The yeast and human SKP1 genes regulate the mitotic cell cycle but are not yet known to be required for meiosis. Nine Arabidopsis homologues have been uncovered named ASK1 through ASK9 . Here, we report isolation characterization of a male sterile mutant show that defect was caused by Ds transposon insertion into gene. In ask1-1 mutant, abnormal microspores exhibit range sizes. Furthermore, during meiosis, although homologous chromosome pairing appeared normal at metaphase I, segregation...

Male meiosis in higher organisms features synchronous cell divisions a large number of cells. It is not clear how this synchrony achieved, nor it known whether the linked to regulation cycle progression. Here, we describe an Arabidopsis mutant, named tardy asynchronous (tam), that exhibits phenotype delayed and during male meiosis. In Arabidopsis, two nuclear occur before simultaneous cytokinesis yields tetrad haploid tam, are delayed, resulting formation abnormal intermediates, most...

Summary Cytokinin (CK) influences many aspects of plant growth and development, its function often involves intricate interactions with other phytohormones such as auxin ethylene. However, the molecular mechanisms underlying role CK regulators are still poorly understood. Here we describe isolation characterization Arabidopsis CK‐induced root curling 1 ( ckrc1 ) mutant. CKRC1 encodes a previously identified tryptophan aminotransferase (TAA1) involved in indole‐3‐pyruvic acid (IPA) pathway...

Normal flower development likely requires both specific and general regulators. We have isolated an Arabidopsis mutant ask1–1 (for -Arabidopsis skp1-like1–1), which exhibits defects in vegetative reproductive development. In the ask1–1mutant, rosette leaf growth is reduced, resulting smaller than normal leaves, internodes floral stem are shorter normal. Examination of cell sizes these organs indicates that expansion mutant, but number reduced. numbers petals stamens many flowers one or more...

Abstract Meiosis is often described as a special case of cell division since it differs from mitosis in having two nuclear divisions without an intervening S-phase. It will be great interest to uncover what molecular mechanisms underlie these features meiosis. We previously reported that the tardy asynchronous meiosis (tam) mutant Arabidopsis (Arabidopsis thaliana) slower cycle progression male Here we report TAM encodes A-type cyclin, CYCA1;2. The point mutation tam replaced conserved...

Amyloplasts are hypothesized to play a key role in the cellular mechanisms of gravity perception plants. While previous studies have examined effects starch deficiency on gravitropic sensitivity, this paper, we report gravitropism plants with greater amount relative normal wild type. Thus, studied sex1 ( s tarch ex cess) mutant Arabidopsis thaliana , which accumulates extra because it is defective protein involved regulation mobilization. Compared type (WT), seedlings contained excess...

Cellulases, hemicellulases, and pectinases play important roles in fruit development maturation. Although mutants with defects these processes have not been reported for cellulase or hemicellulase genes, the ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE1 (ADPG1) ADPG2 were previously shown to be essential silique dehiscence Arabidopsis (Arabidopsis thaliana). Here, we demonstrate that gene CELLULASE6 (CEL6) MANNANASE7 (MAN7) function of siliques. We found genes expressed both vegetative...

Formation of polyploid organisms by fertilization unreduced gametes in meiotic mutants is believed to be a common phenomenon species evolution. However, not well understood how nature generally exist as haploid and diploid long evolutionary time while polyploidization must have repeatedly occurred via mutations. Here, we show that the ploidy increased for two consecutive generations due but viable Arabidopsis cyclin a1;2-2 (also named tardy asynchronous meiosis-2) mutant, resultant octaploid...

Phenotypes are variable within species, with high phenotypic variation in the fitness and cell morphology of natural yeast strains due to genetic variation. A gene deletion collection laboratory also contains variations, demonstrating involvement each its specific function. However, date, no study has compared variations between mutants yeast. The morphological variance was 110 most distinct 36 typical using a generalized linear model. had higher than strains. Thirty-six conferred...

Background and AimsThe tam (tardy asynchronous meiosis) mutant of Arabidopsis thaliana, which exhibits a modified cytokinesis with switch from simultaneous to successive cytokinesis, was used perform direct test the implication in aperture-pattern ontogeny angiosperm pollen grains. The aperture pattern corresponds number arrangement apertures (areas wall permitting tube germination) on surface grain.

Abstract Formation of polyploid organisms by fertilization unreduced gametes in meiotic mutants is believed to be a common phenomenon species evolution. However, not well understood how nature generally exist as haploid and diploid long evolutionary time while polyploidization must have repeatedly occurred via mutations. Here, we show that the ploidy increased for two consecutive generations due but viable Arabidopsis cyclin a1;2‐2 (also named tardy asynchronousmeiosis‐2) mutant, resultant...

Abstract Spindle elongation is crucial to normal chromosome separation in eukaryotes; particular, it required for or associated with the extension of distance between spindle poles and further moving apart already separated chromosomes. However, little known about relationship status separation, unknown whether different organisms shares any quantitative feature. The Arabidopsisask1-1 mutant might be a unique material addressing these questions because appears have functional spindles, but...

Microbial fatty acids are synthesized by Type II acid synthase and could be tailored acyl-ACP thioesterase. With the prospects of medium-chain fatty-acid-derivative biofuels, selectivity thioesterase has been studied to control product chain length. Here, we report an alternative approach manipulating acyl carrier protein portion switch length propensity It was demonstrated that ChFatB2 from Cuphea hookeriana preferred C10-ACP C8-ACP with ACP E. coli, while converting preference lanceolate....

The Arabidopsis MYB transcriptional factors FOUR LIPS (FLP) and MYB88 are predicted to play a broader role than just limiting the number of guard cells per stoma in epidermis based on their expression patterns. Analysis numbers all epidermal cotyledons flp mutants flp-1 myb88 double mutant may substantiate functions FLP nonstomatal cells.The types abaxial mature were determined under different growth conditions flp-1, flp-3, flp-8, tmm-1 single mutants, accessions Columbia-0 (Col, control...

Abstract Dark-grown hypocotyls of a starch-deficient mutant (NS458) tobacco (Nicotiana sylvestris) lack amyloplasts and plastid sedimentation, have severely reduced gravitropism. However, gravitropism improved dramatically when NS458 seedlings were grown in the light. To determine extent this improvement whether contain sedimented amyloplasts, gravitropic sensitivity (induction time intermittent stimulation) size position endodermis measured for 8 d Light-grown but less sensitive than wild...

In Arabidopsis, loss-of-function mutations in the A-type cyclin CYCA1;2/TARDY ASYNCHRONOUS MEIOSIS (TAM) gene lead to production of abnormal meiotic products including triads and dyads. Here we report that overexpression TAM by ASK1:TAM transgene also led dyads meiosis, as well shriveled seeds, a dominant fashion. However, partial mutant tam-1, an line, wild type differed dynamic changes chromosome thread thickness from zygotene diplotene. We found pericentromeric heterochromatin regions...