Molecular cloning of a putative Acanthus ebracteatus- 9-cis-epoxycarotenoid deoxygenase (AeNCED) and its overexpression in rice

9-Cis-epoxycarotenoid dioxygenase (NCED) is an important enzyme which catalyzes the oxidative cleavage of abscisic acid (ABA), a plant growth regulator which plays a vital role in stress tolerance. In this study, a cDNA sequence encoding NCED from a mangrove plant (Acanthus ebracteatus) was analyzed and overexpressed in rice. Analysis of the deduced amino acid sequence of AeNCED revealed an open reading frame of 1,638 bp encoding a protein of 545 amino acids, with a 123 bp 5’-untranslated region (UTR) and a 259 bp 3’-UTR. The deduced amino acid sequence of AeNCED is more than 80% identical to the amino acid sequences of carotenoid cleavage dioxygenase from carrot, tomato, and coffee. The RNA encoding AeNCED was detected in transgenic rice (Oryza sativa cv. BRRI dhan29) plants overexpressing this cDNA. These plants only showed significantly higher tolerance to salinity at germination and better performance at seedling stages. The levels of ABA in transgenic rice seedlings overexpressing AeNCED treated with 100 mM NaCl for 24 hours were higher than those of untransformed plants. However, a higher level of dihydrophaseic acid (DPA) and ABA glucose ester (ABA-GE) were also observed in these transgenic plants suggesting that rapid degradation of ABA through a self-regulation mechanism

A novel strigolactone-miR156 module controls stomatal behaviour during drought recovery

miR156 is a conserved microRNA whose role and induction mechanisms under stress are poorly known. Strigolactones are phytohormones needed in shoots for drought acclimation. They promote stomatal closure ABA-dependently and independently; however, downstream effectors for the former have not been identified. Linkage between miR156 and strigolactones under stress has not been reported. We compared ABA accumulation and sensitivity as well as performances of wt and miR156-overexpressing (miR156-oe) tomato plants during drought. We also quantified miR156 levels in wt, strigolactone-depleted and strigolactone-treated plants, exposed to drought stress. Under irrigated conditions, miR156 overexpression and strigolactone treatment led to lower stomatal conductance and higher ABA sensitivity. Exogenous strigolactones were sufficient for miR156 accumulation in leaves, while endogenous strigolactones were required for miR156 induction by drought. The “after-effect” of drought, by which stomata do not completely re-open after rewatering, was enhanced by both strigolactones and miR156. The transcript profiles of several miR156 targets were altered in strigolactone-depleted plants. Our results show that strigolactones act as a molecular link between drought and miR156 in tomato, and identify miR156 as a mediator of ABA-dependent effect of strigolactones on the after effect of drought on stomata. Thus, we provide insights into both strigolactone and miR156 action on stomata

Gibberellin–Abscisic Acid Balances during Arbuscular Mycorrhiza Formation in Tomato

Plant hormones have become appropriate candidates for driving functional plant mycorrhization programs, including the processes that regulate the formation of arbuscules in arbuscular mycorrhizal (AM) symbiosis. Here, we examine the role played by ABA/GA interactions regulating the formation of AM in tomato. We report differences in ABA and GA metabolism between control and mycorrhizal roots. Active synthesis and catabolism of ABA occur in AM roots. GAs level increases as a consequence of a symbiosis-induced mechanism that requires functional arbuscules which in turn is dependent on a functional ABA pathway. A negative interaction in their metabolism has been demonstrated. ABA attenuates GA-biosynthetic and increases GA-catabolic gene expression leading to a reduction in bioactive GAs. Vice versa, GA activated ABA catabolism mainly in mycorrhizal roots. The negative impact of GA3 on arbuscule abundance in wild-type plants is partially offset by treatment with ABA and the application of a GA biosynthesis inhibitor rescued the arbuscule abundance in the ABA-deficient sitiens mutant. These findings, coupled with the evidence that ABA application leads to reduce bioactive GA1, support the hypothesis that ABA could act modifying bioactive GA level to regulate AM. Taken together, our results suggest that these hormones perform essential functions and antagonize each other by oppositely regulating AM formation in tomato roots.This study was supported by grants from the Comisión Interministerial de Ciencia y Tecnología (CICYT) and Fondos Europeos de Desarrollo Regional (FEDER) through the Ministerio de Economía y Competitividad in Spain (AGL2008-00742; AGL2011-25930) as well as the Junta de Andalucía (Research Group BIO 260). JM-R was supported by a research fellowship from the FPU-MICINN program. The work on hormone measurements was funded by a Grant Agency of the Czech Republic (grant no. 14-34792S) and by the Ministry of Education, Youth and Sports of the Czech Republic through the National Program for Sustainability I (Nr. LO1204).Peer reviewedPeer Reviewe

