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At least 523 records · Page 29Linked to original sources
PubMed2005

Plant meristems: mobile mediators of cell fate.

How do transcription factors control the fates of cells that express them? One class of plant transcription factors has recently been shown to function by regulating the synthesis of cytokinin and gibberellin hormones--mobile molecules more usually associated with long-distance signalling.

Arabidopsis↗
PubMed2004

Determination of cell fate in apical meristems.

Although roots and shoots exhibit profound differences in their pattern of organogenesis, both apices share the capacity for indeterminate growth. Ongoing molecular and genetic analyses have revealed relatively little overlap between the genes that regulate organogenesis in the root and shoot apices. In the shoot, an ensemble of transcription factors lays the foundations for the leaf, in which indeterminacy is exchanged for more limited and polarized growth. Class-I KNOX genes are downregulated in the anlagen of the leaf early in its establishment, but are maintained in other regions of the shoot apex. This persistent expression of KNOX genes may serve to prevent the precocious determination of apical initial derivatives, and thus may allow the production of a large number of pluripotent cells from a relatively small number of stem cells. Greater commonality between roots and shoots is seen in mechanisms that underlie histogenesis and radial-patterning processes. Recent work suggests that undetermined stem cells in both the root and the shoot may be maintained by related mechanisms, which feature regulation of WUSCHEL-like organizer activities by feedback mechanisms that involve receptor-like kinases.

Gene Expression Regulation, Plant↗
PubMed2005

Cell proliferation patterns at the shoot apical meristem.

The highly stereotypic cell proliferation patterns in many plant species suggest that the strict control of the cell cycle in time and space is an essential basis for ordered development. At the same time, conflicting evidence contradicts this view, indicating that cell division simply follows growth patterns that are dictated by the local availability of nutrients. Recent evidence shows that there is no strict hierarchical relationship between growth and proliferation. Cell expansion and proliferation, for example, are controlled by the same regulators. Cell proliferation depends on nutrient distribution but, in turn, the use of the same nutrients depends on the activity of cell cycle regulators such as E2F transcription factors.

Arabidopsis↗
PubMed2006

CLE peptide ligands and their roles in establishing meristems.

Research in the past decade revealed that peptide ligands, also called peptide hormones, play a crucial role in intercellular communication and defense response in plants. Recent studies demonstrated that a family of plant-specific genes, CLAVATA3 (CLV3)/ENDOSPERM SURROUNDING REGION (ESR) (CLE), which has at least 31 members in Arabidopsis genome, are able to generate extracellular peptides to regulate cell division and differentiation. A hydroxyl 12-amino acid peptide derived from the conserved CLE motif of CLV3 promotes cell differentiation, whereas another CLE-derived peptide suppresses the differentiation. These peptides probably interact with membrane-bound, leucine-rich repeat receptor-like kinases (LRR-RLKs) to execute the decision between cell proliferation and differentiation.

Ligands↗
PubMed2001

Plant meristems: a ménage à trois to end it all.

Regulated termination of stem cell maintenance is required to complete reproductive development in plants. Two recent studies have revealed a new relationship for some old suspects; the WUSCHEL gene, which promotes indeterminancy, is involved as well as the floral regulators LEAFY and AGAMOUS.

AGAMOUS Protein, Arabidopsis↗
PubMed2001

The role of floral meristems in patterning.

The flower is one of the most complex and varied structures found in plants. Over the past decade, we have begun to understand how floral patterning is established in a handful of model species. Recent studies have identified the presence of several potential pathways for organ patterning. Many genes that are involved in these pathways have been cloned, providing opportunities for further fruitful investigations into the genetic components of flower development.

Magnoliopsida↗