The relative decline in parameters during cold stress was compared with the baseline values.
To examine whether OsPYLs played a role during cold stress response, a cold tolerance assay was performed.
Third, OsPYL3 and OsPYL9 overexpression lines show increased membrane stability during cold stress and enhanced cold stress tolerance (Fig. 7).
Plethysmographic recording were performed every 8 s to estimate blood flow at the baseline and during cold stress induction.
In response to cold stress transcript level of OsNCX1 was specifically high, suggesting it might have some role in maintaining calcium level during cold stress.
In addition, protein SS is preferentially expressed during cold stress, suggesting that the enzyme might be involved in plant responses to low temperature stress (Crespi et al. 1991).
These findings indicated that the increased cell membrane stability of OsPYL3 and OsPYL9 overexpression lines during cold stress partially, if not totally, contributed to the observed enhanced tolerance of cold stress.
Glycosylation is also important in changing the properties and functions of proteins, so a proteomics approach was used, to analyze the importance of glycosylation during cold stress in rice [33].
Increased activities of antioxidant enzyme, including OsPOX1, APXa, and related kinase OsTrx23 (Kim et al. [2011]; Sato et al. [2011]; Xie et al. [2012]) may serve to maintain the functions of many other genes during cold stress.
Moreover, increased contents of reactive oxygen species (ROS) and malondialdehyde (MDA) that accumulate during cold stress in rice can impair metabolism via cellular oxidative damage (Xie et al. [2009]; Nakashima et al. [2007]).
Among the genes up-regulated during cold stress recovery, many encode membrane-related proteins [30].
