Targeted single-cell gene induction by optimizing the dually regulated CRE/ system by a newly defined heat-shock promoter and the steroid hormone in .

Multicellular organisms rely on intercellular communication systems to organize their cellular functions. In studies focusing on intercellular communication, the key experimental techniques include the generation of chimeric tissue using transgenic DNA recombination systems represented by the CRE/ system. If an experimental system enables the induction of chimeras at highly targeted cell(s), it will facilitate the reproducibility and precision of experiments.

Redox feedback regulation of ANAC089 signaling alters seed germination and stress response.

The interplay between the phytohormone abscisic acid (ABA) and the gasotransmitter nitric oxide (NO) regulates seed germination and post-germinative seedling growth. We show that GAP1 (germination in ABA and cPTIO 1) encodes the transcription factor ANAC089 with a critical membrane-bound domain and extranuclear localization. ANAC089 mutants lacking the membrane-tethered domain display insensitivity to ABA, salt, and osmotic and cold stresses, revealing a repressor function.

S-nitrosylation triggers ABI5 degradation to promote seed germination and seedling growth.

Plant survival depends on seed germination and progression through post-germinative developmental checkpoints. These processes are controlled by the stress phytohormone abscisic acid (ABA). ABA regulates the basic leucine zipper transcriptional factor ABI5, a central hub of growth repression, while the reactive nitrogen molecule nitric oxide (NO) counteracts ABA during seed germination.

Requirement of MIR165A primary transcript sequence for its activity pattern in Arabidopsis leaf primordia.

miRNAs might move cell to cell and act as mobile signals in plant development, while the regulatory mechanisms of miRNA cell-to-cell movement are still unclear. Recently, in Arabidopsis leaf primordia, we revealed that miR165 from the MIR165A gene, which is expressed in the abaxial epidermal cells of leaf primordia, acts non-cell-autonomously in inner cells on the abaxial side. We proposed that not only mature miR165 sequence but also the MIR165A primary transcript sequence are required for the confinement of miR165 activity to the abaxial side of leaf primordia.

Mutations in Plastidial 5-Aminolevulinic Acid Biosynthesis Genes Suppress a Pleiotropic Defect in Shoot Development of a Mitochondrial GABA Shunt Mutant in Arabidopsis.

Plant developmental processes are co-ordinated with the status of cell metabolism, not only in mitochondria but also in plastids. In Arabidopsis thaliana, succinic semialdehyde (SSA), a GABA shunt metabolite, links the specific mitochondrial metabolic pathway to shoot development. To understand the mechanism of SSA-mediated development, we isolated a succinic semialdehyde dehydrogenase (ssadh) suppressor mutant, affected in its ability to catalyze SSA to succinic acid.

A molecular mechanism that confines the activity pattern of miR165 in Arabidopsis leaf primordia.

In Arabidopsis leaf primordia, the expression of HD-Zip III, which promotes tissue differentiation on the adaxial side of the leaf primordia, is repressed by miRNA165/166 (miR165/166). Small RNAs, including miRNAs, can move from cell to cell. In this study, HD-Zip III expression was strikingly repressed by miR165/166 in the epidermis and parenchyma cells on the abaxial side of the leaf primordia compared with those on the adaxial side.

The Half-Size ABC Transporter FOLDED PETALS 2/ABCG13 Is Involved in Petal Elongation through Narrow Spaces in Arabidopsis thaliana Floral Buds.

Flowers are vital for attracting pollinators to plants and in horticulture for humans. Petal morphogenesis is a central process of floral development. Petal development can be divided into three main processes: the establishment of organ identity in a concentric pattern, primordia initiation at fixed positions within a whorl, and morphogenesis, which includes petal elongation through the narrow spaces within the bud.

Pattern dynamics in adaxial-abaxial specific gene expression are modulated by a plastid retrograde signal during Arabidopsis thaliana leaf development.

The maintenance and reformation of gene expression domains are the basis for the morphogenic processes of multicellular systems. In a leaf primordium of Arabidopsis thaliana, the expression of FILAMENTOUS FLOWER (FIL) and the activity of the microRNA miR165/166 are specific to the abaxial side. This miR165/166 activity restricts the target gene expression to the adaxial side.

Precocious progression of tissue maturation instructs basipetal initiation of leaflets in Chelidonium majus subsp. asiaticum (Papaveraceae).

