AtNSF regulates leaf serration by modulating intracellular trafficking of PIN1 in Arabidopsis thaliana

In eukaryotes,N-ethylmaleimide-sensitive factor(NSF)is a conserved AAA+ATPase and a key component of the membrane trafficking machinery that promotes the fusion of secretory vesicles with target membranes.Here,we demonstrate that the Arabidopsis thaliana genome contains a single copy of NSF,At NSF,which plays an essential role in the regulation of leaf serration.The At NSF knock-down mutant,atnsf-1,exhibited more serrations in the leaf margin.Moreover,polar localization of the PINFORMED1(PIN1)auxin efflux transporter was diffuse around the margins of atnsf-1 leaves and root growth was inhibited in the atnsf-1 mutant.More PIN1-GFP accumulated in the intracellular compartments of atnsf-1 plants,suggesting that At NSF is required for intracellular trafficking of PIN between the endosome and plasma membrane.Furthermore,the serration phenotype was suppressed in the atnsf-1 pin1-8 double mutant,suggesting that At NSF is required for PIN1-mediated polar auxin transport to regulate leaf serration.The CUPSHAPED COTYLEDON2(CUC2)transcription factor gene is up-regulated in atnsf-1 plants and the cuc2-3 single mutant exhibits smooth leaf margins,demonstrating that At NSF also functions in the CUC2 pathway.Our results reveal that At NSF regulates the PIN1-generated auxin maxima with a CUC2-mediated feedback loop to control leaf serration.

Fungal diversity notes 253-366:taxonomic and phylogenetic contributions to fungal taxa

Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa are detailed.In the Ascomycota the new genera Angustospora(Testudinaceae),Camporesia(Xylariaceae),Clematidis,Crassiparies(Pleosporales genera incertae sedis),Farasanispora,Longiostiolum(Pleosporales genera incertae sedis),Multilocularia(Parabambusicolaceae),Neophaeocryptopus(Dothideaceae),Parameliola(Pleosporales genera incertae sedis),and Towyspora(Lentitheciaceae)are introduced.Newly introduced species are Angustospora nilensis,Aniptodera aquibella,Annulohypoxylon albidiscum,Astrocystis thailandica,Camporesia sambuci,Clematidis italica,Colletotrichum menispermi,C.quinquefoliae,Comoclathris pimpinellae,Crassiparies quadrisporus,Cytospora salicicola,Diatrype thailandica,Dothiorella rhamni,Durotheca macrostroma,Farasanispora avicenniae,Halorosellinia rhizophorae,Humicola koreana,Hypoxylon lilloi,Kirschsteiniothelia tectonae,Lindgomyces okinawaensis,Longiostiolum tectonae,Lophiostoma pseudoarmatisporum,Moelleriella phukhiaoensis,M.pongdueatensis,Mucoharknessia anthoxanthi,Multilocularia bambusae,Multiseptospora thysanolaenae,Neophaeocryptopus cytisi,Ocellularia arachchigei,O.ratnapurensis,Ochronectria thailandica,Ophiocordyceps karstii,Parameliola acaciae,P.dimocarpi,Parastagonospora cumpignensis,Pseudodidymosphaeria phlei,Polyplosphaeria thailandica,Pseudolachnella brevifusiformis,Psiloglonium macrosporum,Rhabdodiscus albodenticulatus,Rosellinia chiangmaiensis,Saccothecium rubi,Seimatosporium pseudocornii,S.pseudorosae,Sigarispora ononidis and Towyspora aestuari.New combinations are provided for Eutiarosporella dactylidis(sexual morph described and illus trated)and Pseudocamarosporium pini.Descriptions,illustrations and/or reference specimens are designated for Aposphaeria corallinolutea,Cryptovalsa ampelina,Dothiorella vidmadera,Ophiocordyceps formosana,Petrakia echinata,Phragmoporthe conformis and Pseudocamarosporium pini.The new species of Basidiomycota are Agaricus coccyginus,A.luteofibrillosus,Amanita atrobrunnea,A.digitosa,A.gleocystidiosa,A.pyriformis,A.strobilipes,Bondarzewia tibetica,Cortinarius albosericeus,C.badioflavidus,C.dentigratus,C.duboisensis,C.fragrantissimus,C.roseobasilis,C.vinaceobrunneus,C.vinaceogrisescens,C.wahkiacus,Cyanoboletus hymenoglutinosus,Fomitiporia atlantica,F.subtilissima,Ganoderma wuzhishanensis,Inonotus shoreicola,Lactifluus armeniacus,L.ramipilosus,Leccinum indoaurantiacum,Musumecia alpina,M.sardoa,Russula amethystina subp.tengii and R.wangii are introduced.Descriptions,illustrations,notes and/or reference specimens are designated for Clarkeinda trachodes,Dentocorticium ussuricum,Galzinia longibasidia,Lentinus stuppeus and Leptocorticium tenellum.The other new genera,species new combinations are Anaeromyces robustus,Neocallimastix californiae and Piromyces finnis from Neocallimastigomycota,Phytophthora estuarina,P.rhizophorae,Salispina,S.intermedia,S.lobata and S.spinosa from Oomycota,and Absidia stercoraria,Gongronella orasabula,Mortierella calciphila,Mucor caatinguensis,M.koreanus,M.merdicola and Rhizopus koreanus in Zygomycota.

Regulation of cell reprogramming by auxin during somatic embryogenesis

How somatic cells develop into a whole plant is a central question in plant developmental biology.This powerful ability of plant cells is recognized as their totipotency.Somatic embryogenesis is an excellent example and a good research system for studying plant cell totipotency.However,very little is known about the molecular basis of cell reprogramming from somatic cells to totipotent cells in this process.During somatic embryogenesis from immature zygotic embryos in Arabidopsis,exogenous auxin treatment is required for embryonic callus formation,but removal of exogenous auxin inducing endogenous auxin biosynthesis is essential for somatic embryo(SE)induction.Ectopic expression of specific transcription factor genes,such as "LAFL" and BABY BOOM(BBM),can induce SEs without exogenous growth regulators.Somatic embryogenesis can also be triggered by stress,as well as by disruption of chromatin remodeling,including PRC2-mediated histone methylation,histone deacetylation,and PKL-related chromatin remodeling.It is evident that embryonic identity genes are required and endogenous auxin plays a central role for cell reprogramming during the induction of SEs.Thus,we focus on reviewing the regulation of cell reprogramming for somatic embryogenesis by auxin.

Plant cell totipotency: Insights into cellular reprogramming

Plant cells have a powerful capacity in their propagation to adapt to environmental change, given that a single plant cell can give rise to a whole plant via somatic embryogenesis without the need for fertilization. The reprogramming of somatic cells into totipotent cells is a critical step in somatic embryogenesis. This process can be induced by stimuli such as plant hormones, transcriptional regulators and stress. Here, we review current knowledge on how the identity of totipotent cells is determined and the stimuli required for reprogramming of somatic cells into totipotent cells. We highlight key molecular regulators and associated networks that control cell fate transition from somatic to totipotent cells. Finally,we pose several outstanding questions that should be addressed to enhance our understanding of the mechanisms underlying plant cell totipotency.