ABSTRACT Pollen development and male gametogenesis are critically dependent upon cell polarization leading to a highly asymmetric division termed pollen mitosis I. A mutational approach was adopted in Arabidopsis thaliana identify genes involved these processes. Four independent gemini mutants were isolated which produce divided or twin-celled pollen. The pollen1 mutant characterized detail shown act gametophytically resulting reduced transmission through both sexes. showed an incompletely...

Abstract As a strategy for the identification of T-DNA-tagged gametophytic mutants, we have used T-DNA insertional mutagenesis based on screening distorted segregation ratios by antibiotic selection. Screening ~1000 transgenic Arabidopsis families led to isolation eight lines showing reproducible ~1:1, suggesting that these are putative mutants caused insertion at single locus. Genetic analysis transmission through reciprocal backcrosses with wild type showed severe reductions in genetic...

Summary Four mutants that show the delayed leaf senescence phenotype were isolated from Arabidopsis thaliana . Genetic analyses revealed they are all monogenic recessive mutations and fall into three complementation groups, identifying genetic loci controlling in Mutations these cause delay parameters examined, including chlorophyll content, photochemical efficiency of photosystem II, relative amount large subunit Rubisco, RNase peroxidase activity. Delay symptoms was observed during both...

Abstract Toc75 (translocon at the outer envelope membrane of chloroplasts, 75 kD) is protein translocation channel plastids and was first identified in pea (Pisum sativum) using biochemical approaches. The Arabidopsis (Arabidopsis thaliana) genome contains three Toc75-related sequences, termed atTOC75-I, atTOC75-III, atTOC75-IV, which we studied a range molecular, genetic, techniques. Expression atTOC75-III strongly regulated its highest level young, rapidly expanding tissues. By contrast,...

Ethylene-responsive factors (ERFs), within a subgroup of the AP2/ERF transcription factor family, are involved in diverse plant reactions to biotic or abiotic stresses. Here, we report that overexpression an ERF gene from Brassica rapa ssp. pekinensis (BrERF4) led improved tolerance salt and drought stresses Arabidopsis. It also significantly affected growth development transgenic plants. We detected salt-induced expressions transcriptional repressor gene, AtERF4, some Ser/Thr protein...

1-Aminocyclopropane-1-carboxylic acid (ACC) is a biosynthetic precursor of ethylene, gaseous plant hormone which controls myriad aspects development and stress adaptation in higher plants. Here, we identified mutant Arabidopsis thaliana , designated as ACC-resistant2 ( are2 ), displaying dose-dependent resistance to exogenously applied ACC. Physiological analyses revealed that mutation impaired various exogenous ACC-induced ethylene responses, while not affecting sensitivity other hormones...

Abstract The phospholipase A2 (PLA2) superfamily of lipolytic enzymes is involved in a number essential biological processes, such as inflammation, development, host defense, and signal transduction. Despite the proven involvement plant PLA2s many functions, including senescence, wounding, elicitor stress responses, pathogen relatively little known about PLA2s, their genes essentially remain uncharacterized. We characterized three four Arabidopsis thaliana PLA2 paralogs (PLA2-β, -γ, -Δ)...

We investigated the biological roles of Arabidopsis (Arabidopsis thaliana) GROWTH-REGULATING FACTOR (GRF) and GRF-INTERACTING (GIF) transcriptional complex in development gynoecia anthers. There are nine GRFs three GIFs Arabidopsis, seven posttranscriptionally silenced by microRNA396 (miR396). found that overexpression MIR396 gif1 gif2 double mutant background (gif1 35S:MIR396) resulted neither ovary nor pollen. Histological molecular marker-based analyses revealed gynoecial primordia failed...

Waterlogging (WL) is a key factor hindering soybean crop productivity worldwide. Plants utilize various hormones to avoid stress conditions, including WL stress; however, the physiological mechanisms are still not fully understood. To identify during stress, different phytohormones, such as ethephon (ETP; donor source of ethylene), abscisic acid, gibberellins, indole-3-acetic kinetin, jasmonic and salicylic acid were exogenously applied plants. Through this experiment, we confirmed...

Summary During male gametophyte development in A rabidopsis thaliana, the microspores undergo an asymmetric division to produce a vegetative cell and generative cell, which undergoes second give rise two sperm cells. SIDECAR POLLEN / LATERAL ORGAN BOUNDARIES DOMAIN ( LBD ) 27 plays key role of microspores. Here we provide molecular genetic evidence that combinatorial 10 with is crucial for rabidopsis. Expression analysis, transmission pollen viability assays, analysis demonstrated function...

