Somatic embryogenesis was initiated in C. sativus L. from shoot meristems on LS medium containing BAP (2×10-5 M)+NAA (2×10-5 M). Various stages of somatic embryogenesis were observed in the same medium and the development was asynchronous. Somatic embryo development proceeded through well recognized sequences (globular to embryoids) with clearly discernible bipolar regions. Matured embryos coul...

Introduction Plants are modular organisms that develop by the repetition of elementary botanical entities or constructional units through the three main and fundamental morphogenetic processes of growth, branching and reiteration (Barthélémy and Caraglio, 2007). Repetition of these entities induces gradual or abrupt changes in their characteristics. These characteristics are quantified through ...

Almost all of the tissue in a mature plant is ultimately derived from specialized groups of cells, called meristems, that reside at the tips of roots and shoots. Shoot apical meristems (SAMs) are responsible for elaborating the above ground portions of the plant, which include stems, leaves and flowers, whereas root apical meristems generate the extensive underground network of roots necessary ...

Cymes and racemes form two broad types of inflorescence architecture. Racemes are monopodial and bear axillary flowers, but in cymes the main stem ends in an apical flower and is continued sympodially by a series of lateral shoots. In these shoots floral identity is delayed by a previously unknown mechanism. We show that the MADS-box transcription factor EXTRAPETALS (EXP) transiently represses ...

Most plant organs develop from meristems. Rice FON1, which is an ortholog of Clv1, regulates stem cell proliferation and organ initiation. The point muta-tions, fon1-1 and fon1-2, disrupt meristem balance, resulting in alteration of floral organ numbers and the architecture of primary rachis branches. In this study, we identified two knockout alleles, fon1-3 and fon1-4, generated by T-DNA and T...

Three D-cyclin genes are expressed in the apical meristems of snapdragon (Antirrhinum majus). The cyclin D1 and D3b genes are expressed throughout meristems, whereas cyclin D3a is restricted to the peripheral region of the meristem, especially the organ primordia. During floral development, cyclin D3b expression is: (a) locally modulated in the cells immediately surrounding the base of organ pr...

Two methods to induce a symptomless infection of crown rot (Phytophthora cactorum) in stolons of three strawberry (Fragaria×ananassa) cultivars were evaluated. Spraying a 10−4 ml zoospore suspension was the most effective method, producing a mean infection rate of 12%. Meristem cultures were subsequently established from all of the inoculated stolons and tested eight weeks later for the presenc...

In angiosperms, individual lateral organs and whole flowers may develop asymmetrically along their dorsoventral axes. Dorsoventral asymmetry of Antirrhinum leaves requires activity of the Phantastica gene and other factors acting redundantly with it. We describe the effects of a mutation in the Handlebars gene, identified as an enhancer of the phantastica mutant phenotype. Genetic analysis sugg...

Plant growth and development are sustained by continuous cell division in the meristems, which is perturbed by various environmental stresses. For the maintenance of meristematic functions, it is essential that cell division be coordinated with cell differentiation. However, it is unknown how the proliferative activities of the meristems and the coordination between cell division and differenti...

A sensitive and dynamically responsive auxin signaling reporter based on the DII domain of the INDOLE-3-ACETIC ACID28 (IAA28, DII) protein from Arabidopsis (Arabidopsis thaliana) was modified for use in maize (Zea mays). The DII domain was fused to a yellow fluorescent protein and a nuclear localization sequence to simplify quantitative nuclear fluorescence signal. DII degradation dynamics prov...