151 research outputs found
Hubungan Antara Tingkat Pengetahuan Remaja Tentang Seksualitas Dengan Sikap Terhadap Seksual Pranikah Pada Siswa Kelas X Di Smk Kasatrian Solo Kartasura Sukoharjo
Remaja dalam memasuki masa peralihan tanpa pengetahuan yang memadai tentang seksual pranikah. Hal ini disebabkan orang tua merasa tabu membicarakan masalah seksual dengan anaknya dan hubungan orang tua anak menjadi jauh sehingga anak berpaling ke sumber-sumber lain yang tidak akurat khususnya
teman. Perilaku seks pranikah pada kalangan pelajar pada saat ini sudah banyak terjadi termasuk pada pelajar di kota Solo. Hal ini tidak terlepas bebasnya pergaulan antar teman yang berlainan jenis. Perilaku seksual pranikah terjadi salahsatu penyebabnya adalah masih rendahnya pengetahuan secara baik pada siswa mengenai seksualitas. Kurangnya pengetahuan ini mengakibatkan sikap yang negatif siswa tentang seks pranikah. Tujuan penelitian ini adalah mengetahuai hubungan Antara Tingkat Pengetahuan remaja tentang seksualitas dengan sikap terhadap seksual pranikah pada siswa kelas X Di SMK Kasatrian Solo-Sukoharjo.
Metode penelitian ini menggunakan observational analitik dengan rancangan penelitian menggunakan cross sectional. Sampel penelitian sebanyak 137 siswa Kelas X Di SMK Kasatrian, dengan teknik pengambilan sampel menggunakan
proportional random sampling. Instrument penelitian berupa kuesioner pengetahuan tentang seksualitas dan kuesioner sikap tentang seksual pranikah.
Alat analisis data menggunakan uji Chi Square. Hasil penelitian diketahui 23responden (16.8%) dengan pengetahuan tinggi, 60 responden (43,8%) dengan
pengetahuan sedang dan 54 siswa (39,4%) dengan pengetahuan yang rendah. Sikap responden tetang seks pranikah diketahui 59 responden (43,1%) dengan sikap positif dan 78 responden (56,9%) dengan sikap negative. Berdasarkan hasil
uji statistic Chi Square diperoleh nilai χ2 = 8.677, dengan p = 0,013, sehinggadisimpulkan adahubungan antara tingkat pengetahuan remaja tentang seksualitas dengan sikap terhadap seks pranikah pada siswa kelas X di SMK Kasatrian Solo Kartasura Sukoharjo
Functional conservation of MADS-box factors controlling floral organ identity in rice and Arabidopsis
Studies on MADS-box genes in Arabidopsis and other higher eudicotyledonous flowering plants have shown that they are key regulators of flower development. Since Arabidopsis and monocotyledonous rice are distantly related plant species it is interesting to investigate whether the floral organ identity factors have been conserved in their functions, and if not, to understand the differences. Arabidopsis and rice are very suitable for these studies since they are both regarded as models for plant functional genomics. Both their genomes are sequenced and tools are available for the analysis of gene function. These developments have accelerated experiments and increased our knowledge on rice gene function. Therefore it is the right moment to perform a comparative analysis on MADS-box factors controlling floral organ identity as reported in this review
Reversible male sterility in eggplant
SummarySince decades, plant male sterility is considered a powerful tool for biological containment to minimize unwanted self‐pollination for hybrid seed production. Furthermore, prevention of pollen dispersal also answers to concerns regarding transgene flow via pollen from Genetically Modified (GM) crops to traditional crop fields or wild relatives. We induced male sterility by suppressing endogenous general transcription factor genes, TAFs, using anther‐specific promoters combined with artificial microRNA (amiRNA) technology (Schwab et al., 2006). The system was made reversible by the ethanol inducible expression of an amiRNA‐insensitive form of the target gene. We provide proof of concept in eggplant, a cultivated crop belonging to the Solanaceae family that includes many important food crops. The transgenic eggplants that we generated are completely male sterile and fertility can be fully restored by short treatments with ethanol, confirming the efficiency but also the reliability of the system in view of open field cultivation. By combining this system with induced parthenocarpy (Rotino et al., 1997), we provide a novel example of complete transgene containment in eggplant, which enables biological mitigation measures for the benefit of coexistence or biosafety purposes for GM crop cultivation
The Arabidopsis TFIID factor AtTAF6 controls pollen tube growth
AbstractInitiation of transcription mediated by RNA polymerase II requires a number of transcription factors among which TFIID is the major core promoter recognition factor. TFIID is composed of highly conserved factors which include the TATA-binding protein (TBP) and about 14 TBP-associated factors (TAFs). Recently, the complete Arabidopsis TAF family has been identified. To obtain functional information about Arabidopsis TAFs, we analyzed a T-DNA insertion mutant for AtTAF6. Segregation analysis showed that plants homozygous for the mutant allele were never found, indicating that inhibition of the AtTAF6 function is lethal. Genetic experiments also revealed that the male gametophyte was affected by the attaf6 mutation since significant reduced transmission of the mutant allele through the male gametophyte was observed. Detailed histological and morphological analysis showed that the T-DNA insertion in AtTAF6 specifically affects pollen tube growth, indicating that the transcriptional regulation of only a specific subset of genes is controlled by this basal transcription factor
