Articles
APPLICATION OF MECHANO-DWARFING STIMULI TO ARABIDOPSIS FOR MUTANT-SCREEN DEVELOPMENT
Article number
618_8
Pages
85 – 93
Language
English
Abstract
Experiments were conducted to develop a mass application mechano-dwarfing screen of Arabidopsis thaliana seedlings in order to visually identify non-responding variants of a mutant population.
Various alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls.
Studies investigated effects of static impedance (perforated plates) or dynamic frictional contact and flexing (brushes) in both greenhouse and controlled growth environments.
Brush treatments were given twice daily, while plates were placed on flats overnight.
Treatment effects in both locations were compromised due to interactions of photosynthetic photon flux (PPF), growth medium, temperature, and nutritional factors.
Arabidopsis grown under low-PPF artificial light using a rockwool growth medium grew upright with limited leaf expansion, which enhanced mechano-responsiveness.
Fluorescent lamps alone (F) or fluorescent + incandescent (F+I) lighting regimes were tested for brush and plate treatments.
Hypocotyl elongation was reduced by twice-daily brush or plate treatments.
Under F lighting, brushed seedlings exhibited greater reduction in growth relative to undisturbed controls than did plate treatments.
Seedlings grown under F+I lamps also exhibited stress-induced growth reductions, but stressed seedlings lodged to a greater extent due to more hypocotyl elongation.
Temperature-response studies indicated increased hypocotyl elongation but decreased leaf expansion across the range of 20-28°C but decreased mechano-responsivity to brushing with increasing temperature.
Daylength studies indicated similar mechano-dwarfing of hypocotyls over the daylength range of 12-24 h, whereas fresh weight differences declined.
Environmental growth parameters for a reliable, visual mutant screen include low-PPF fluorescent lighting, ambient temperatures in the low-mid 20s (°C), and twice-daily brush treatments.
These system parameters will be used to screen T-DNA insertional mutant lines for TCH-gene knockouts.
Various alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls.
Studies investigated effects of static impedance (perforated plates) or dynamic frictional contact and flexing (brushes) in both greenhouse and controlled growth environments.
Brush treatments were given twice daily, while plates were placed on flats overnight.
Treatment effects in both locations were compromised due to interactions of photosynthetic photon flux (PPF), growth medium, temperature, and nutritional factors.
Arabidopsis grown under low-PPF artificial light using a rockwool growth medium grew upright with limited leaf expansion, which enhanced mechano-responsiveness.
Fluorescent lamps alone (F) or fluorescent + incandescent (F+I) lighting regimes were tested for brush and plate treatments.
Hypocotyl elongation was reduced by twice-daily brush or plate treatments.
Under F lighting, brushed seedlings exhibited greater reduction in growth relative to undisturbed controls than did plate treatments.
Seedlings grown under F+I lamps also exhibited stress-induced growth reductions, but stressed seedlings lodged to a greater extent due to more hypocotyl elongation.
Temperature-response studies indicated increased hypocotyl elongation but decreased leaf expansion across the range of 20-28°C but decreased mechano-responsivity to brushing with increasing temperature.
Daylength studies indicated similar mechano-dwarfing of hypocotyls over the daylength range of 12-24 h, whereas fresh weight differences declined.
Environmental growth parameters for a reliable, visual mutant screen include low-PPF fluorescent lighting, ambient temperatures in the low-mid 20s (°C), and twice-daily brush treatments.
These system parameters will be used to screen T-DNA insertional mutant lines for TCH-gene knockouts.
Authors
J.A. Montgomery, R.A. Bressan, C.A. Mitchell
Keywords
Brushing, hypocotyl, mechanical stress, photomorphogenesis, plate, PPF, temperature
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