We investigated the role of auxin on stem elongation in pea (Pisum sativum L.) grown for 10 d in continuous darkness or under low-irradiance blue, red, far red and white light. The third internode of treated seedlings was peeled and the tissues (epidermis and cortex+central cylinder) were separately analyzed for the concentration of free and conjugated indole-3-acetic acid (IAA). Under red, far red and white light internode elongation was linearly related with the free IAA content of all internode tissues, suggesting that phytochrome-dependent inhibition of stem growth may be mediated by a decrease of free IAA levels in pea seedlings. The correlation between IAA and internode elongation, however, did not hold for blue light-grown seedlings. The hypothesis that the growth response under low-irradiance blue light might be correlated with the lack of phytochrome B signalling and changes in gibberellin metabolism is discussed in view of current knowledge on hormonal control of stem growth.
|Autori:||SORCE C; PICCIARELLI P; CALISTRI G; LERCARI B; CECCARELLI N|
|Titolo:||The involvement of indole-3-acetic acid in the control of stem elongation in dark- and lightgrown pea (Pisum sativum) seedlings|
|Anno del prodotto:||2008|
|Digital Object Identifier (DOI):||10.1016/J.JPLPH.2007.03.012|
|Appare nelle tipologie:||1.1 Articolo in rivista|