Download Free B And C Class Mads Box Genes And The Developmental Genetics Of Maize Flower Development Book in PDF and EPUB Free Download. You can read online B And C Class Mads Box Genes And The Developmental Genetics Of Maize Flower Development and write the review.

The ABC model of flower development describes how a flower is patterned and the genes necessary for floral organ identity. However, it is not clear that the ABC model can be generally applied to the flowering plants, as it was based solely on genetic studies from the core eudicot species Arabidopsis and Antirrhinum. This dissertation describes an examination of maize orthologs of B and C class genes, and compares their function with B and C class genes of Arabidopsis to understand the degree to which the ABC model is conserved. B class genes from maize were found to rescue Arabidopsis B class mutants, and the maize B class proteins were shown to bind DNA as an obligate heterodimer as has been demonstrated in Arabidopsis. These findings indicate conservation in biochemical function of the maize and Arabidopsis B class proteins. Furthermore, these findings support the conclusion that the lodicule, a grass specific organ of uncertain homology, represents a modified petal. A comparative expression approach was used to further verify the relationship of lodicules to the organs of non-grass flowers. B class genes were shown to be expressed in a whorl of foliar organs outside the stamens in Streptochaeta, a basal grass that diverged before the evolution of lodicules, and in the petals of the outgroup species Joinvillea and Chondropetalum strongly supporting the interpretation that lodicules are modified petals, and further supporting conservation of B class function between Arabidopsis and maize. Zag1 and Zmm2 are duplicate pair of C class genes from maize that are hypothesized to have partitioned the C class function of establishing stamen and carpel identity. Rescue of the Arabidopsis C class mutant ag with the two maize genes confirms that their protein products have subfunctionalized, with ZAG1 better able to promote carpel identity, and ZMM2 better able to promote stamen identity. A more recent duplicate of Zmm2 was isolated, Zmm23, as were mutant alleles of zmm2 and zmm23. While the zmm2 zmm23 double mutant had no phenotype, the zag1 zmm2 zmm23 showed a considerable enhancement of the previously described zag1 phenotype substantiating a C class function for Zmm2 and Zmm23.
Current major interests in this area include the study of higher level phylogenetic relationships and character evolution in the angiosperms, floral evolution, the genetic basis of key floral differences in basal angiosperms, the genetic and genomic consequences of polyploid speciation, conservation genetics of rare plant species, and phylogeography. Developmental Genetics of the Flower provides a series of papers focused on the developmental genetics of flowering as well as the genetic control of the timing of flowering. Investigation of speciational mechanisms, evolutionary relationships, and character evolution in flowering plants and land plants utilizing a variety of experimental approaches are discussed. The chapters are excellent reviews of the current fast-moving area of research. Provides a brief review of genes known to regulate flower development Articles emphasize the classic ABC model of flower development
Petunia belongs to the family of the Solanaceae and as such is closely related to important crop species like tomato, potato, eggplant, pepper and tobacco. With around 35 species described it is one of the smaller genera and among those there are two groups of species that make up the majority of them: the purple flowered P.integrifolia group and the white flowered P.axillaris group. It is assumed that interspecific hybrids between members of these two groups have laid the foundation for the huge variation in cultivars as selected from the 1830’s onwards. Petunia thus has been a commercially important ornamental since the early days of horticulture. Despite that, Petunia was in use as a research model only parsimoniously until the late fifties of the last century. By then seed companies started to fund academic research, initially with the main aim to develop new color varieties. Besides a moment of glory around 1980 (being elected a promising model system, just prior to the Arabidopsis boom), Petunia has long been a system in the shadow. Up to the early eighties no more then five groups developed classical and biochemical genetics, almost exclusively on flower color genes. Then from the early eighties onward, interest has slowly been growing and nowadays some 20-25 academic groups around the world are using Petunia as their main model system for a variety of research purposes, while a number of smaller and larger companies are developing further new varieties. At present the system is gaining credibility for a number of reasons, a very important one being that it is now generally realized that only comparative biology will reveal the real roots of evolutionary development of processes like pollination syndromes, floral development, scent emission, seed survival strategies and the like. As a system to work with, Petunia combines advantages from several other model species: it is easy to grow, sets abundant seeds, while self- and cross pollination is easy; its lifecycle is four months from seed to seed; plants can be grown very densely, in 1 cm2 plugs and can be rescued easily upon flowering, which makes even huge selection plots easy to handle. Its flowers (and indeed leaves) are relatively large and thus obtaining biochemical samples is no problem. Moreover, transformation and regeneration from leaf disc or protoplast are long established and easy-to-perform procedures. On top of this easiness in culture, Petunia harbors an endogenous, very active transposable element system, which is being used to great advantage in both forward and reverse genetics screens. The virtues of Petunia as a model system have only partly been highlighted. In a first monograph, edited by K. Sink and published in 1984, the emphasis was mainly on taxonomy, morphology, classical and biochemical genetics, cytogenetics, physiology and a number of topical subjects. At that time, little molecular data was available. Taking into account that that first monograph will be offered electronically as a supplement in this upcoming edition, we would like to put the overall emphasis for the second edition on molecular developments and on comparative issues. To this end we propose the underneath set up, where chapters will be brief and topical. Each chapter will present the historical setting of its subject, the comparison with other systems (if available) and the unique progress as made in Petunia. We expect that the second edition of the Petunia monograph will draw a broad readership both in academia and industry and hope that it will contribute to a further expansion in research on this wonderful Solanaceae.