Interactions between FLORAL ORGAN NUMBER₄ and floral homeotic genes in regulating rice flower development
The floral meristem (FM) is self-maintaining at the early stages of flower development, but it is terminated when a fixed number of floral organs are produced. The FLORAL ORGAN NUMBER4 (FON4; also known as FON2) gene, an ortholog of Arabidopsis CLAVATA3 (CLV3), is required for regulating FM size and determinacy in rice. However, its interactions with floral homeotic genes remain unknown. Here, we report the genetic interactions between FON4 and floral homeotic genes OsMADS15 (an A-class gene), OsMADS16 (also called SUPERWOMAN1, SPW1, a B-class gene), OsMADS3 and OsMADS58 (C-class genes), OsMADS13 (a D-class gene), and OsMADS1 (an E-class gene) during flower development. We observed an additive phenotype in the fon4 double mutant with the OsMADS15 mutant allele dep (degenerative palea). The effect on the organ number of whorl 2 was enhanced in fon4 spw1. Double mutant combinations of fon4 with osmads3, osmads58, osmads13, and osmads1 displayed enhanced defects in FM determinacy and identity, respectively, indicating that FON4 and these genes synergistically control FM activity. In addition, the expression patterns of all the genes besides OsMADS13 had no obvious change in the fon4 mutant. This work reveals how the meristem maintenance gene FON4 genetically interacts with C, D, and E floral homeotic genes in specifying FM activity in monocot rice.Wei Xu, Juhong Tao, Mingjiao Chen, Ludovico Dreni, Zhijing Luo, Yun Hu, Wanqi Liang and Dabing Zhan
Molecular control of carpel development in the grass family
Carpel is the ovule-bearing female reproductive organ of flowering plants and is required to ensure its protection, an efficient fertilization, and the development of diversified types of fruits, thereby it is a vital element of most food crops. The origin and morphological changes of the carpel are key to the evolution and adaption of angiosperms. Progresses have been made in elucidating the developmental mechanisms of carpel establishment in the model eudicot plant Arabidopsis thaliana, while little and fragmentary information is known in grasses, a family that includes many important crops such as rice (Oryza sativa), maize (Zea mays), barley (Hordeum vulgare), and wheat (Triticum aestivum). Here, we highlight recent advances in understanding the mechanisms underlying potential pathways of carpel development in grasses, including carpel identity determination, morphogenesis, and floral meristem determinacy. The known role of transcription factors, hormones, and miRNAs during grass carpel formation is summarized and compared with the extensively studied eudicot model plant Arabidopsis. The genetic and molecular aspects of carpel development that are conserved or diverged between grasses and eudicots are therefore discussed.Chaoqun Shen, Gang Li, Ludovico Dreni and Dabing Zhan
Transcriptome analysis reveals rice MADS13 as an important repressor of the carpel development pathway in ovules
In angiosperms, floral homeotic genes encoding MADS-domain transcription factors regulate the development of floral organs. Specifically, members of the SEPALLATA (SEP) and AGAMOUS (AG) subfamilies form higher-order protein complexes to control floral meristem determinacy and to specify the identity of female reproductive organs. In rice, the AG subfamily gene OsMADS13 is intimately involved in the determination of ovule identity, since knock-out mutant plants develop carpel-like structures in place of ovules, resulting in female sterility. Little is known about the regulatory pathways at the base of rice gynoecium development. To investigate molecular mechanisms acting downstream of OsMADS13, we obtained transcriptomes of immature inflorescences from wild-type and Osmads13 mutant plants. Among a total of 476 differentially expressed genes (DEGs), a substantial overlap with DEGs from the SEP-family Osmads1 mutant was found, suggesting that OsMADS1 and OsMADS13 may act on a common set of target genes. Expression studies and preliminary analyses of two up-regulated genes encoding Zinc-finger transcription factors indicated that our dataset represents a valuable resource for the identification of both OsMADS13 target genes and novel players in rice ovule development. Taken together, our study suggests that OsMADS13 is an important repressor of the carpel pathway during ovule development
ERAMOSA controls lateral branching in snapdragon
