*4.8. Northern Hybridization*

Northern hybridization was performed as previously described [9,10]. Briefly, total RNA was isolated using TRIzol (Invitrogen, Waltham, MA, USA) from the cells that were harvested at several time points after applying salt stress under high light conditions. The total RNA (10 μg) was subjected to electrophoresis in 1.0% agarose gels, blotted onto nylon Hybond N+ membranes (Amersham, Chicago, IL, USA) were probed with the PCRamplified DNA fragment encoding the target region. The identity of the amplified DNA fragment was confirmed by size and nucleotide sequence. The RNA was pre-hybridized at 60 ◦C for 30 min, and the 32P-labeled DNA probe was hybridized to RNA on the membrane at 60 ◦C for 12 h.
