Regulation of Cell Division and Growth in Roots of Lactuca sativa L. Seedlings by the Ent-Kaurene Diterpenoid Rabdosin B

Abstract

Rabdosin B, an ent-kaurene diterpenoid purified from the air-dried aerial parts of Isodon japonica (Burm.f) Hara var. galaucocalyx (maxin) Hara, showed a biphasic, dose-dependent effect on root growth and a strong inhibitory effect on root hair development in lettuce seedlings (Lactuca sativa L.). Lower concentrations of rabdosin B (20-80 microM) significantly promoted root growth, but its higher levels at 120-200 microM, by contrast, had inhibitory effects. Additionally, all tested concentrations (10-40 microM) inhibited root hair development of seedlings in a dose-dependent manner. Further investigations on the underlying mechanism revealed that the promotion effect of rabdosin B at the lower concentrations resulted from increasing the cell length in the mature region and enhancing the mitotic activity of meristematic cells in seedlings' root tips. In contrast, rabdosin B at higher concentrations inhibited root growth by affecting both cell length in the mature region and division of meristematic cells. Comet assay and cell cycle analysis demonstrated that the decrease of mitotic activity of root meristematic cells was due to DNA damage induced cell cycle retardation of the G(2) phase and S phase at different times.

Fitotoxicidade do chumbo na germinação e crescimento inicial de alface em função da anatomia radicular e ciclo celular.

“…A alface (Lactuca sativa L. -Asteraceae) tem sido amplamente utilizada em testes de fitotoxicidade (DING et al, 2009) e genotoxicidade (MONTEIRO et al, 2009;EOM et al, 2007) devido à sua sensibilidade e representatividade, e ainda por ser amplamente cultivada no mundo todo. De acordo com Campos et al (2008) a avaliação de danos sobre o complemento cromossômico da alface é favorecida pelo fato da espécie possuir características citogenéticas estáveis e bem definidas, como cromossomos grandes e em número reduzido (2n = 2x = 18).…”

Infraspecific variations in essential oil and glandular trichomes in Nepeta heliotropifolia

“…It seems that infraspecific variations in the essential oil compositions have adaptive value for plants. Ding et al (2010) stated the compositions of essential oil are also involved in a variety of ecological interactions, such as allelopathy. It is a mechanism of biochemical interaction between plant-plant, plant-microbe, plant-insect or plantherbivore (Alipour and Saharkhiz 2016).…”

Overexpression of OsDPR, a novel rice gene highly expressed under iron deficiency, suppresses plant growth

“…These two processes play essential roles in the determination of plant size [13]. The growth-limiting effects of various kinds of stress have been related to their effects on the regulation of elongation and cell division [10]. As shown above, the OsDPR-transgenic plants exhibited reduced size of aerial parts, as well as shortened roots.…”

“…The phenotype showed that the shoots and roots of transformants were shorter than those of wild-type plants, which suggested that OsDPR is associated with plant growth regulation. The growth-repression effects of various kinds of factors can be related to the regulation of cell expansion or cell division [10]. In the present study, we examined both the size of cells in transgenic tobacco plants and cell proliferation of transformed BY-2 cells.…”