Plant forms display a wide variety of architectures, depending on the number of lateral branches, internode elongation and phyllotaxy. These are in turn determined by the number, the position and the fate of the Axillary Meristems (AMs). Mutants that affect AM determination during the vegetative phase have been isolated in several model plants. Among these genes, the GRAS transcription factor LATERAL SUPPRESSOR (Ls) plays a pivotal role in AM determination during the vegetative phase. Hereby we characterize the phylogenetic orthologue of Ls in Antirrhinum, ERAMOSA (ERA). Our data supported ERA control of AM formation during both the vegetative and the reproductive phase in snapdragon. A phylogenetic analysis combined with an analysis of the synteny of Ls in several species strongly supported the hypothesis that ERA is a phylogenetic orthologue of Ls, although it plays a broader role. During the reproductive phase ERA promotes the establishment of the stem niche at the bract axis but, after the reproductive transition, it is antagonized by the MADS box transcription factor SQUAMOSA (SQUA). Surprisingly double mutant era squa plants display a squa phenotype developing axillary meristems, which can eventually turn into inflorescences or flowers
Rice MADS6 interacts with the floral homeotic genes SUPERWOMAN1, MADS3, MADS58, MADS13, and DROOPING LEAF in specifying floral organ identities and meristem fate
AGAMOUS-LIKE6 (AGL6) genes play essential roles in flower development, but whether and how they work with floral organ identity genes remain less understood. Here, we describe interactions of the rice (Oryza sativa) AGL6 gene MADS6 with other rice floral homeotic genes in flower development. Genetic analyses revealed that MADS6 specifies the identity of the three inner whorls and floral meristem determinacy redundantly with SUPERWOMAN1/MADS16 (B-gene) or MADS3 (C-gene). MADS6 was shown to define carpel/ovule development and floral determinacy by interacting with MADS13 (D-gene) and control the palea and floral meristem identities together with the YABBY gene DROOPING LEAF. Expression analyses revealed that the transcript levels of six B-, C-, and E-class genes were reduced in mads6-1 at the early flower developmental stage, suggesting that MADS6 is a key regulator of early flower development. Moreover, MADS6 can directly bind to a putative regulatory motif on MADS58 (C-gene), and mads6-1 mads58 displayed phenotypes similar to that of mads6-1. These results suggest that MADS6 is a key player in specifying flower development via interacting with other floral homeotic genes in rice, thus providing new insights into the mechanism by which flower development is controlled.Haifeng Li, Wanqi Liang, Yun Hu, Lu Zhu, Changsong Yin, Jie Xu, Ludovico Dreni, Martin M. Kater, and Dabing Zhan
Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots
[EN] The C-function, according to the ABC model of floral organ identity, is required for stamen and carpel development and to provide floral meristem determinacy. Members of the AG lineage of the large MADS box gene family specify the C-function in a broadly conserved manner in angiosperms. In core eudicots, two sub-lineages co-exist, euAG and PLE, which have been extensively characterized in Antirrhinum majus and Arabidopsis thaliana, where strong sub-functionalization has led to highly divergent contributions of the respective paralogs to the C-function. Various scenarios have been proposed to reconstruct the evolutionary history of the euAG and PLE lineages in eudicots, but detailed functional analyses of the roles of these genes in additional representative species to validate evolutionary hypotheses are scarce. Here, we report functional characterization of euAG- and PLE-like genes in Nicotiana benthamiana through expression analyses and phenotypic characterization of the defects caused by their specific down-regulation. We show that both paralogs redundantly contribute to the C-function in this species, providing insights on the likely evolution of these gene lineages following divergence of the major groups within the eudicots (rosids and asterids). Moreover, we have demonstrated a conserved role for the PLE-like genes in controlling fruit dehiscence, which strongly supports the ancestral role of PLE-like genes in late fruit development and suggests a common evolutionary origin of late developmental processes in dry (dehiscent) and fleshy (ripening) fruits.We thank Rafael Martinez-Pardo and Eugenio Grau for technical support, Amy Litt (New York Botanical Gradens, Bronx, NY, USA) for providing VIGS plasmids, Eugenio Minguet for help with the LFY matrix and Morpheus tool, and Francisco Madueno, Monica Colombo and Barbara Ambrose (NYBG) for critical reading of the manuscript. The work was funded by grant BIO2009-09920 from the Spanish Ministerio de Ciencia e Innovacion to C.F.Fourquin, C.; Ferrandiz Maestre, C. (2012). Functional analyses of AGAMOUS family members in Nicotiana benthamiana clarify the evolution of early and late roles of C-function genes in eudicots. Plant Journal. 71(6):990-1001. https://doi.org/10.1111/j.1365-313X.2012.05046.xS990100171
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