The transition of mature pollen to the progamic phase represents an important step in the regulation of plant sexual reproduction. The progamic phase encompasses the initiation of pollen tube germination, growth of the pollen tube through the stigma (the silk in maize) and concludes with fertilization of the female gametophyte....
Maintaining genome integrity is essential for an organism, as mutation
accumulation can lead to cancer, reduced fitness, and heritable diseases in offspring.
Therefore the study of mutations, how they are induced, and how they are prevented is
vital. Biomonitor systems are useful for understanding the relevant biological effects
of a...
Plants develop a vast array of cell shapes and sizes by selectively modifying their surrounding cell walls to expand in some regions and not in others. This process of morphogenesis requires the delivery of secretory vesicles to specific locations at the cell periphery, where exocytosis adds new membrane and proteins...
Crown gall disease is an agricultural problem caused by the soil-borne bacterium, Agrobacterium tumefaciens. A. tumefaciens oncogenes cause transformed plant cells to overproduce the hormones, auxin and cytokinin. High hormone levels cause unorganized plant cell growth resulting in a gall. Control of crown gall disease is difficult because after plant...
Tocopherols are plant secondary metabolites that are known collectively as
vitamin E. Tocopherol compounds act as potent antioxidants by quenching free
radicals and protecting fatty acids from oxidative damage. In humans (in vivo)
tocopherols protect membrane lipids from breaking down, while in oils (in vitro)
tocopherols protect fatty acids from...
Beet yellows virus (BYV) is a filamentous, positive-strand RNA virus that belongs to the family Closteroviridae. BYV particles encapsidate a 15.5 kb RNA and posses complex polar architecture. A long virion body is formed by the major capsid protein(CP), whereas the minor capsid protein (CPm) assembles a short tail that...
Plant growth, development, and environmental responsiveness are
dependent on hormone-induced gene expression. This dissertation reports
multiple interactions between the plant hormones auxin and ethylene and
investigates their contribution to the gravitropic response, elongation
growth, adventitious root formation, callus and tracheary element initiation
and growth, and flower development.
Four mutants of...
The plant hormone auxin regulates many aspects of plant growth and
development. At the cellular level, auxin can stimulate cell division, cell elongation, and
cell differentiation. Little is known about the molecular mechanisms that mediate auxin
action at this level, although changes in gene expression have been implicated in each...
The phytohormones auxin and cytokinin control plant development through a complex network of interactions which include synergistic, additive, and opposite effects whose mechanisms are unknown. The auxin-insensitive diageotropica (dgt) mutant provided a tool to dissect the relationship between auxin- and cytokinin-induced responses in tomato. Morphological, physiological, and molecular data support...