Symposia of the Society for Experimental Biology最新文献_第9页

The regulation of flowering time by daylength in Arabidopsis. 拟南芥开花时间的日长调控。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

G Coupland, M I Igeño, R Simon, R Schaffer, G Murtas, P Reeves, F Robson, M Piñeiro, M Costa, K Lee, P Suárez-López

{"title":"The regulation of flowering time by daylength in Arabidopsis.","authors":"G Coupland, M I Igeño, R Simon, R Schaffer, G Murtas, P Reeves, F Robson, M Piñeiro, M Costa, K Lee, P Suárez-López","doi":"","DOIUrl":"","url":null,"abstract":"We are studying several Arabidopsis mutants that show altered regulation of flowering time in response to daylength. One of the mutations we are studying, constans, delays flowering under long days but has no effect under short days. Analysis of the expression of the CONSTANS gene, and modification of its expression in transgenic plants, suggests that this gene promotes flowering in response to long days and that the delay in flowering that occurs in wild-type plants under short days is at least in part due to regulation of CONSTANS gene transcription. We describe genetic approaches that we are taking to identify genes that act in the same genetic pathway as CONSTANS, and in particular the relationship between CONSTANS and two other genes that we are studying. These are LATE ELONGATED HYPOCOTYL, for which we have a dominant mutant allele that causes late flowering, and EARLY SHORT DAYS 4, whose inactivation causes early flowering. In addition to their effects on flowering time, the over-expression of CONSTANS and the inactivation of EARLY SHORT DAYS 4 cause the Arabidopsis shoot to become determinate and therefore to terminate development prematurely. This phenotype is discussed in light of other genes that have previously been shown to be required to maintain indeterminate development of the shoot.","PeriodicalId":22134,"journal":{"name":"Symposia of the Society for Experimental Biology","volume":"51 ","pages":"105-10"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21500650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Methylation controls the low temperature induction of flowering in Arabidopsis. 甲基化控制拟南芥低温开花诱导。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

E S Dennis, P Bilodeau, J Burn, E J Finnegan, R Genger, C Helliwell, B J Kang, C C Sheldon, W J Peacock

{"title":"Methylation controls the low temperature induction of flowering in Arabidopsis.","authors":"E S Dennis, P Bilodeau, J Burn, E J Finnegan, R Genger, C Helliwell, B J Kang, C C Sheldon, W J Peacock","doi":"","DOIUrl":"","url":null,"abstract":"Control of the transition to flowering is critical for reproductive success of a plant. Studies in Arabidopsis have led us to suggest how this species has harnessed the environmental cue of a period of low temperature to ensure flowering occurs at an appropriate time. We propose that Arabidopsis has both vernalization-independent and vernalization-dependent pathways for the initiation of inflorescence development in the shoot apex. The vernalization-independent pathway may be concerned with the supply of carbohydrate to the shoot apex. In late flowering ecotypes which respond to vernalization the vernalization-independent pathway is blocked by the action of two dominant repressors of flowering, FRI and FLC, which interact to produce very late flowering plants which respond strongly to vernalization. We have isolated a gene which may correspond to FLC. We suggest the vernalization-dependent pathway, which may be concerned with apical GA biosynthesis, is blocked by methylation of a gene critical for flowering. This gene may correspond to that encoding kaurenoic acid hydroxylase (KAH), an enzyme catalysing a step in the GA biosynthetic pathway. Under this scheme vernalization causes unblocking of this pathway by demethylation possibly of the KAH gene and consequent biosynthesis of active GAs in the apex.","PeriodicalId":22134,"journal":{"name":"Symposia of the Society for Experimental Biology","volume":"51 ","pages":"97-103"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21500649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light control of Arabidopsis developmental pattern. 拟南芥发育模式的光控制。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

X W Deng

引用次数: 0

Cell fate in plants. Lessons from the Arabidopsis root. 植物中的细胞命运。从拟南芥的根部得到的教训。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

L Dolan, P Linstead, C Kidner, K Boudonck, X F Cao, F Berger

{"title":"Cell fate in plants. Lessons from the Arabidopsis root.","authors":"L Dolan, P Linstead, C Kidner, K Boudonck, X F Cao, F Berger","doi":"","DOIUrl":"","url":null,"abstract":"Classical studies in plant development have indicated that the fate of plant cells is fixed late, after cell division has ceased. Earlier commitment events are therefore considered reversible. To gain a mechanisatic understanding of the processes involved in specification and fixation of cell fate in plants, we are using the Arabidopsis root epidermis as a model system. The Arabidopsis root epidermis is composed of two cell types whose pattern of differentiation is directed by positional cues during development. Examination of mutations has identified genes involved in the establishment of cell fate specification in this tissue. TRANSPARENT TESTA GLABRA (TTG) and GLABRA2 (GL2) are positive regulators of non-hair fate and are active during the early differentiation of the epidermis in the meristem. GL2 encodes a homeobox protein which is expressed in non-hair cells in the meristem and is positively regulated by TTG. Mutations in genes involved in the regulation of ethylene biosynthesis and signal transduction indicate that ethylene is a positive regulator of hair cell fate. Treatment of ttg and gl2 plants with modulators of ethylene biosynthesis indicate that ethylene acts down stream of TTG and GL2 during the fate specification process. The relationship between meristem organisation and the mechanism underpinning the establishment of cell fate in other systems is also discussed.","PeriodicalId":22134,"journal":{"name":"Symposia of the Society for Experimental Biology","volume":"51 ","pages":"11-7"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21500837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Specificity of acyltransferases and their genetic manipulation for environmental adaptation and development of new industrial oils. 酰基转移酶的特异性及其基因操作对新型工业油脂的环境适应性和开发。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