Premise Of The Study: On a compound leaf, leaflet primordia are repetitively formed along the apical-basal axis, with the direction varying among taxa. Why and how the directions vary among species is yet to be solved, although a change in a single factor was proposed to cause the variation. In this study, we compared two species in the Papaveraceae with different directions of leaflet initiation, Chelidonium majus subsp.

Physical interaction of floral organs controls petal morphogenesis in Arabidopsis.

Flowering plants bear beautiful flowers to attract pollinators. Petals are the most variable organs in flowering plants, with their color, fragrance, and shape. In Arabidopsis (Arabidopsis thaliana), petal primordia arise at a similar time to stamen primordia and elongate at later stages through the narrow space between anthers and sepals.

A comprehensive expression analysis of the Arabidopsis MICRORNA165/6 gene family during embryogenesis reveals a conserved role in meristem specification and a non-cell-autonomous function.

One of the most fundamental events in plant ontogeny is the specification of the shoot and root apical meristem (SAM and RAM) in embryogenesis. In Arabidopsis, the restricted expression of class III homeodomain leucine zipper (HD-ZIP III) transcription factors (TFs) at the central-apical domain of early embryos is required for the correct specification of the SAM and RAM. Because the expression of HD-ZIP III TFs is suppressed by microRNA165/166 (miR165/6), elucidation of the sites of miR165/6 production and their activity range is a key to understanding the molecular basis of SAM and RAM specification in embryogenesis.

Tissue-specific transcriptome analysis reveals cell wall metabolism, flavonol biosynthesis and defense responses are activated in the endosperm of germinating Arabidopsis thaliana seeds.

Seed germination is a result of the competition of embryonic growth potential and mechanical constraint by surrounding tissues such as the endosperm. To understand the processes occurring in the endosperm during germination, we analyzed tiling array expression data on dissected endosperm and embryo from 6 and 24 h-imbibed Arabidopsis seeds. The genes preferentially expressed in the endosperm of both 6 and 24 h-imbibed seeds were enriched for those related to cell wall biosynthesis/modifications, flavonol biosynthesis, defense responses and cellular transport.

Succinic semialdehyde dehydrogenase is involved in the robust patterning of Arabidopsis leaves along the adaxial-abaxial axis.

Polarity along the adaxial-abaxial axis of the leaf is essential for leaf development and morphogenesis. One of the genes that encodes a putative transcription factor regulating adaxial-abaxial polarity, FILAMENTOUS FLOWER (FIL), is expressed in the abaxial region of the leaf primordia. However, the molecular mechanisms controlling the polarized expression of FIL remain unclear.

Nitrate responses of Arabidopsis cho1 mutants: obvious only when excess nitrate is supplied.

We reported a loss-of-function of an Arabidopsis double AP2 transcription factor CHOTTO1 (CHO1) gene results in the altered responses to high concentrations of nitrate (approximately 50 mM). Nitrate up to 10 mM promotes growth of the wildtype seedling, but inhibits it under higher concentrations. The cho1 seedlings responded to nitrate up to 10 mM similarly to the wildtype, but the inhibitory effect of excess nitrate is less prominent in the mutants.

Genome-wide analysis of endogenous abscisic acid-mediated transcription in dry and imbibed seeds of Arabidopsis using tiling arrays.

The phytohormone abscisic acid (ABA) plays important roles in the induction and maintenance of seed dormancy. Although application of exogenous ABA inhibits germination, the effects of exogenous ABA on ABA-mediated gene transcription differ from those of endogenous ABA. To understand how endogenous ABA regulates the transcriptomes in seeds, we performed comprehensive expression analyses using whole-genome Affymetrix tiling arrays in two ABA metabolism mutants - an ABA-deficient mutant (aba2) and an ABA over-accumulation mutant (cyp707a1a2a3 triple mutant).

Temporal expression patterns of hormone metabolism genes during imbibition of Arabidopsis thaliana seeds: a comparative study on dormant and non-dormant accessions.

Seed imbibition is a prerequisite for subsequent dormancy and germination control. Here, we investigated imbibition responses of Arabidopsis seeds by transcriptomic and hormone profile analyses using dormant [Cape Verde Islands (Cvi)] and non-dormant [Columbia (Col)] accessions. Once imbibed, seeds of both accessions swelled most up to 3 h, reflecting water uptake.