MADS-box transcription factors are important regulators of flower development in all flowering plants. In the grasses, flowers (called florets) are contained in spikelets. Maize spikelets contain two florets (the upper and lower florets) that are morphologically identical, although development of the lower floret is delayed compared to the upper floret. Floral meristems are groups of undifferentiated cells that give rise to floral organs. bearded-ear (bde) encodes a MADS-box transcription factor required for multiple aspects of floral development. bde mutants affect the upper and lower florets differently, suggesting the gene regulatory network in the upper and lower floral meristems are different. In addition, two other MADS-box transcription factors (zmm8 and zmm14), are expressed only in the upper floral meristem (UFM), but not in the lower floral meristem (LFM). Together, these data suggest that the gene regulatory networks in the UFM and LFM are distinct and some genes, including MADS-box genes are differentially expressed. The long-term goal of this research is to globally identify genes specifically expressed in the UFM and LFM. Floral meristems cannot be manually dissected, so we are using laser capture microdissection (LCM) to specifically isolate UFM and LFM. LCM allows specific cells to be isolated from fixed, sectioned tissue using a laser. This tissue can then be used for downstream applications, including RNA isolation. The goal of this project is to isolate UFM and LFM using LCM and test for the expression of maize MADS-box transcription factors using RT-PCR and qPCR. I have optimized fixation and RNA isolation protocols for LCM, and we have isolated RNA from sectioned tissue. In addition, we have successfully isolated UFM and LFM from sectioned tissue using LCM, and extracted RNA for amplification. We have tested for the expression of several control genes using quantitative RT-PCR (qRT-PCR). zmm8 and zmm14, which were initially thought to be expressed exclusively in the UFM, were observed in the LFM albeit at much lower levels. Other spikelet meristem genes like ids1 and bd1 were also expressed in the UFM and LFM. However, ra1 and ra2, which are expressed in the SPM and in the anlagen of the SM were not observed in the mixed meristems (MM) containing a mixture floral meristems and spikelet meristems or the UFM and LFM. Pepcase1 and zmTIP2-3, which are expressed in the leaves and roots respectively were not observed in any floral meristems. qRT-PCR results showed that expression of zmm8 and zmm14 in the LFM is much lower than in the UFM. zmMADS3 was observed in both UFM and LFM but there was no significant difference in levels of expression in the two floral meristems. Together, these data suggests differential gene expression in the UFM and LFM may be studied by looking at the expression level of genes in the two floral meristems and not simply by looking at the absence or presence of a gene.
A benchmark text, Developmental Genetics and Plant Evolution integrates the recent revolution in the molecular-developmental genetics of plants with mainstream evolutionary thought. It reflects the increasing cooperation between strongly genomics-influenced researchers, with their strong grasp of technology, and evolutionary morphogenetists and sys
Handbook of Maize: Its Biology centers on the past, present and future of maize as a model for plant science research and crop improvement. The book includes brief, focused chapters from the foremost maize experts and features a succinct collection of informative images representing the maize germplasm collection.
MicroRNAs constitute a particularly important class of small RNAs given their abundance, broad phylogenetic conservation and strong regulatory effects, with plant miRNAs uniquely divulging their ancient evolutionary origins and their strong post-transcriptional regulatory effects. In Plant MicroRNAs: Methods and Protocols, experts in the field present chapters that focus on the identification, validation, and characterization of the miRNA class of RNAs, and address important aspects about heterochromatic small interfering RNAs. In addition, the methods contained in this volume emphasize miRNA analyses, but also include ways to distinguish one class of small RNAs from another. As a volume in the highly successful Methods in Molecular BiologyTM series, chapters include brief introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easy to use, Plant MicroRNAs: Methods and Protocols provides the research community with a set of protocols that will help advance vital miRNA research for all plant species, both in typical model species and non-model species alike.