Global analysis of gene expression in maize leaves treated with low temperature

Chilling affected 440 (4 h) or 155 (28 h) transcripts. After 4 h, 59 transcripts showed aberrant response to photoperiod, suggesting diurnal clock disruption as a mechanism by which chilling affects maize physiology. GO-based analysis indicated modification of cell wall properties as another early response. Few photosynthesis-related genes were repressed by chilling, despite the popular notion that photosynthetic apparatus is a major target of cold. Conversely, induction of chloroplast-related genes not directly engaged in photosynthesis was evident at later stages of the response. Numerous transcripts strongly affected by chilling were of unknown function; they may encode novel activities crucial in maize response to chilling and deserve detailed studies.