New Phytologist

Alon Cna’ani, Jasmin Ravid , Moran Farhi , Tania Masci , Javiera Aravena-Calvo , Marianna Ovadis and Alexander Vainstein

The mechanism underlying the emission of phenylpropanoid volatiles is poorly understood. Here, we reveal the involvement of PH4, a petunia MYB-R2R3 transcription factor previously studied for its role in vacuolar acidification, in floral volatile emission.  We used the virus-induced gene silencing (VIGS) approach to knock down PH4 expression in petunia, measured volatile emission and internal pool sizes by GC-MS, and analyzed transcript abundances of scent-related phenylpropanoid genes in flowers.  Silencing of PH4 resulted in a marked decrease in floral phenylpropanoid volatile emission, with a concurrent increase in internal pool levels. Expression of scent-related phenylpropanoid genes was not affected. To identify putative scent-related targets of PH4, we silenced PH5, a tonoplast-localized H+ -ATPase that maintains vacuolar pH homeostasis. Suppression of PH5 did not yield the reduced-emission phenotype, suggesting that PH4 does not operate in the context of floral scent through regulation of vacuolar pH.  We conclude that PH4 is a key floral regulator that integrates volatile production and emission processes and interconnects two essential floral traits – color and scent.

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הספר "אוצר וולקני"
אודות
תנאי שימוש
Two showy traits, scent emission and pigmentation, are finely coregulated by the MYB transcription factor PH4 in petunia flowers
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Alon Cna’ani, Jasmin Ravid , Moran Farhi , Tania Masci , Javiera Aravena-Calvo , Marianna Ovadis and Alexander Vainstein

Two showy traits, scent emission and pigmentation, are finely coregulated by the MYB transcription factor PH4 in petunia flowers .

The mechanism underlying the emission of phenylpropanoid volatiles is poorly understood. Here, we reveal the involvement of PH4, a petunia MYB-R2R3 transcription factor previously studied for its role in vacuolar acidification, in floral volatile emission.  We used the virus-induced gene silencing (VIGS) approach to knock down PH4 expression in petunia, measured volatile emission and internal pool sizes by GC-MS, and analyzed transcript abundances of scent-related phenylpropanoid genes in flowers.  Silencing of PH4 resulted in a marked decrease in floral phenylpropanoid volatile emission, with a concurrent increase in internal pool levels. Expression of scent-related phenylpropanoid genes was not affected. To identify putative scent-related targets of PH4, we silenced PH5, a tonoplast-localized H+ -ATPase that maintains vacuolar pH homeostasis. Suppression of PH5 did not yield the reduced-emission phenotype, suggesting that PH4 does not operate in the context of floral scent through regulation of vacuolar pH.  We conclude that PH4 is a key floral regulator that integrates volatile production and emission processes and interconnects two essential floral traits – color and scent.

Scientific Publication