Přednáška z Anatomie a fyziologie rostlin
| datum |
23.4.2013 |
| přednáší |
Dr. David W. Lawlor (Rothamsted Reserach, U.K.) |
| název |
Genetic Engineering to Improve Plant Performance under Drought: Physiological Evaluation of
Achievements, Limitations and Possibilities
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| anotace |
Fully drought resistant (DR) crop plants would be beneficial but have not been produced
by selection-breeding. Genetic modification (GM) of several species (Arabidopsis, rice, oil-seed
rape, maize) by introduction of very many genes is claimed to have given DR. The physiological
responses of GM plants to water deficits, the mechanisms and consequences and claims are evaluated.
Definitions of DR, methods of assessing it and type of DR resulting from GM are presented and
explained. GM plants, grown in soil, develop stress symptoms later than the wild-type (WT) when
watering is stopped, due to their slower total water loss caused by smaller total leaf area (LA) and/
or decreased stomatal conductance (gs), associated with thicker laminae (denser mesophyll and
smaller cells). Slower water loss, combined with non-linear soil water characteristics, results in later
development of stress symptoms in GM cf to WT plants. Rewatering WT and GM plants when the
GM become stressed results in faster and better recovery of the GM and is taken to show DR and that
mechanisms targeted are assumed responsible. However, the methods do not allow proper comparison
and so claims that GM alters metabolism giving DR are uncritical: experimental tests are suggested.
Small LA and gs may not decrease productivity in well-watered plants in the laboratory, but may
in the field. Optimisation of traits to environment is required in field-trails of GM oilseed rape and
maize. Current evidence suggests that GM plants may not be more `DR’ than selection-bred cultivars.
Článek v Journal of Experimental Botany
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| materiály |
životopis přednášejícího (PDF)
pozvánka (PDF)
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