Distinct hormonal and morphological control of dormancy and germination in Chenopodium album dimorphic seeds

Dormancy and heteromorphism are innate seed properties that control germination timing through adaptation to the prevailing environment. The degree of variation in dormancy depth within a seed population differs considerably depending on the genotype and maternal environment. Dormancy is therefore a key trait of annual weeds to time seedling emergence across seasons. Seed heteromorphism, the production of distinct seed morphs (in color, mass or other morphological characteristics) on the same individual plant, is considered to be a bet-hedging strategy in unpredictable environments. Heteromorphic species evolved independently in several plant families and the distinct seed morphs provide an additional degree of variation. Here we conducted a comparative morphological and molecular analysis of the dimorphic seeds (black and brown) of the Amaranthaceae weed Chenopodium album. Freshly harvested black and brown seeds differed in their dormancy and germination responses to ambient temperature. The black seed morph of seedlot #1 was dormant and 2/3rd of the seed population had non-deep physiological dormancy which was released by after-ripening (AR) or gibberellin (GA) treatment. The deeper dormancy of the remaining 1/3rd non-germinating seeds required in addition ethylene and nitrate for its release. The black seeds of seedlot #2 and the brown seed morphs of both seedlots were non-dormant with 2/3rd of the seeds germinating in the fresh mature state. The dimorphic seeds and seedlots differed in testa (outer seed coat) thickness in that thick testas of black seeds of seedlot #1 conferred coat-imposed dormancy. The dimorphic seeds and seedlots differed in their abscisic acid (ABA) and GA contents in the dry state and during imbibition in that GA biosynthesis was highest in brown seeds and ABA degradation was faster in seedlot #2. Chenopodium genes for GA and ABA metabolism were identified and their distinct transcript expression patterns were quantified in dry and imbibed C. album seeds. Phylogenetic analyses of the Amaranthaceae sequences revealed a high proportion of expanded gene families within the Chenopodium genus. The identified hormonal, molecular and morphological mechanisms and dormancy variation of the dimorphic seeds of C. album and other Amaranthaceae are compared and discussed as adaptations to variable and stressful environments

<i>DELAY OF GERMINATION 1</i> mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses showthat thismechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperature-dependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancymechanismprovides a highly adaptable temperature-sensing mechanism to control the timing of germination.</p

XXV. mezinárodní kolokvium o regionálních vědách

Title in English: 25th International Colloquium on Regional Sciences: Conference proceedings The conference proceedings consists of papers presented at the 25th International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 57 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism, or regional public administration

XXIV. mezinárodní kolokvium o regionálních vědách

Title in English: 24th International Colloquium on Regional Sciences: Conference proceedings. The conference proceedings consists of papers presented at the 24rd International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 79 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism or regional public administration

Financial and tax specifics in an international advertising agency

The aim of this thesis is to describe financial accounting in existing advertising agency, which has to report financial information to parent company placed in USA. The parent company use the US GAAP principles and prepares consolidated financial statements for all the comapnies in the group

Já truchlivý bůh - literature template and movie

Práce se zabývá komparací povídky a filmu Já truchlivý bůh. Dále mapuje přerod Milana Kundery v romanopisce, jenž si svou cestu vyšlapal skrze poezii, dramata a také povídky. Samostatná kapitola je věnovaná rozboru Směšných lásek. V následující části práce je podrobně rozebírána povídka a následně také film. Na konci našeho počínání je umístěno závěrečné zhodnocení, které mapuje výsledný dojem z provedeného porovnávání obou děl.Katedra českého jazyka a literaturyObhájenoThis work deals with the comparison of the short story and film named Já truchlivý bůh (I, the Mournful God). This work also maps the transformation of Milan Kundera into a prose writer, who made his way through the poetry, drama and short stories. A separate chapter is dedicated the analysis of Směšné lásky (Laughable Loves). The story and the film were analyzed in the next part of the work. The final resume is placed at the end of this work and presents the result of this comparison