The THO/TREX complex mediates transport of nascent mRNAs from the nucleus towards cytoplasm in animals, and has a role small interfering RNA-dependent processes plants. Here we describe five mutant alleles Arabidopsis thaliana THO2, which encodes core subunit plant complex. tho2 mutants present strong developmental defects resembling those plants compromised microRNA (miRNA) activity. In agreement, not only were levels siRNAs reduced mutants, but also mature miRNAs. As consequence, feedback...

Abstract The cellulose synthase-like proteins are a large family of in plants thought to be processive polysaccharide β-glycosyltransferases. We have characterized an Arabidopsis mutant with transposon insertion the gene encoding AtCSLA7 CSLA subfamily. Analysis transmission efficiency indicated that is important for pollen tube growth. Moreover, homozygous was embryo lethal. A detailed analysis seed developmental progression revealed embryos developed more slowly than wild-type siblings....

Summary Stable genetic transformation of Arabidopsis thaliana was achieved by simple in planta inoculation Agrobacterium tumefaciens strain LBA4404 harboring a binary vector pBl121. The procedure, which we call transformation, involves severing apical shoots at their bases, with the severed sites, and generation from sites. On average, 5.5% newly formed produced transformed progenies. These progenies (T2 generation) contained T-DNA genome as examined assaying encoded β-glucuronidase...

Cellular patterning and differentiation in plants depend on the balance of asymmetric symmetric divisions. Patterning male gametophyte (pollen grains) flowering requires division microspore followed by a germ cell to produce three highly differentiated cells: single vegetative two sperm cells. In Arabidopsis sidecar pollen (scp) mutants proportion microspores first divide symmetrically, then go 'four-celled' with an extra cell; however, details timing origin phenotypic defects scp identity...

As strawberries are susceptible to somaclonal variation when propagated by tissue culture techniques, it is challenging obtain the true-to-type plants necessary for continuous production of fruits stable quality. Therefore, we aimed develop an in vitro propagation method five different strawberry cultivars from meristems cultured media containing concentrations kinetin (Kn).For all cultivars, shoot induction was successful only medium without Kn and 0.5 mg L-1 Kn. The shoots obtained...

Successful delivery of sperm cells to the embryo sac in higher plants is mediated by pollen tube growth. The molecular mechanisms underlying germination and growth crop remain rather unclear, although these are crucial plant reproduction seed formation. By screening pollen-specific gene mutants rice (Oryza sativa), we identified a T-DNA insertional mutant Germinating modulator (GORI) that showed one-to-one segregation ratio for wild type (WT) heterozygous. GORI encodes seven-WD40-motif...

Summary The conserved Fused kinase plays vital but divergent roles in many organisms from Hedgehog signalling Drosophila to polarization and chemotaxis Dictyostelium. Previously we have shown that Arabidopsis termed TWO‐IN‐ONE (TIO) is essential for cytokinesis both sporophytic gametophytic cell types. Here using vivo imaging of GFP‐tagged microtubules dividing microspores show TIO required expansion the phragmoplast. We identify phragmoplast‐associated kinesins, PAKRP1/Kinesin‐12A...

Rupesh Tayade, TienDung Nguyen, Sung Aeong Oh, Yong Sik Hwang, In Sun Yoon, Deshmuk, Ki-Hong Jung, and Soon Ki Park. Plant Breeding Biotechnology 2018;6:1-18. https://doi.org/10.9787/PBB.2018.6.1.1

The highly specialized haploid male gametophyte-pollen consist of two sperm cells and a large vegetative cell. Successful fertilization requires proper growth timing rupture the pollen tube until it delivers cells, which occur immediately after grain hydrates. Although tight regulation on polar cell-wall expansion is fundamentally important, underlying molecular mechanism remains largely unknown, especially in crop plants. Here, we characterized function male-gene transfer defective 2...

Pollen tube growth is essential for successful double fertilization, which critical grain yield in crop plants. Rapid alkalinization factors (RALFs) function as ligands signal transduction during fertilization. However, functional studies on RALF monocot plants are lacking. Herein, we functionally characterized two pollen-specific RALFs rice (Oryza sativa) using multiple clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9-induced loss-of-function mutants,...