Il gene Osmyb4 di riso, codificante per un fattore transcrizionale, si è dimostrato efficiente nella protezione a diversi stress abiotici in diverse specie vegetali, sebbene il grado di tolleranza ai diversi stress dipende dalla specie vegetale in esame. Sono state prodotte otto linee transgeniche di orzo, esprimenti il gene Osmyb4 sotto il controllo del promotore di Arabidopsis, cor15a inducibile da freddo, per valutare l'efficienza di detto gene in orzo. Dopo test preliminari, le linee con miglior performance sono state sottoposte a test di congelamento a -11 e -12 °C. La tolleranza è stata valutata misurando i parametri FV/FM. Tre linee transgeniche mostrano un aumento significativo della tolleranza. Tali linee mostrano anche un miglior vigore germinativo in condizioni di freddo e ipossia. In tali condizioni (freddo/ipossia) tali linee transgeniche mostrano un metabolismo modificato come dimostrato dall'attività di geni chiave coinvolti nella risposta a stress anossico. I risultati indicano che l'espressione indotta da freddo del gene Osmyb4 in orzo può migliorare efficacemente la tolleranza al congelamento e il vigore germinativo a freddo senza effetti deleteri sulla crescita delle piante.
[object Object] The Osmyb4 rice gene, coding for a transcription factor, proved to be efficient against different abiotic stresses as a trans(cis)gene in several plant species, although the effectiveness was dependent on the host genomic background. Eight barley transgenic lines carrying the rice Osmyb4 gene under the control of the Arabidopsis cold inducible promoter cor15a were produced to test the efficiency of this gene in barley. After a preliminary test, the best performing lines were subjected to freezing at-11°C and -12°C. Frost tolerance was assessed measured the Fv/Fm parameter widely used to indicate the maximum quantum yield of photosystem II photochemistry in the dark adapted state. Three transgenic lines showed significantly increased tolerance. These selected lines were further studied under a complex stress applying cold and hypoxia at germinating stage. In these conditions the three selected transgenic lines outperformed the wild type barley in terms of germination vigour. The transgenic plants also showed a significant modification of their metabolism under cold/hypoxia conditions as demonstrated through the assessment of the activity of key enzymes involved in anoxic stress response. None of the transgenic lines showed dwarfism, just a slight retarded growth. These results provide evidence that the cold dependent expression of Osmyb4 can efficiently improved frost tolerance and germination vigour at low temperature without deleterious effect on plant growth.
The rice Osmyb4 gene enhances tolerance to frost and improves germination under unfavourable conditions in transgenic barley plants
Coraggio I;
2012
Abstract
[object Object] The Osmyb4 rice gene, coding for a transcription factor, proved to be efficient against different abiotic stresses as a trans(cis)gene in several plant species, although the effectiveness was dependent on the host genomic background. Eight barley transgenic lines carrying the rice Osmyb4 gene under the control of the Arabidopsis cold inducible promoter cor15a were produced to test the efficiency of this gene in barley. After a preliminary test, the best performing lines were subjected to freezing at-11°C and -12°C. Frost tolerance was assessed measured the Fv/Fm parameter widely used to indicate the maximum quantum yield of photosystem II photochemistry in the dark adapted state. Three transgenic lines showed significantly increased tolerance. These selected lines were further studied under a complex stress applying cold and hypoxia at germinating stage. In these conditions the three selected transgenic lines outperformed the wild type barley in terms of germination vigour. The transgenic plants also showed a significant modification of their metabolism under cold/hypoxia conditions as demonstrated through the assessment of the activity of key enzymes involved in anoxic stress response. None of the transgenic lines showed dwarfism, just a slight retarded growth. These results provide evidence that the cold dependent expression of Osmyb4 can efficiently improved frost tolerance and germination vigour at low temperature without deleterious effect on plant growth.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
