More Like this

1. Role of Phosphorus Type and Biodegradable Polymer on Phosphorus Fate and Efficacy in a Plant–Soil System

   https://doi.org/10.1021/acs.jafc.3c04735  

   Sigmon, Leslie R.; Vaidya, Shital R.; Thrasher, Corey; Mahad, Sumaya; Dimkpa, Christian O.; Elmer, Wade; White, Jason C.; Fairbrother, D. Howard (November 2023, Journal of Agricultural and Food Chemistry)

   Phosphorus (P) is critical for crop production but has a high nutrient use inefficiency. Tomato was grown in soil amended with five P-sources, used as-is, or embedded within a biodegradable polymer, polyhydroxyalkanoate (PHA). Correlation analysis identified treatments that maintain plant growth, improve bioavailable soil P, and reduce P loss. Three performance classes were identified: (i) micro- and nanohydroxyapatite, which did not increase bioavailable P, plant P-uptake, or change P in runoff/leaching compared to controls; (ii) monocalcium phosphate (MCP), dicalcium phosphate (DCP), calcium pyrophosphate nanoparticles (CAP), and PHA-MCP that increased P-uptake and/or bioavailable P but also increased P loss in runoff/leaching; and (iii) PHA-DCP and PHA-CAP, where increased bioavailable P and plant P-uptake were achieved with minimal P loss in runoff/leaching. In addition to identifying treatments that maintain plant growth, increase bioavailable P, and minimize nutrient loss, correlation plots also revealed that (i) bioavailable P was a good indicator of plant P-uptake; (ii) leached P could be predicted from water solubility; and (iii) P loss through runoff versus leaching showed similar trends. This study highlights that biopolymers can promote plant P-uptake and improve bioavailable soil P, with implications for mitigating the negative environmental impacts of P loss from agricultural systems. 

   more » « less
2. The Genus Paronychia (Caryophyllaceae) in South America: Nomenclatural Review and Taxonomic Notes with the Description of a New Species from North Peru

   https://doi.org/10.3390/plants12051064  

   Iamonico, Duilio; Montesinos_Tubée, Daniel B (March 2023, Plants)

   All the names in Paronychia described from South America are investigated. Five names (P. arbuscula, P. brasiliana subsp. brasiliana var. pubescens, P. coquimbensis, P. hieronymi, and P. mandoniana) are lecto- or neotypified on specimens preserved at GOET, K, LP, and P. The typification of nine names, first proposed by Chaudhri in 1968 as the “holotype” are corrected according to Art. 9.10 of ICN. Three second-step typifications (Art. 9.17 of ICN) are proposed for P. camphorosmoides, P. communis, and P. hartwegiana. The following nomenclatural changes are proposed: P. arequipensis comb. et stat. nov. (basionym: P. microphylla subsp. microphylla var. arequepensis), P. compacta nom. nov. pro P. andina (Philippi non Gray; Art. 53.1 of ICN), P. jujuyensis comb. et stat. nov. (basionym: P. hieronymi subsp. hieronymi var. jujuyensis), P. compacta subsp. boliviana comb. nov. (basionym: P. andina subsp. boliviana), and P. compacta subsp. purpurea comb. nov. (basionym: P. andina subsp. purpurea). A new species (P. glabra sp. nov.) is proposed based on our examination of live plants and herbarium specimens. P. johnstonii subsp. johnstonii var. scabrida is synonymized (syn. nov.) with P. johnstonii. Finally, P. argyrocoma subsp. argyrocoma is excluded from South America since it was based on misidentified specimens (deposited at MO) of P. andina subsp. andina. A total of 30 species (43 taxa including subspecies, varieties, subvarieties, and forms) are recognized, highlighting that for some (Paronychia chilensis, P. communis, P. setigera) we provisionally accept Chaudhri’s infraspecific classification, since the high phenotypic variability of these taxa is quite complicated and further investigations need to solve their taxonomy. 

   more » « less
3. Phosphorus chemistry in plant charcoal: interplay between biomass composition and thermal condition

   https://doi.org/10.1071/WF23096  

   Wu, Yudi; Pae, Lois M; Huang, Rixiang (January 2024, International Journal of Wildland Fire)

   Background Vegetation fire may change Phosphorus (P) cycling in terrestrial ecosystems through converting biomass into fire residues. Aim The aim of this study was to understand the chemistry and mobility of P in fire residues to help reveal P thermochemistry during biomass burning and post-fire P cycling. Methods A combination of sequential extraction, liquid 31P NMR and P K-edge XANES was used to obtain quantitative P speciation and explain P solubilisation behaviours of charcoal. Key results Despite varying diverse P species existing in raw biomass, only two P structural moieties – orthophosphate and pyrophosphate – were identified in charcoal. However, relative abundance of pyrophosphate differs greatly among charcoal samples from different biomass types, ranging between 0 and 40% of total extractable P. Although P K-edge XANES data indicates abundant soluble phosphate minerals, most P (70–90%) is likely occluded physically in the charcoal. The bicarbonate-extractable P (the Olsen-P) varies significantly and cannot be explained by surface P concentration or elemental stoichiometry alone. Conclusion and implications The results suggest the importance of starting biomass P speciation (i.e. molecular structure and complexation environment) and thermal conditions in controlling P speciation and availability in charcoal. The different P chemistry between charcoal and ash suggests the importance of fire types and severity in disturbing the P cycle. 

