Shoot and floral meristem activity in higher plants is controlled by complex signaling networks consisting of positive and negative regulators. The Arabidopsis ULTRAPETALA1 (ULT1) gene has been shown to act as a negative regulator of meristem cell accumulation in inflorescence and floral meristems, as loss-of-function ult1 mutations cause inflorescence meristem enlargement, the production of ex...

The control of organ growth by coordinating cell proliferation and differentiation is a fundamental developmental process. In plants, postembryonic root growth is sustained by the root meristem. For maintenance of root meristem size, the rate of cell differentiation must equal the rate of cell division. Cytokinin and auxin interact to affect the cell proliferation and differentiation balance an...

The shoot apical meristem contains a pool of undifferentiated stem cells and generates all above-ground organs of the plant. During vegetative growth, cells differentiate from the meristem to initiate leaves while the pool of meristematic cells is preserved; this balance is determined in part by genetic regulatory mechanisms. To assess vegetative meristem growth and genetic control in Zea mays,...

The shoot apical meristem contains cells that undergo continual growth and division to generate the building blocks for the aerial portion of the plant. As cells leave the meristem, they undergo differentiation to form specific cell types. Most notably, heterotrophic cells of the meristem rapidly gain autotrophic capability by synthesis and assembly of components of the chloroplast. At the same...

Axillary shoot formation is a key determinant of plant architecture. Formation of the axillary shoot is regulated by initiation of the axillary meristem or outgrowth of the axillary bud. Here, we show that rice (Oryza sativa) TILLERS ABSENT1 (TAB1; also known as Os WUS), an ortholog of Arabidopsis thaliana WUS, is required to initiate axillary meristem development. We found that formation of th...

The genus Dipsacus is characterized by a remarkable bidirectional flowering sequence and a rare phyllotactic pattern. Considering that flower initiation and flowering sequence may be interconnected, we document the development of the head meristem in Dipsacus fullonum. Our results indicate a gradual change in the geometry of the head meristem beginning with a dome shaped stage, continuing with ...

Development in higher plants is characterized by the reiterative formation of lateral organs from the flanks of shoot apical meristems. Because organs are produced continuously throughout the life cycle, the shoot apical meristem must maintain a pluripotent stem cell population. These two tasks are accomplished within separate functional domains of the apical meristem. These functional domains ...

The shoot apical meristem generates stem, leaves, and lateral shoot meristems during the entire shoot ontogeny. Vegetative leaves are generated by the meristem in the vegetative developmental phase, while in the reproductive phase either bracts subtending lateral flower primordia (or paraclades), or perianth and strictly reproductive organs are formed. Meristem growth is fully characterized by ...

HAIRY MERISTEM (HAM) proteins, members of the GRAS family of transcriptional regulators, are essential for maintenance of indeterminate growth in flowering plant shoots, loss-of-function ham mutants exhibiting a strikingly novel phenotype of shoot meristem arrest and differentiation. Specific cellular/molecular functions of HAM proteins underlying meristem maintenance are unknown. In this revie...

potato virus y (pvy) and potato leafroll virus (plrv) are two major viruses which reduce 10-90 percent of yield and quality of potato tubers. in the present study, the efficiency of different methods, including meristem culture, thermotherapy followed by meristem culture and electerotherapy followed by meristem culture in two cultivars (agria and marfona) infected by plrv or pvy were evaluated....