllanthaceae), and Camellia bolavenensis (Theaceae). Phenology:— Staminate inflorescence with flower buds collected in December. Etymology:— Referring to the type locality, Bolaven Plateau. Vernacular name:— Kheau kheaung Bolaven (; Lao), suggested here. Kheau kheaung in Lao refers to a common name for Smilax. Preliminary conservation assessment:— Critically endangered (CR). During our five intensive field surveys in Bolaven Plateau 2018–2020, we found only one population with a few individuals in lower montane forest on the top of a plateau where we collected the above two specimens. Therefore, the most appropriate initial assessment of the IUCN conservation status for this species is critically endangered (CR) under criteria D (IUCN 2012). In the Bolaven Plateau, the forests at higher elevation have been decreasing due to dam construction and coffee plantations, which may produce negative effects for S. bolavenensis. Further information on its distribution and number of individuals/ populations is needed to accurately assess its status and conserve this species. Note: —Among the Smilax species in Laos, S. bolavenensis resembles S. glabra in leaf texture and venation patterns, and both species occur in Bolaven Plateau (specimens of S. glabra: Souladeth et al. L3754, FOF, KAG). However, S. bolavenensis is easily distinguishable from S. glabra by its long-spicately disposed sessile umbels (vs. only 1 umbel axillary in S. glabra) and its cordate leaf base (vs. cuneate to rounded). Additional specimen examined:— LAOS. Champasak Province: Paksong District, near Nong Luang Village, Dong Hua Sao National Park (Bolaven Plateau), 15°04′19.26″N, 106°12′38.67″E, 1248 m a.s.l., 10 Dec 2018, Tagane et al. L1964 (FOF 005293, FU, KAG 128065).Published as part of Tagane, Shuichiro, Souladeth, Phetlasy & Tamura, Minoru N., 2023, Smilax bolavenensis, a new species of Smilacaceae from southern Laos, pp. 55-60 in Phytotaxa 585 (1) on pages 56-58, DOI: 10.11646/phytotaxa.585.1.6, http://zenodo.org/record/767297

A New Combination in Heteropolygonatum (Convallariaceae, Polygonateae)

Volume: 10Start Page: 156End Page: 15