Co-regulation of ribosomal protein genes as an indicator of growth status: Comparative transcriptome analysis on axillary shoots and seeds in Arabidopsis.

Plant growth is regulated by internal and external cues using a limited number of genes coded in the genome. Comparative transcriptome analysis often provides an indication of which particular sets of genes are co-regulated in different physiological events. We have recently reported that protein synthesis-related genes were highly overrepresented in the genes upregulated during germination in Arabidopsis.

CHOTTO1, a double AP2 domain protein of Arabidopsis thaliana, regulates germination and seedling growth under excess supply of glucose and nitrate.

Arabidopsis chotto1 (cho1) mutants show resistance to (-)-R-ABA, an ABA analog, during germination and seedling growth. Here, we report cloning and characterization of the CHO1 gene. cho1 mutants showed only subtle resistance to (+)-S-ABA during germination.

The Arabidopsis abscisic acid catabolic gene CYP707A2 plays a key role in nitrate control of seed dormancy.

Nitrate releases seed dormancy in Arabidopsis (Arabidopsis thaliana) Columbia accession seeds in part by reducing abscisic acid (ABA) levels. Nitrate led to lower levels of ABA in imbibed seeds when included in the germination medium (exogenous nitrate). Nitrate also reduced ABA levels in dry seeds when provided to the mother plant during seed development (endogenous nitrate).

Phytochrome- and gibberellin-mediated regulation of abscisic acid metabolism during germination of photoblastic lettuce seeds.

Germination of lettuce (Lactuca sativa) 'Grand Rapids' seeds is regulated by phytochrome. The action of phytochrome includes alterations in the levels of gibberellin (GA) and abscisic acid (ABA). To determine the molecular mechanism of phytochrome regulation of ABA metabolism, we isolated four lettuce cDNAs encoding 9-cis-epoxycarotenoid dioxygenase (biosynthesis; LsNCED1-LsNCED4) and four cDNAs for ABA 8'-hydroxylase (catabolism; LsABA8ox1-LsABA8ox4).

Transcription factor AtTCP14 regulates embryonic growth potential during seed germination in Arabidopsis thaliana.

To understand the molecular mechanisms underlying regulation of seed germination, we searched enriched cis elements in the upstream regions of Arabidopsis genes whose transcript levels increased during seed germination. Using available published microarray data, we found that two cis elements, Up1 or Up2, which regulate outgrowth of Arabidopsis axillary shoots, were significantly over-represented. Classification of Up1- and Up2-containing genes by gene ontology revealed that protein synthesis-related genes, especially ribosomal protein genes, were highly over-represented.

Identification of cis-elements that regulate gene expression during initiation of axillary bud outgrowth in Arabidopsis.

Growth regulation associated with dormancy is an essential element in plant life cycles. To reveal regulatory mechanisms of bud outgrowth, we analyzed transcriptomes of axillary shoots before and after main stem decapitation in Arabidopsis (Arabidopsis thaliana). We searched for any enriched motifs among the upstream regions of up-regulated and down-regulated genes after decapitation.

Disruption and overexpression of auxin response factor 8 gene of Arabidopsis affect hypocotyl elongation and root growth habit, indicating its possible involvement in auxin homeostasis in light condition.

Auxin response factor (ARF) family genes play a central role in controlling sensitivity to the plant hormone auxin. We characterized the function of ARF8 in Arabidopsis by investigating a T-DNA insertion line (arf8-1) and overexpression lines (ARF8 OX) of ARF8. arf8-1 showed a long-hypocotyl phenotype in either white, blue, red or far-red light conditions, in contrast to ARF8 OX that displayed short hypocotyls in the light.

MASSUGU2 encodes Aux/IAA19, an auxin-regulated protein that functions together with the transcriptional activator NPH4/ARF7 to regulate differential growth responses of hypocotyl and formation of lateral roots in Arabidopsis thaliana.

We have isolated a dominant, auxin-insensitive mutant of Arabidopsis thaliana, massugu2 (msg2), that displays neither hypocotyl gravitropism nor phototropism, fails to maintain an apical hook as an etiolated seedling, and is defective in lateral root formation. Yet other aspects of growth and development of msg2 plants are almost normal. These characteristics of msg2 are similar to those of another auxin-insensitive mutant, non-phototropic hypocotyl4 (nph4), which is a loss-of-function mutant of AUXIN RESPONSE FACTOR7 (ARF7) (Harper et al.