   more » « less
4. High species richness in the lichen genus Peltigera (Ascomycota, Lecanoromycetes): 34 species in the dolichorhizoid and scabrosoid clades of section Polydactylon, including 24 new to science

   https://doi.org/10.3767/persoonia.2023.51.01  

   Magain, N.; Miadlikowska, J.; Goffinet, B.; Goward, T.; Pardo-De la Hoz, C.J.; Jüriado, I.; Simon, A.; Mercado-Díaz, J.A.; Barlow, T.; Moncada, B.; et al (August 2023, Persoonia - Molecular Phylogeny and Evolution of Fungi)

   Applying molecular methods to fungi establishing lichenized associations with green algae or cyanobacteria has repeatedly revealed the existence of numerous phylogenetic taxa overlooked by classical taxonomic approaches. Here, we report taxonomical conclusions based on multiple species delimitation and validation analyses performed on an eight-locus dataset that includes world-wide representatives of the dolichorhizoid and scabrosoid clades in section Polydactylon of the genus Peltigera . Following the recommendations resulting from a consensus species delimitation approach and additional species validation analysis (BPP) performed in this study, we present a total of 25 species in the dolichorhizoid clade and nine in the scabrosoid clade, including respectively 18 and six species that are new to science and formally described. Additionally, one combination and three varieties (including two new to science) are proposed in the dolichorhizoid clade. The following 24 new species are described: P. appalachiensis , P. asiatica , P. borealis , P. borinquensis , P. chabanenkoae , P. clathrata , P. elixii , P. esslingeri , P. flabellae , P. gallowayi , P. hawaiiensis , P. holtanhartwigii , P. itatiaiae , P. hokkaidoensis , P. kukwae , P. massonii , P. mikado , P. nigriventris , P. orientalis , P. rangiferina , P. sipmanii , P. stanleyensis , P. vitikainenii and P. willdenowii ; the following new varieties are introduced: P. kukwae var. phyllidiata and P. truculenta var. austroscabrosa ; and the following new combination is introduced: P. hymenina var. dissecta . Each species from the dolichorhizoid and scabrosoid clades is morphologically and chemically described, illustrated, and characterised with ITS sequences. Identification keys are provided for the main biogeographic regions where species from the two clades occur. Morphological and chemical characters that are commonly used for species identification in the genus Peltigera cannot be applied to unambiguously recognise most molecularly circumscribed species, due to high variation of thalli formed by individuals within a fungal species, including the presence of distinct morphs in some cases, or low interspecific variation in others. The four commonly recognised morphospecies: P. dolichorhiza , P. neopolydactyla , P. pulverulenta and P. scabrosa in the dolichorhizoid and scabrosoid clades represent species complexes spread across multiple and often phylogenetically distantly related lineages. Geographic origin of specimens is often helpful for species recognition; however, ITS sequences are frequently required for a reliable identification. 

   more » « less
5. Wire like diplatinum, triplatinum, and tetraplatinum complexes featuring X[PtCCCCCCCC] _m PtX segments; iterative syntheses and functionalization for measurements of single molecule properties

   https://doi.org/10.1039/C9DT00870E  

   Zheng, Qinglin; Schneider, Jakob F.; Amini, Hashem; Hampel, Frank; Gladysz, John A. (April 2019, Dalton Transactions)

   Reaction of ( p -tol 3 P) 2 PtCl 2 and Me 3 Sn(CC) 2 SiMe 3 (1 : 1/THF/reflux) gives monosubstituted trans -Cl( p -tol 3 P) 2 Pt(CC) 2 SiMe 3 (63%), which with wet n -Bu 4 N + F − yields trans -Cl( p -tol 3 P) 2 Pt(CC) 2 H ( 2 , 96%). Hay oxidative homocoupling (O 2 /CuCl/TMEDA) gives all- trans -Cl( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 Cl ( 3 , 68%). Reaction of 3 and Me 3 Sn(CC) 2 SiMe 3 (1 : 1/rt) affords monosubstituted all- trans -Cl( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 (46%), which is converted by a similar desilylation/homocoupling sequence to all- trans -Cl[( p -tol 3 P) 2 Pt(CC) 4 ] 3 Pt(P p -tol 3 ) 2 Cl ( 7 ; 79%). Reaction of ( p -tol 3 P) 2 PtCl 2 and excess H(CC) 2 SiMe 3 (HNEt 2 /cat. CuI) gives trans -Me 3 Si(CC) 2 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 (78%), which with wet n -Bu 4 N + F − affords trans -H(CC) 2 Pt(P p -tol 3 ) 2 (CC) 2 H (96%). Hay oxidative cross coupling with 2 (1 : 4) gives all- trans -Cl[( p -tol 3 P) 2 Pt(CC) 4 ] 2 Pt(P p -tol 3 ) 2 Cl ( 10 , 36%) along with homocoupling product 3 (33%). Reaction of 3 and Me 3 Sn(CC) 2 SiMe 3 (1 : 2/rt) yields all- trans -Me 3 Si(CC) 2 ( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 ( 17 , 77%), which with wet n -Bu 4 N + F − gives all- trans -H(CC) 2 ( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 H (96%). Reaction of 3 and excess Me 3 P gives all- trans -Cl(Me 3 P) 2 Pt(CC) 4 Pt(PMe 3 ) 2 Cl ( 4 , 86%). A model reaction of trans -( p -tol)( p -tol 3 P) 2 PtCl and KSAc yields trans -( p -tol)( p -tol 3 P) 2 PtSAc ( 12 , 75%). Similar reactions of 3 , 7 , 10 , and 4 give all- trans -AcS[(R 3 P) 2 Pt(CC) 4 ] n Pt(PR 3 ) 2 SAc (76–91%). The crystal structures of 3 , 17 , and 12 are determined. The first exhibits a chlorine–chlorine distance of 17.42 Å; those in 10 and 7 are estimated as 30.3 Å and 43.1 Å. 

   more » « less