A R Slabas, C L Brough

引用次数: 0

The evolution of grass genome organisation and function. 草地基因组组织与功能的进化。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

J L Bennetzen

{"title":"The evolution of grass genome organisation and function.","authors":"J L Bennetzen","doi":"","DOIUrl":"","url":null,"abstract":"New cloning technologies and more efficient DNA sequencing now permit comprehensive structural studies of complex eukaryotic genomes. Previous global investigations of genome organisation in plants had shown that abundant repetitive DNAs were intermixed with genes. However, the nature of the major repeats, their possible biological roles, their origins, and their precise patterns of organisation were not clearly defined. My laboratory has used large clones derived from homologous regions of the maize, sorghum and rice genomes to investigate the nature, functional properties and evolution of grass genome organisation. Unexpectedly simple patterns of genome composition and arrangement have been seen, and these appear to be similar in different grasses. Our detailed studies of the maize genome indicate that short (2-20 kb) blocks of gene-containing DNA alternate with large (2-200 kb) blocks of intermixed middle and highly repetitive DNAs. Most of the highly repetitive sequences, and many of the middle repetitive DNAs, are retrotransposons that have inserted within each other. These repetitive DNAs are usually methylated and mostly inactive, but they are homologous to transcripts found in many different tissues. The unmethylated DNA is composed primarily of genes interspersed with lower-copy-number retroelements and inverted-repeat transposable elements. Gene order and sequence are highly conserved, but the mobile DNAs between genes appear to be different due to their rapid evolution and their variable presence or locations in different grasses.","PeriodicalId":22134,"journal":{"name":"Symposia of the Society for Experimental Biology","volume":"51 ","pages":"123-6"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21500653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Maize as a model system for investigating the molecular basis of morphological evolution in plants. 玉米作为研究植物形态进化分子基础的模式系统。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

J Doebley

引用次数: 0

Antirrhinum and Asteridae--evolutionary changes of floral symmetry. 天鼻草和菊科——花对称的进化变化。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

P K Endress

{"title":"Antirrhinum and Asteridae--evolutionary changes of floral symmetry.","authors":"P K Endress","doi":"","DOIUrl":"","url":null,"abstract":"Lamiales s.l., a prominent clade in the Asteridae, commonly have pentamerous monosymmetric flowers with the upper (odd) stamen reduced or lacking. Of the five largest families of the Lamiales s.l. (Gesneriaceae, Scrophulariaceae, Bignoniaceae, Acanthaceae, and Verbenaceae/Lamiaceae), perhaps the most phylogenetically basal, the Gesneriaceae, is the only one with odd staminodes or stamens occurring in all genera. In addition, Gesneriaceae have relatively large odd staminodes often with a differentiation in filament and reduced anther. They also have the largest proportion of genera (approx. 8%) with more or less polysymmetric flowers with five fertile stamens. In the more advanced families of the Lamiales s.l. the pattern varies. In Bignoniaceae an odd staminode is also commonly present. The traditional Scrophulariaceae is the most diverse family with some tribes constantly having an odd staminode (e.g. Antirrhineae) and others missing it (e.g. Manuleae, Pedicularieae), reflecting its probable polyphyly. In Acanthaceae, and still more in Verbenaceae/Lamiaceae with their extremely monosymmetric flowers an odd staminode is more often missing than present. From the systematic distribution of the different floral forms it is most likely that monosymmetric flowers were already present at the base of the Lamiales s.l. but 'reversal' to polysymmetry was still easy in the basal groups with only weak expression of monosymmetry. The evolution of more pronounced monosymmetry proceeded in different lineages and loss of the odd stamen occurred in various clades. The developmentally most intriguing groups are those with loss of the perianth and reduction of floral organ numbers to two or one, Callitriche being the most extreme genus.","PeriodicalId":22134,"journal":{"name":"Symposia of the Society for Experimental Biology","volume":"51 ","pages":"133-40"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21500655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

SPINDLY's role in the gibberellin response pathway. SPINDLY在赤霉素反应途径中的作用。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

S E Jacobsen, N E Olszewski, E M Meyerowitz

引用次数: 0

The phytochromes: photosensory perception and signal transduction. 光敏色素:光感觉知觉和信号转导。

Symposia of the Society for Experimental Biology Pub Date : 1998-01-01

C D Fairchild, P H Quail

引用次数: 0