Apical meristems are small embryogenic regions, located at the tip of plant axes, that build up plant organs by cellular division. The production of the meristems depends on their internal physical, physiological and genetic state and is controled by contextual factors (like microenvironment, availability of nutrients, etc.). In principle, the number of variables that may be used to define the ...

Reproductive meristems of the hooded (KK) genotype of barley at the stage of young lemma primordia were injected with the inhibitors sodium azide, hydrazine, and hydroxylamine at concentrations of 10(-3), 10(-4), and 10(-5)M, as well as with phenylboric acid. These treatments all brought about an altered expression of the adult phenotype in the direction of awned (kk) genotype. Analysis of tiss...

The variety of plant architectures observed in nature is predominantly determined by vegetative and reproductive branching patterns, the positioning of lateral organs, and differential stem elongation. Branches, lateral organs, and stems are the final products of the activity of meristems, groups of stem cells whose function is genetically determined and environmentally influenced. Several deca...

This work establishes that cessation of root elongation of intact squash (Cucurbita pepo L.) plants is an early result of boron deficiency. Root elongation is slowed by 6 hours and is virtually stopped as early as 24 hours after boron is first withheld from the nutrient solution. As root elongation ceased, cell elongation progressed distally into the region normally occupied by the apical meris...

The alkaloids such as caffeine and nicotine, which are constantly consumed by humans, were proved to be harmful for the plants also. These alkaloids alter the biological activity of living organism and lead to disturbances in the environmental sustainability within the ecosystem. So, the present literature explicates the comparative toxicity of both caffeine and nicotine in root meristems of La...

In plants, transposable elements (TEs) are kept inactive by transcriptional gene silencing (TGS). TGS is established and perpetuated by RNA-directed DNA methylation (RdDM) and maintenance methylation pathways, respectively. Here, we describe a novel RdDM function specific for shoot apical meristems that reinforces silencing of TEs during early vegetative growth. In meristems, RdDM counteracts d...

Meristems require a myriad of intercellular signaling pathways for coordination of cell division within and between functional zones and clonal cell layers. This control of cell division ensures a constant availability of stem cells throughout the life span of the meristem while limiting overproliferation of meristematic cells and maintaining the meristem structure. We have undertaken a genetic...

The formation of axillary meristems in leaf axils is a prerequisite for the development of lateral shoots, which largely contribute to plant architecture. Several transcription factor-encoding genes, including CUC3, RAX, LAS, LOF1, and ROX, have been cloned by screening for axillary meristem mutants in Arabidopsis thaliana. These genes will facilitate our understanding of the mechanisms underly...