LC-ES/MS Detection and quantification of chemical species related to reactive oxygen species and nitric oxide (NO) metabolism in olive pollen (Olea europaea L.) throughout in vitro pollen germination

Resumen del póster presentado al Plant Biology Congress, celebrado en Friburgo (Alemania) del 29 de julio al 3 de agosto de 2012.
ROS and NO are low molecular weight molecules implicated in plant signalling. Their relevant implication in pollen tube growth and reorientation has been shown particularly in plant model species. In olive reproductive tissues, their presence has been described in a stage- and tissue- specific manner. Accurate detection and quantification of minor changes in ROS/NO and the chemical species resulting or interacting with their metabolism in reproductive tissues is a challenging task at present. The goal of the present study was to elucidate the implication of the NO metabolism in the process of olive pollen germination in vítro. For this purpose we used a recently published method based in the use of liquid chromatography-electrospray/mass spectrometry to detect different antioxidant metabolites in volved in NO metabolism. We have analysed the levels of key molecules like GSH (reduced glutathione), GSSH (oxidized glutathione), GSNO {Snitrosoglutathione) and ascorbic acid (vitamin e) in the mature pollen, and the pollen grain and pollen tube at different times of in vitro germination. These data correspond to both dormant and activated metabolism, respectively. The results revealed remarkalble changes in the levels of GSNO, which is a cellular NO reservoir, throughout the germination process. These data confirm the involvement of NO and antioxidant molecules in the pollen tube growth, as observed previously by using CLSM, and point to potential new specific roles for these molecules as signalling intermediates.
Work supported by ERDF-cofounded project MCINN BFU2011-22779. MJJQ and AZ thanks JAE grant funding.